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AUTHOR: 
 
 MERCIER, CHARLES 
 ARTHUR 
 
 TITLE: 
 
 ON CAUSATION 
 
 PLA CE: 
 
 LONDON 
 
 DA TE : 
 
 1916 
 
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 Mercier, Charles A^rthurj, 1852-1919. 
 
 On causation, with a chapter on belief... 
 London, Longmans, 1916. 
 
 xii, 228 p. 25 cm. 
 
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!4 
 
 CAUSATION AND BELIEF 
 
Had I not continually exercised my judgement, the greater 
 part of the books on these subjects would have turned my brain. 
 This effect they have certainly had upon many who have not 
 used the same precaution. I know the advantage which I might 
 derive from perplexing the understanding by recurring to 
 abstruse reasoning and logical quibbles. But I wave it all. I 
 shall speak nothing but common sense, and what may be under- 
 stood by anyone, however slender his acquirements. 
 
 — Home Tooke. 
 
 I myself frequently meditate by myself long and intently ; 
 but in vain; unless I find an antagonist, I have no hope of 
 success.— ^ca/jg'^. 
 
 ON 
 
 CAUSATION 
 
 WITH 
 
 A CHAPTER ON BELIEF 
 
 BY 
 
 CHARLES A. MERCIER, M.D., F.R.C.P., F.R.C.S. 
 
 • %^ 
 
 AUTHOR OF 
 
 CRIMINAL RESPONSIBILITY'; ' PSVCHOLOGV, NORMAL AND MORBID'; ,_ 
 'a new logic' ; 'CONDUCT AND ITS DISORDERS* ; ' A TEXT-BOOK 
 OF INSANITY'; 'CRIME AND INSANITY'; 'ASTROLOGY 
 IN MEDICINE ' ; ETC., ETC. 
 
 i 
 
 LONGMANS, GREEN AND CO, 
 
 39 PATERNOSTER ROW, LONDON, E.G. 
 
 Fourth Avenue and 30TH Street, New York 
 
 Bombay, Calcutta, and Madras. 
 
 1916 
 
'/7-2.ciO0/ 
 
 PRIMTID BY ADLAKD AND ION AND WEST NEWMAN, LONDON AND DORKING. 
 
 ct: 
 
 TO THE MEMORY 
 
 OF 
 
 THE BEST WIFE EVER MAN HAD 
 
 12Z 
 
CONTENTS. 
 
 Preface 
 
 PAGE. 
 
 CHAPTER I. 
 
 Some Theories of Causation. Hume, Mill, Mr. Welton, Professor 
 Pearson, Mr. Bertrand Russell, Dr. McTaggart 
 
 CHAPTER II. 
 
 Effect, Reason, Result, Cause 
 
 35 
 
 CHAPTER III. 
 
 Condition 
 
 49 
 
 CHAPTER IV. 
 
 Causation 
 
 6i 
 
 CHAPTER V. 
 Subsidiary Problems . 
 
 • • • • 
 
 Plurality of Causes ... 
 Regression of Causes and Progression of Effects '. 
 Radification of Causes and Ramification of Effects 
 Cooperation of Causes 
 
 ' • • , 
 
 The Law of Causation 
 The Uniformity of Nature 
 
 * • • 
 
 7» 
 
 7» 
 8a 
 
 82 
 
 87 
 95 
 
vni 
 
 CONTENTS. 
 
 CHAPTER VI. 
 
 Methods of Ascertaining Causes . 
 
 . 192 
 
 CHAPTER vn 
 
 Errors in Attributing Causation . 
 
 CHAPTER THI. 
 Causes of Death. Causes of Insanity 
 
 . 148 
 
 . 167 
 
 CHAPTER IX 
 
 On Belief 
 
 . 188 
 
 PREFACE, 
 
 Exasperated by the fatuity of an expert in heraldry whom 
 he was cross-examining, Sir William Harcourt at length 
 exclaimed : * Why, the silly man does not understand even 
 his own silly business ! ' The reader of a book on orthodox 
 Logic is constantly tempted to make the same comment. Every 
 book on Inductive Logic contains a chapter in which an attempt 
 is made to investigate the nature of Causation, to define it, and 
 to explain how causes are ascertained and assigned ; but why 
 Causation should be considered subject-matter of Logic, any 
 more than rotation or imitation, is hard to understand. ' The 
 proper task of Logic is to describe and explain the principles 
 and methods of reasoning, and causation is not a principle or 
 method of reasoning, nor is the definition of causation or the 
 ascertainment of causation a principle or method of reasoning. 
 These are applications of reasoning. They are examples of 
 reasoning. The results are arrived at by methods of reasoning, 
 but they are not themselves methods or principles of reasoning,* 
 and are, therefore, no part of Logic. Mill says, and all sub- 
 sequent writers have followed him, that causation lies at the 
 very root of Induction. It does nothing of the sort It is 
 one of very many relations that may be discovered by Induc- 
 tion, but it is no more the basis of Induction than rotation or 
 imitation is the basis of Induction. 
 
 However, logicians have appropriated to themselves the 
 examination of causation, and it is not surprising, therefore, 
 that its true natqre has never been discovered, and that the 
 
X 
 
 PREFACE. 
 
 subject is entangled in confusion and contradiction ; for it is 
 thus that logicians leave the subjects they investigate. Mill 
 is the model and great exemplar, as well as the leader of 
 latter-day logicians, and though it may almost be said that men 
 of all sorts take a pride to gird at him, yet it may also be said 
 that he is not only confused and muddled in himself, but the 
 cause of confusion and muddle that are in other men. He 
 enumerates five Methods of Experimental Inquiry, and he calls 
 them four, and in seventy years not one of his commentators has 
 discovered the inaccuracy ; some of his most important terms, 
 such as effect and condition, he never defines at all ; others, 
 such as cause, causation, and conditionality, he defines over 
 and over again in senses that are difierent, incongruous, or 
 inconsistent ; his Canons for discovering causes are cumbrous, 
 uncouth, and clumsy in expression, and in meaning are absurd. 
 They never have been used, and never could be used. It is 
 time, therefore, to take the matter out of the hands of logicians, 
 and investigate it by the light of common sense. 
 
 Everyone has an approximate notion, good enough for most 
 working purposes, of what is meant by causation, and by cause 
 and effect, but no one has been able to put that notion into a 
 verbal expression that will stand criticism, and some of the 
 attempts to do so have resulted in expressions that are pre- 
 posterous beyond belief, as will appear when they are examined. 
 It may seem that if we know what we mean with sufficient 
 accuracy for working purposes, this is enough, and we need not 
 strive to attain pedantic precision ; but apart from the general 
 desirability of defining our terms, the approximate accuracy 
 which is enough for rough working purposes is not enough 
 when subtle, intricate, and important problems have to be 
 determined. Issues involving the determination of causes are 
 frequently brought before Courts of Law, and of late years such 
 issues have become much more frequent in connection with 
 causes of disease, of death, of accident, and of injury. In 
 trying such cases, judges have expressed the embarrassment 
 they have suffered from the want of a trustworthy definition of 
 cause. Many nice points of causation have lately come 
 before the Courts, and have been decided in the absence of 
 
 PREFACE. 
 
 XI 
 
 any clear or precise notion of what causation consists in 
 without that guidance from philosophers which judges have a 
 right to expect. They have looked to philosophers for h^ht 
 and order and they have found Cimmerian darkness and 
 primseval chaos. 
 
 Nor is it only in the determination of individual issues that 
 a knowledge of the nature of causation is important in law 
 A definition of causation, or at least a clear knowledge of what 
 causation means and is, is the root and the basis of one verv 
 important department of law, reference to which is made in 
 every case that is tried in the Courts. It is the basis of the 
 Lavv of Evidence According to that very high authority, Mr. 
 Justice Stephen, the facts that may be proved in Courts of Law 
 are the facts in issue, and those facts that are relevant to the 
 issue and he defines relevancy thus : ' A fact is relevant to 
 another fact when the existence of the one can be shown to be 
 the cause or one of the causes, or the effect, or one of the 
 effects, of the existence of the other,' etc. Clearly, then to 
 determme what facts are relevant, and this has to be determined 
 many times in the course of every trial, a knowledge of what 
 IS meant by causation, and of the nature of cause and of effect is 
 necessary. Mr. Justice Stephen, in fact, says that his work on 
 Evidence is founded on Mill's Logic, and that a previous work 
 on the Law of Evidence is founded upon Locke's ' Essay ' As 
 
 M t" r'^'r r'^' ' '^" ^'^' "° °P'"'°"' ^^' I ^"^ su;e that 
 Mr. Justice Stephen was mistaken when he said his work was 
 
 founded upon Mill's Logic, for his treatise on the Law of 
 
 Evidence IS as clear and consistent as Mill's Logic is the opposite. 
 
 Mr. Justice Stephen's admission is important, however as 
 
 showing that in his opinion the Law of Evidence does ne^d a 
 
 loundation in a proper apprehension of Causation 
 
 In other important matters also the need for a clear notion 
 
 of the meaning of cause and effect is imperative, and the want 
 
 of It leads to grave disadvantages. The instructions issued by 
 
 the General Register Office for assigning the causes of death 
 
 are such that no doctor can understand them, and their unintelli- 
 
 g.bihty ,3 owing to the want of a definite notion of cause The 
 
 causes of insanity published in the annual tables of the Board 
 
XII 
 
 PREFACE. 
 
 Of Control are mostly guesses ; some of them are manifestly 
 not causes at all ; others may or may not be causes but no 
 reason is given why they should be so considered ; and in the 
 absence of any definition of a cause, and of any trustworthy 
 method of assigning causes, no reason could be given. 
 
 It is always assumed by writers on the subject that the only 
 investigations that are worth making into the methods of 
 assigning causes are investigations into the methods pursued 
 by scientific workers, and that result in scientific discoveries. 
 These writers, following Mill, formulate five methods, which, as 
 I have said, they count as four, which they say are used by 
 scientific workers. Scientific workers, however, never use these 
 methods, and could not use them, for they are utterly futile, 
 as will hereinafter appear. Moreover, the assumption that the 
 methods employed by scientific workers to discover causes are 
 in any respect different from the methods employed in every- 
 day life by the cook, the gardener, the plumber, and the rest of 
 us is quite groundless and mistaken. Men who work at science 
 have no monopoly of methods of discovering causes. Their 
 methods are not novel or peculiar, but are the same as those 
 that we all constantly use in the course of our daily lives. For 
 this reason I have not followed the course usual in books on 
 Causation, of restricting my illustrative instances to examples 
 of discoveries in science. 
 
 The chapter on Belief has been added at the request of a 
 friend who, like most of us, has found himself often puzzled 
 what to believe and what to disbelieve. It makes no preten- 
 sions to philosophical profundity, and to those who are 
 accustomed to the ponderous tomes that have been written on 
 the foundations of belief, and upon epistemology generally, it 
 will appear, I am afraid, a trifling performance. These books 
 however, are scarcely accessible to the general reader, and if 
 thev were it is doubtful whether he would take advantage of 
 them Some work accessible to him and intelligible by him 
 is sorely needed. It is curious that in an age that prides itself 
 before all things upon being scientific, there are as many pre- 
 valent beliefs that are irrational, baseless, absurd, and self-cori- 
 tradictory, as at any former time of which we have any record. 
 
 CHAPTER I. 
 SOME THEORIES OF CAUSATION. 
 
 In the whole of philosophy, confused as it is, there is scarcely 
 any subject in such utter confusion as causation. There are 
 references to it in the writings of his predecessors, but Hume 
 was tlie first writer of note who discussed it at length, and he 
 got it into a tangle which has been worse and worse entangled 
 by subsequent writers, until the latest contributors to the dis- 
 cussion have essayed to cut the knots by denying altogether 
 that there is such a thing as causation at all. Few writers 
 treat the subject without contradicting themselves, and none 
 without outraging common sense, a result which does not 
 trouble them, for the first qualification for a philosopher is to 
 set common sense at defiance. The consequence is that no 
 one who retains any remnant of common sense can rise from 
 the perusal of a discussion of causation without a feeling of 
 dazed perplexity. He finds long discussions in which the 
 cardinal terms are used in several different senses, and are 
 either defined in several different ways or never defined at all. 
 He finds things that are quite distinct, such as cause, condition, 
 .and agent, confounded together ; he finds problems that are' 
 quite distinct, such as the nature of causation and the univer- 
 sahty of causation, confounded together ; and through all the 
 discussions runs the difficulty inherent in examining and 
 defining a notion that is almost primitive. 
 
 Primitive notions are by their very nature impossible to 
 
 I 
 
 4 
 
ON CAUSATION. 
 
 define or explain satisfactorily. They can only be described, 
 and even description is not always easy or always satisfactory. 
 Matter cannot be described except in terms of force, nor force 
 except in terms of matter. It is manifest that defining and 
 explaining more complicated notions in terms of simpler notions 
 cannot be continued indefinitely. The process reaches its 
 natural limit when at last we come to notions of primitive 
 simplicity, just as the chemical analysis of substances reaches 
 its natural limit when we have at last reduced them to elements. 
 The notion of causation is almost elementary. Cause and 
 effect, like matter and force, are terms that everyone under- 
 stands more or less vaguely, more or less precisely, but that it 
 is diflRcult to express more simply for want of simpler terms. 
 At any rate it has been found impracticable hitherto to ex- 
 press them, for every effort that has been made to do so has 
 resulted in an expression that is either more obscure than 
 cause and effect themselves, or that does not truly express what 
 they mean. 
 
 Dr. Fowler says * That a cause is ... ; that every event 
 has a cause ; that the same cause is always attended by the 
 same effect ; are obviously three different propositions, and 
 still there are few writers who in their treatment of the ques- 
 tion of causation have not more or less confounded them.* 
 This is quite true, and he might have added a fourth — we derive 
 our notion of causation from ... or the origin of our notion 
 of causation is . . . 
 
 It is this fourth proposition that is the main theme of 
 Hume's discussion, and he arrived at the conclusion, which is 
 no doubt correct, that we get our notion of causation from 
 witnessing repeated instances of it — that, in fact, as we should 
 say now, it is a generalisation from many individual experi- 
 ences. So far no doubt he was right ; but he went on to 
 assume, and his whole argument rests upon the assumption, 
 that because the notion of causation is a generalisation from 
 repeated experiences, therefore causation itself does not exist in 
 isolated or single instances, and, in fact, does not exist at all, but 
 is a mental fiction, without any corresponding relation in fact. 
 
 The common sense doctrine that Hume undertook to de- 
 
 SOME THEORIES OF CAUSATION. ' 3 
 
 tiiolish is ' that the idea of causation necessarily implies the 
 Idea of power or necessary connection, that is to say, between the 
 cause and the effect, or power in the cause to produce the 
 effect. ^ He set himself to show that power and necessary 
 connection had been illegitimately imported into the idea of 
 causation, and that what we call cause and effect is nothing 
 but casual antecedence and consequence. Antecedence and 
 consequence are all that we ever observe, or can observe • but 
 when vve have witnessed many instances of the same antecedent 
 benig followed by the same consequent, we jump to the con- 
 elusion, without any justification for doing so, that there is 
 between them a tie other and more than bare sequence— that 
 there is a power in the antecedent to bring about the con- 
 sequent, and a necessary connection between them. Thus 
 Hume teaches. 
 
 Briefly put, his argument is that all our ideas are in the last 
 resort analysable into simple ideas, which are themselves copies 
 of impressions or original sentiments, by which he seems to 
 mean what we now call percepts. ' These impressions are 
 strong and sensible. They admit not of ambiguity.' Such 
 are solidity, extension, and motion, each of which we can per- 
 ceive, so Hume teaches, in a single experience ; ' but the 
 power of force . . . is entirely concealed from us, and never 
 discovers itself in any of the sensible qualities of body ' He 
 means, apparently, that we cannot see it : ^ It is impossible^ 
 therefore, that the idea of power can be derived from the con- 
 templation of bodies in single instances of their operation • 
 because no bodies ever discover any power which can be the 
 original of this idea.' Since, then, we obtain the nbtions of 
 force or power and necessary connection, not from single expe- 
 riences, but by generalisation from many experiences these 
 notions are fictitious, imaginary, and have no basis in fact 
 neither have they any existence except in our own misguided 
 imaginations. This is Hume's doctrine. 
 
 ^ It is very curious that this doctrine should have been prac- 
 tically accepted by every writer since Hume's time, and that 
 no present-day philosopher should have detected any of the 
 -fallacies in it. Modern psychologists are pretty familiar I 
 
 iii- 
 

 A ON CAUSATION. 
 
 should have thougnt, with the doctrine that every one of our 
 concepts of the simplest properties of bodies— solidity, exten- 
 sion, motion, and the rest— is a generalisation from many 
 experiences, and is in no case derived from a single instance, 
 but is slowly built up in our early years under the guidance of 
 experience. As far and in the same way as solidity, extension, 
 i and motion are revealed to us by experience, so far and in that 
 ! way is force or power ; and if force or power is not revealed in 
 la single instance, neither is existence, extension, or motion. 
 The only force that exists wholly in the imagination, and is 
 without any counterpart outside it, is the force of Hume's 
 
 argument. 
 
 'The generality of mankind never find any difficulty m 
 accounting for the more common and familiar operations of 
 Nature,such as the descent of heavy bodies . . . but suppose 
 that, in all these cases, they perceive the very force or energy of 
 the cause by which it is connected with its effect and is for ever 
 infallible in its operation. They acquire, by long habit, such a 
 turn of mind that upon the appearance of the cause they 
 immediately expect, with assurance, its usual attendant, and 
 hardly conceive it possible that any other event could result 
 from it.' They do, undoubtedly ; but are they not justified 
 in so accounting for these operations of Nature ? What is the 
 test ? What is the inexpugnable, infallible test ? It is that, 
 acting on this supposition, they should never meet with expe- 
 rience that contradicts it ; and is not this test satisfied ? Hume 
 says that force or power is never revealed in a single instance ; 
 out, when the mind has been prepared by previous experiences 
 to entertain the notion, is not the single instance of carrying a 
 bucket of water sufficient to reveal the force or power of the 
 weight of the bucket? If a breaking wave, thundering upon 
 the beach, and carrying away cartloads of shingle in the 
 undertow, does not convey the idea of force or power ;^ if a 
 hurricane, uprooting great trees, unroofing houses, and whirling 
 haystacks into the air, does not convey the idea of force or 
 power ; if an avalanche, carrying away woods and villages, and 
 diverting the course of torrents, does not convey the idea of 
 force or power ; then no * contemplation of any body in 
 
 SOME THEORIES OF CAUSATION. J 
 
 -single instances of its operation ' can afford any idea of any 
 description. 
 
 Hume denies that we derive the idea of power from subjec- 
 tive experience, from finding * that by the simple command of 
 the will we can move the organs of our body or direct the 
 functions of our mind.' He denies it on the ground that * we 
 learn the influence of our will from experience alone, and 
 experience only teaches us how one event constantly follows 
 another ; without instructing us in the secret connection which 
 binds them together and renders them inseparable.' But why 
 should it ? We might as well deny that we derive from expe- 
 rience the idea that glue sticks to wood, because we know it from 
 experience alone, and experience does not instruct us in the 
 secret connection which binds the glue and the wood together 
 and renders them inseparable. 
 
 Thus he summarises his conclusions : * It appears that, in 
 single instances of the operation of bodies, we never can, by our 
 utmost scrutiny, discover anything but one event following 
 another, without being able to comprehend any force or power 
 by which the cause operates, or any connection between it and 
 its supposed effect. ... All events seem entirely looser 
 and separate. One event follows another ; but we never can! 
 observe any tie between them. They seem conjoined, but never! 
 connected: Thus he virtually denies causation altogether, and j 
 as we shall see later, recent writers accept this conclusion, and 
 bring it forward as original with themselves ; but it is clear 
 that this is Hume's position, though he never actually puts it 
 into these words. Having arrived at this conclusion, which is 
 a virtual denial that there is any such thing as causation, he 
 admits that when a man has observed several similar instances 
 •of such conjoined events he ' can readily foretell the one from 
 the appearance of the other ' ; and then Hume astounds us by 
 defining a cause as ' where, if the first object had not been, the 
 second had never existed! It would be difficult to put the 
 necessary connection between them in stronger terms, and 
 Hume seems frightened at having made the admission, for he 
 begins at once to hedge, and offers another, his third, definition 
 «of a cause : an object followed by another^ and whose appearance 
 
 f 
 
 I 
 
 ^ 
 
ON CAUSATION. 
 
 SOME THEORIES OF CAUSATION. 
 
 )} 
 
 always conveys the thought to that other. Thus he removes the 
 reference from the world of things to the world of thoughts, 
 and places the matter on an entirely different basis. At length 
 he concludes : * I know not whether the reader will readily 
 apprehend this reasoning. I am afraid that, should I multiply 
 words about it, or throw it into a greater variety of lights, it 
 would only become more obscure and intricate.' In this he is 
 no doubt right. His argument is based on a premiss that is 
 thoroughly unsonnd, and leads to a conclusion that is repugnant 
 to universal experience, and that he is himself compelled to 
 repudiate. However, the mischief was done. He opened the 
 floodgates of confusion, and his successors have ever since been' 
 floundering in the swamp. 
 
 Mill's whole treatment of the problem of causation is a most 
 deplorable muddle, and that he should have been regarded as 
 an oracle for two generations is a startling proof of the 
 poverty of critical acumen and philosophic insight that has 
 prevailed since his Logic appeared. It is evident on the most 
 superficial perusal of his chapters on the subject that he has 
 never thought it out ; he wanders on from conjecture to 
 surmise, and from surmise to conjecture, stating his surmises 
 and conjectures as inexpugnable facts ; he defines cause and 
 causation over and over again in eighteen different ways, most 
 of them inconsistent with each other, and some of them contra- 
 dictory of others, and neither he nor his commentators and 
 followers recognise the inconsistencies or the contradictions. 
 The only explanation of his astonishing and overwhelming 
 reputation is that amongst the blind the one-eyed is king ; but 
 even Mill's one eye was purblind. 
 
 Mill first states Hume's doctrine in its bare nakedness : 
 ' The Lav/ of Causation ... is but the familiar truth, 
 that invariability of succession is found by observation to 
 obtain between every fact in Nature and some fact that has 
 preceded it.' It may be noted in passing that however familiar 
 and however true this may be, it is certainly not found by 
 observation, and Mill's study of Hume should have warned him 
 not to make so absolute an assertion ; for Hume says very 
 truly ' on the discovery of extraordinary phenomena, such as 
 
 earthquakes, pestilence, and prodigies of every kind, they find 
 themselves at a loss to assign a proper cause,' and there are 
 still innumerable facts in nature which baffle all our attempts 
 to discover their causes. However, Mill goes on : 'To certain 
 facts, certain facts do, and, as we believe, will continue to 
 succeed. The invariable antecedent is called the cause ; the 
 invariable consequent, the effect.' He does not recognise that 
 this statement differs very materially from the former. First 
 he says that every fact has an invariable antecedent, and then 
 he says that every fact has an invariable consequent, and he 
 regards the two assertions as equivalent. In his next statement 
 he goes back to his first position, and says : ' The universality 
 of the law of causation consists in this, that every consequent 
 is connected in this manner [invariably] with some particular 
 antecedent, or set of antecedents.' In this he airily gives away 
 Hume's whole position, and introduces a new and vitally 
 important element, without in the least recognising that he is 
 doing more than restating his previous doctrine. The ante- 
 cedent now not only invariably precedes the consequent, but 
 also is connected with it, a doctrine which Hume positively 
 denies, and which, when introduced into what is virtually a 
 restatement of Hume's doctrine, requires at least some 
 justification or explanation ; but none is given. 
 
 As is well known, Reid demolished Hume's definition of 
 causation as invariable succession by adducing the case of night 
 and day. Night invariably follows day, and day invariably 
 follows night, and yet neither is the cause of the other. Clearly, 
 some qualification and addition is necessary, and Mill, though 
 he gives the expressions quoted above as complete and sufficient 
 statements of the nature and relation of cause and effect, 
 evidently recognises that some qualification and addition is 
 required, and supplies one, in fact, he supplies a good many, not 
 as successive approximations to a complete definition, not as 
 tentative proposals to be discarded when found inappropriate, 
 but all of them as final and complete definitions, which are 
 immediately superseded by others, which are superseded in their 
 
 turn. 
 
 It is very common, he says, when there are many antecedents 
 
8 
 
 ON CAUSATION. 
 
 't 
 
 (as if there were ever an effect that had not many antecedents, 
 and he does not say invariable antecedents connected with the 
 consequent, though presumably he means such antecedents) to 
 single out only one of them under the denomination of cause, 
 calling the others merely conditions. * But though we may 
 think proper to give the name of cause to that one condition, 
 the fulfilment of which completes the tale, and brings about 
 the effect without further delay ; this condition has really no 
 closer relation to the effect than any other of the conditions 
 has.' This leads him to his fourth definition, different from all 
 the rest. ' The cause, then, philosophically speaking, is the 
 sum total of the conditions, positive and negative taken 
 together ; the whole of the contingences of every description, 
 which being realised, the consequent invariably follows.' 
 
 Having given this final definition of what the cause is, 
 philosophically speaking, he discusses it further, and finds that it 
 won't do. He now finds it necessary * to advert to a distinction 
 which is of first-rate importance,' which, in spite of its first-rate 
 importance, has been omitted from his previous definitions. 
 Invariable sequence is not synonymous, he now finds, with 
 causation, unless the sequence, besides being invariable, is also 
 unconditional ; and this he says immediately after he has 
 defined the cause as * philosophically speaking,' the sum total 
 of the conditions. It is, therefore, philosophically speaking 
 conditional, and speaking otherwise unconditional. This leads 
 him to his fifth definition, according to which a cause is ' the 
 antecedent, or the concurrence of antecedents, of a phenomenon, 
 on which it is invariably and tmconditionaliy consequent.' Still 
 dissatisfied, as well he may be, he tries again, and gives a sixth 
 definition, ' which confines the meaning of the word cause, to 
 the assemblage of positive conditions without the negative, and 
 then, instead of unconditionally, we must say " subject to no 
 other than negative conditions " ' ; and if this does not satisfy, 
 he has 'no objection to define a cause, the assemblage of 
 phenomena, which occurring, some other phenomenon invariably 
 commences or has its origin.' So that after asserting in the 
 most positive terms that invariable sequence is not causation 
 unless the sequence, besides being invariable is also uncondi- 
 
 SOME THEORIES OF CAUSATION. 
 
 iional, he now drops unconditionalness, and goes back without 
 a word of apology to invariable sequence. 
 
 It would be tedious and unprofitable to examine any further 
 the mass of confusion and contradiction contained in Mill's 
 exposition of causation, but lest it should be thought that I 
 have at all exaggerated, Ivvill set down here a series of extracts 
 from his Logic. 
 
 He prefaces his discussion of causation with the following 
 warning : ' The notion of cause being the root of the whole 
 theory of Induction [it is not], it is indispensable that this idea 
 should, at the very outset of our inquiry be, with the utmost 
 practicable degree of precision, fixed and determined.' This he 
 says, and more than two hundred pages later he is still altering 
 his definition of cause ; more than three hundred pages later he 
 alters his definition of causation. This is how he fixes and 
 determines his notion of cause with the utmost practicable 
 degree of precision : — 
 
 ' The Law of Causation ... is but the familiar truth 
 that invariability of succession is found by observation to obtain 
 between every fact in Nature and some other fact which has 
 preceded it.' I, 376. 
 
 ' The invariable antecedent is termed the cause, the invariable 
 consequent, the effect.' I, '^yy. 
 
 • If it [the fact] has begun to exist, it was preceded by some 
 fact or facts with which it is invariably connected.' I, 377. 
 
 V 'The real Cause is the whole of those antecedents.' I 
 
 ' All the conditions were equally indispensable to the pro- 
 duction of the consequent ; and the statement of the cause is 
 incomplete unless in some shape or other we introduce them 
 ^^^•' ^ 379- Condition is not defined. 
 
 * The cause, then, philosophically speaking, is the sum total 
 of the conditions, positive and negative, taken together ; the 
 whole of the contingencies of every description, which being*' 
 realised, the consequent invariably follows.' I, 383. Contin- 
 gency is not defined. 
 
 ' Lt is necessary to our using the word cause, that we should 
 believe not only that the antecedent always has been followed 
 
lO 
 
 ON CAUSATION. 
 
 by the consequent ; but that, as long as the present consti- 
 tution of things endures, it always will be so.' I, 391- 
 
 ' That which will be followed by a given consequent when, 
 and only when, some third circumstance also exists, is not the 
 cause, even though no case should have occurred in which the 
 phenomenon took place without it.' I, 392. 
 
 ' Invariable sequence, therefore, is not synonymous with 
 causation, unless the sequence, besides being invariable, is 
 
 unconditional' I, 392. 
 
 * We may define, therefore, the cause of a phenomenon, to be 
 the antecedent, or concurrence of antecedents, on which it is 
 invariably and iniconditionally consequent ' ; or 
 
 ' The antecedent, or the concurrence of antecedents, on which 
 it is invariably and subject to no other than negative conditions 
 
 consequent' ; or 1 - u- 1 
 
 * The antecedent, or the concurrence of antecedents, in which 
 it is invariably and whatever supposition we may make about 
 other things, consequent.' I, 392. 
 
 ' The series of the earth's motions, therefore, though a case 
 of sequence invariable within the limits of human experience, is 
 not a case of causation.' 1,394- 
 
 ' I have no objection to define a cause, the assemblage of 
 phenomena, which occurring, some other phenomenon invariably 
 commences, or has its origin.' I, 397- 
 
 ' There is no Thing produced, no event happening in the 
 known universe, which is not connected by an uniformity, or 
 invariable sequence, with some one or more of the phenomena 
 which preceded it.' I, 400. 
 
 ' The state of the whole universe at any instant, we believe 
 to be the consequence of its state at the preceding instant.** 
 
 I, 400. - 
 
 * The law of causation is, that change can only be produced 
 
 by change.' I, 407. . . 
 
 ' In this example we may go further, and say, it is not only 
 
 the invariable antecedent but the cause.' I, 450. 
 
 The cause of it, that is, the peculiar conjunction of agent.s 
 
 from which it results.' I, 5 ^ ^• 
 
 That which would not be followed by the effect unless- 
 
 I 
 
 SOME THEORIES OF CAUSATION. 
 
 I r 
 
 something else had preceded, and which if that something else 
 had preceded, would not have been required, is not the cause, 
 however invariable the sequence may in fact be.' II, IJ, 
 
 * Fresh causes or agencies.' II, 38. 
 
 * The uniformity in the succession of events, otherwise called 
 the law of causation.' II, 108. 
 
 From these dicta we may extract the following definitions or 
 descriptions of cause, and in repeating them I will put in 
 italics the words which are discordant or incongruous with 
 previous utterances. 
 
 A cause is : 
 
 ( 1 ) The invariable antecedent. 
 
 (2) The preceding fact with which the effect is invariably 
 cojinected. 
 
 (3) The whole of the antecedents. 
 
 (4) All the condifio7is. 
 
 (5) The sum total of the conditions. 
 
 (6) The whole of the contingencies. 
 
 (7) The antecedent which not only always has been 
 followed, but that always will be followed by the consequent ; 
 although 
 
 (8) That which always has been and always will be follovved 
 by the consequent is not necessarily the cause. 
 
 (9) The invariable unconditional antecedent. • - 
 
 (10) The antecedent on which the effect is invariably and 
 subject to no other than negative conditions consequent. 
 
 (11) The antecedent on which the effect is invariably con- 
 sequent whatever siippositions we may make about other things. 
 
 (12) The assemblage of pJienomefia, which occurring, some 
 other phenomenon commences or has its origin. 
 
 (13) The peculiar conjunction of agents from which the con- 
 sequence results. 
 
 (14) An agency. 
 
 Causation, or the Law of Causation, is : 
 
 (i) Invariability in succession. 
 
 {a) Invariable arid unconditional sequence. 
 
 (3) Uniformity \n the succession of events. 
 
 (4) That change can only be produced by change. 
 
12 
 
 ON CAUSATION. 
 
 i 
 
 In addition to the discordances in these definitions, account 
 must be taken of the following pairs of assertions : 
 
 * Causation is invariability of succession.' 
 
 * The series of the earth's motions, though a case of sequence 
 invariable within the limits of human experience, is not a case 
 
 of causation.' 
 
 ' The cause is the invariable antecedent.' * The invariable 
 
 antecedent is the cause.' 
 
 'That which would not be followed by the effect unless 
 something else had preceded, and which if that something else 
 had preceded, would not have been required, is not the cause, 
 however invariable the sequence may in fact be.' 
 
 ' Causation is invariability of succession.' 
 
 * Invariability of sequence is not synonymous with causation 
 unless the sequence, besides being invariable, is unconditional.' 
 
 The majority of writers since Mill have followed rather 
 slavishly in his footsteps, but a few recent writers have struck 
 out more independent courses, and some of these must be 
 examined. I confine the examination to the writings of Mr. 
 Welton, Prof. Karl Pearson, Mr. Bertrand Russell, and Dr. 
 
 McTaggart. 
 
 Mr. Welton accepts Mill's doctrine that the cause is the sum 
 of the conditions, though he prefers to call it the totality of the 
 conditions, but he rejects altogether the time factor, or ante- 
 cedence and consequence, which every previous writer on the 
 subject considers a necessary ingredient in our concept of 
 causation. ' The cause,' he says, * is not dependent on time 
 sequence. For if we analyse any case of causation we find that 
 time sequence is not an essential aspect of it.' I am not so 
 sure, data cavat lapidem. The continual dropping of water 
 JAvears away a stone, and surely this takes time. The ploughing, 
 harrowing, and sowing of the ground are causes of the subse- 
 <iuent harvest, but the harvest is not simultaneous with these 
 operations. It gradually matures for months, and not until 
 
 (months have elapsed is the effect produced. The admini- 
 stration of an excess of food causes a pig to gr6w fat, but the 
 pig does not instantaneously explode into a state of obesity. 
 Perhaps, however, in giving these examples I should be tripped 
 
 SOME THEORIES OF CAUSATION. 
 
 15 
 
 Up by the expression, * essential aspect.' What an essential 
 aspect may be I do not know, but whatever it is, I find it hard to 
 reconcile Mr. Welton's assertion with his subsequent assertion 
 that the fact to be accounted for is change. Change, he says, 
 implies something which changes. So it does, but it implies 
 something else also. It implies duration. We speak of 
 instantaneous changes, but in fact and in Nature there is no 
 such thing. Change implies duration. It implies an ante- 
 cedent state from which, and a subsequent state to which, the 
 change takes place. If the fact to be accounted for is change, 
 which Mr. Welton says it is, and which it is sometimes, then 
 causation does imply sequence in time, and time sequence is 
 an ' essential aspect ' of it, if by an essential aspect of it Mr. 
 Welton means a necessary factor in it. 
 
 But he has another reason for rejecting tim e seque nce as a 
 factor in causation. We cannot, he says, find the explanation 
 of change in preceding change ; for that would simply land 
 us in infinite regress ; by which he means that for each cause 
 we must find a preceding cause, and so ad hifijiitum. I do 
 not see the necessity. In following the chain of causes back- 
 ward we can stop where we please, and we usually have a good 
 reason for stopping at a certain point ; but supposing that 
 time sequence in causation does land us in infinite regress, 
 why not ? There is nothing inconsistent with our knowledge 
 of the universe in supposing that the causes of any change go 
 back to an infinity of past time. Infinite regress is no argu- 
 ment against the time element in causation. Mr. Welton 
 might as well say that the explanation of night and day 
 cannot be found in the rotation of the earth, for that would 
 simply land us in a movable earth. No doubt it would, and 
 what then ? 
 
 Instead of sequence in time, Mr. Welton presents us with 
 contiguity in s^^ace as the necessary element, or, as he calls it, 
 tlie essential aspect, of causation ; for, he says, it is only under 
 the form of space that we can rationalise our experience of 
 the influence of bodies on each other. I must confess I cannot 
 fathom this cryptic reason. I do not know what the form of 
 space is, nor do I know how to rationalise an experience ; but 
 
i ' 
 
 14 
 
 ON CAUSATION. 
 
 SOME THEORIES OF CAUSATION. 
 
 15 
 
 \ if by essential Mr. Welton means necessary, and if by con- 
 tiguity he means contact, or even nearness in space, of an 
 acting body to a body acted on and consequently changing, 
 then I deny altogether that contiguity is essential to causation. 
 The instance that must at once occur to everyone is the action 
 of an astronomical primary in causing the motion of its satellite 
 to pursue a certain path. Mr. Welton sees this, and his way 
 out of the difficulty is a very extraordinary one. ' How,' he 
 says, ' can we conceive a causal influence exerted on an object 
 I distant in space from the agent; as e.g. that of the sun on 
 nhe planets ? In reply to this it must be said that in one very 
 true and important sense of its reality a body must be thought 
 to be where its influence is felt : the power of exerting influence 
 is one of its properties, and where, therefore, that power is felt 
 there the agent truly zs in this, the only applicable sense. Of 
 course in another sense of its reality— the sense in which 
 reality is identified with visible and tangible form and tangible 
 resistance — the body may be absent, but then that aspect of its 
 reality is, in this case, beside the mark.' If Mr. Welton 
 succeeds in deceiving himself by thus juggling with the word 
 reality, the abracadabra of the philosophy that is made in 
 Germany, I know not whether he is more to be envied or 
 pitied, but I am very sure that he will not deceive anyone else 
 who has any appreciation of the meaning of words. He 
 might as well say that the German Emperor is omnipresent 
 throughout Central Europe, for that is where his influence is 
 felt. He might as well say, when a drunken man gives his 
 companion a black eye, that in a very true and important 
 sense of its reality the drink is in the black eye, for that is 
 where its influence is felt. Of course, in another sense of its 
 reality the drink is absent from the eye, but then that aspect 
 of its reality is beside the mark on the eye. Mr. Welton is, I 
 am afraid, not so thoroughly Germanised as he tries to make 
 out. No truly Germanised philosopher would spell the word 
 Reality without the capital, which makes it so much more 
 imposing. It will not, however, impose upon anyone who 
 Jooks to the meaning of words. 
 
 Cause and effect, says Mr. Welton, are not successive, but 
 
 fi 
 
 simultaneous ; and to prove this he instances the fornnation of 
 water ' The cause of the formation of water is the combma- 
 tion in definite proportions of hydrogen and oxygen, but this 
 combination does not precede the formation of water, it ts that 
 formation ' Of course it is. He is juggling with words again 
 The formation of water is the same thing as the combination of 
 the two gases. That is a truism. It is an identical expression. 
 It is expressing the same thing in two different sets of words. 
 But the combination of oxygen and hydrogen, which is the 
 formation of water, is not the cause of that formation. The 
 cause of the formation, or of the combination, is first the mixture 
 of the -ases, and then the passage of a spark through them 
 And though the formation of water and the combination of 
 the gases is simultaneous, if, that is to say, a process can be 
 said to be simultaneous with itself, it is not simultaneous with 
 the mixing of the gases, nor is it simultaneous with the passage 
 of the spark. The mixing of the gases may precede the 
 combination by days, months, or years ; and though the com- 
 bination follows very rapidly on the passage of the spark, 
 they are not simultaneous. The combination begins in the 
 neighbourhood of the spark, and spreads throughout the 
 mixture, and this spreading takes time— a very short time, it 
 is true— but it takes time. The passage of the spark is ante- 
 cedent, the formation of water is consequent. 
 
 ' So it is,' says Mr. Welton, ' in every other case.' I agree to 
 this extent, that in every other case of change in which he makes 
 out that the cause is simultaneous with the effect, either what 
 he calls the cause is not the cause, or what he calls the effect 
 
 is not the effect. . 
 
 Mr Welton continues thus : 'We, then, arrive at this. Cause 
 and effect are not two but one.' So we advance from con- 
 tiguity in space to simultaneity in time, and from simultaneity 
 in time to identity ! How a body, supposing, as Mr. Welton 
 supposes, that a cause can be a body, can be contiguous in 
 space to itself, I do not know. I suppose that is another aspect 
 of its Reality. The question that arises in my mind is 
 whether the body is beside itself, or whether the person who 
 makes the assertion is beside himself. 
 
i6 
 
 ON CAUSATION. 
 
 A dropping of ink, says Mr. Welton, upon paper causes a- 
 blot, but the blot is there as soon as the contact of ink and 
 paper is made : it is that contact. But on his own showing it 
 ou^ht not to be. What he says is that cause and effect are one, 
 but the one he takes is neither cause nor effect. The cause is 
 the dropping oLlbfiankj^tJie effect is the blot. If cause aad 
 effect are one, the blot ought to be the dropping of the ink ;. 
 but Mr. Welton says it is not. It is the contact of the ink 
 with the paper. Such confusion and self-contradiction could 
 scarcely be found outside a book on logic. By a parity of 
 reasoning, when a man gets into bed, the getting into bed is 
 the man, or, if we take Mr. Welton's second alternative, which 
 he does not recognise as an alternative, but asserts as the same 
 thing, then the contact of the man with his bed is the man. It 
 ought not to be necessary to clear up such a very simple 
 matter, but seemingly it is necessary to point out that the blot 
 is not the contact of the ink with the paper : the blot is the 
 layer of ink in contact with the paper. And this layer of ink 
 on the paper does not appear simultaneously with the dropping 
 of the ink, it follows the dropping of the ink. The blot is not 
 on the paper until the dropping is arrested by the paper, is 
 
 over and done. 
 
 The fact to be accounted for, says Mr. Welton, is change \. 
 and the first example of causation that he adduces is that the 
 weight of the atmosphere is the cause of the height of the 
 mer'cury in the barometer. But the height of the mercury in 
 the barometer is not a change. Quite the contrary. The fact 
 to be accounted for in this case is not change, but the absence 
 of change. The fact to be accounted for is that the mercury 
 in the barometer does not sink. Perhaps the explanation is to 
 be found in another aspect of Reality, and it may be that in a 
 very true and important sense of its reality the absence of 
 change is the same as change. It is perhaps a Reality of 
 Identity, or an Identity in Reality, such as Mr. Bradley and Dr, 
 Bosanquet delight in. 
 
 'We, then, arrive at this,' says Mr. Welton, 'cause and 
 effect are not two, but one. That they are inseparable is indeed 
 recognised by the relativity of the terms themselves. A cause 
 
 SOME THEORIES OF CAUSATION. 
 
 17 
 
 without an effect, or an effect without a cause, is a contradiction 
 in terms and unthinkable.' So it is, but it is not more un- 
 thinkable than a cause which is identical with its effect, or an 
 effect which is identical with its cause. * But we must go 
 further,' says Mr. Welton, ' and say that in content they are 
 absolutely identical. It is only in form that they can be dis- 
 tinguished.' Here is the hoof — it is not a cloven hoof, but a 
 soliped — of Germanism again. Content is another of its 
 shibboleths or abracadabras. Content and form, reality and 
 identity, are its stock-in-trade, they are the four hoofs on which 
 it goes. Lug them in by head and shoulders, use them in any 
 sense or nonsense that you please, mix them up anyhow, and 
 you will pass for an up-to-date philosopher. Mr. Welton con- 
 fines his illustrations to cause and effect, but it seems a pity so 
 to limit the application of such a fertile philosophical principle, 
 and I rejoice in being able to extend it to other pairs of relatives. 
 Parent and offspring are not two but one. That they are 
 inseparable is indeed recognised by the very relativity of the 
 terms themselves. A parent without offspring, or an offspring 
 without a parent, is a contradiction in terms, and unthinkable. 
 But we must go further, and say that in content they arc abso- 
 lutely identical. It is only in forr?2 that they can be distinguished. 
 And the same is true of higher and lower, outside and inside, 
 murderer and victim, robber and robbed. In co?ttent they are 
 absolutely identical. It is only m form that they can be dis- 
 tinguished. How charming is divine philosophy ! 
 
 If cause and effect are not two, but one ; if they are abso- 
 lutely identical (I leave out content, for I do not know what the 
 content of a cause is, or how it can have any content. A cause 
 is not a box or a bag) ; if, I say, they are absolutely identical, 
 how idle it is to seek for causes or for effects ! The main 
 occupation of the whole human race, ever since it attained 
 the status of humanity, is founded on a chimaera. What is the 
 cause of the alternation of day and night ? That silly man, 
 Copernicus, thought he had discovered it. What is the cause 
 of the spout of blood from a severed artery? The stupid 
 Harvey thought he had discovered it. What is the cause of 
 the suppuration of wounds, of pysemia, of septicaemia ? The 
 
I ^ 
 
 ig ON CAUSATION. 
 
 foolish Lister pretended that he had discovered it. What is the 
 cause of malarial fever ? of earthquakes ? of Brown's success in 
 growing roses ? of Jones' failure to secure the hand of Miss 
 Robinson ? What is the cause of mimicry in animals ? What 
 makes the days warmer in summer than in winter ? 
 
 What makes the price of conn and Luddites rise ? 
 What fills the butchers' shops with large blue flies ? 
 
 And finally, what is the cause of philosophers writing nonsense? 
 Nothing could be clearer. Nothing could be plainer or more 
 manifes't. The chief, the most important, the most absorbing 
 occupation of mankind has always been the search for causes. 
 What folly ! The causes were under their noses all the time. 
 They saw the effects, and the effects are absolutely identical 
 
 with the causes. 
 
 Another recent writer on the subject is Prof. Karl Pearson, 
 whose Grammar of Science has achieved a popularity remark- 
 able for a work of the kind. It is disfigured by much uncouth 
 phraseology, and by the Papal infallibility that the author claims 
 for his own doctrines, which he attributes to a personified 
 science. On nearly every page he speaks of ' a routine of 
 experience,' a 'routine of sense impressions,' a 'routine of 
 perceptions.' These are his fundamental terms, but he never 
 defines them, and we are left to conjecture what he means by 
 them. Far on in the book he speaks of the routine of perceptions 
 as equivalent to ' the uniform order of phenomena,' and ' the 
 uniformity with which sequences of perception are repeated' •, 
 but whether this is another name for causation, or whether it is 
 merely our old familiar friend the Uniformity of Nature, we are 
 left in doubt. Even if he does mean the Uniformity of Nature, 
 we are no better off, for no two philosophers agree on what is 
 to be meant by the Uniformity of Nature. The only thing on 
 which they agree, and when they do agree their unanimity is 
 wonderful, is that Nature is not uniform. 
 
 Much of the authority that Prof. Pearson's Grammar of 
 Science has unquestionably achieved is due to his habit of 
 attributing his own opinions to a personified science, a trick 
 that enables him to pose as infallible, while adroitly avoid- 
 
 90ME THEORIES OF CAUSATION. 
 
 19 
 
 ing the appearance of arrogance that such a pose carries with 
 it. When he says that for science cause is meaningless, he 
 means that Prof. Pearson does not understand the meaning of 
 it • when he says that science can in no case demonstrate this 
 or that, he means that Prof. Pearson cannot demonstrate it ; 
 when he says that science can find no element of enforcement 
 in causation, he means that Prof. Pearson is too blind to see the 
 element of enforcement ; and so on. This is an adroit method 
 of imposing on the gullibility of his readers, for who, in these 
 * scientific ' days, would have the temerity to question the pro- 
 nouncements of science ? But I must confess to some surprise 
 that it has been so successful. I should have thought that it 
 might have occurred to some one that science in this sense is 
 only a name for a body of opinion ; a body of fluctuating 
 opinion, varying from time to time and from person to person, 
 so that what is science to-day was heresy yesterday, and will 
 be superstition to-morrow ; what is science to one is stupidit}^ 
 to another, and falsehood to a third. What is science to Prof. 
 Pearson, for instance, is nonsense to me. 
 
 Professor Pearson belongs to the school of Hume and IMill, 
 and with them denies that there is any ' enforcement ' of an 
 effect by its cause, or any necessary connection between them. 
 The cause is merely the antecedent, the effect merely the sub- 
 sequent. The one happens to follow the other, but there is no 
 reason or necessity why it should do so : they are in no vv^ay 
 connected ; but when we see repeated instances of the same 
 succession of events, we deludedly jump to the conclusion that 
 the predecessor is the cause of the successor. Almost as soon 
 as it was stated, Reid blew this doctrine sky high by adducing 
 the instance of night and day. Day always precedes night, and 
 night always follows day, but no one supposes that day is the 
 cause of night or that night is the effect of day. And why 
 not ? Manifestly because they are merely antecedent and 
 subsequent; because there is no power in day to produce night; 
 because there is no enforcement of night by day. Prof. 
 Pearson bases his repudiation of enforcement on practically 
 the same ground as Hume does, viz.^ that our notion of force is 
 purely imaginary, and has no counterpart in the world outside 
 
 f \ 
 
 -t^"—'- ~>'fe^^^- ^^■*AJy;^ 
 
20 
 
 ON CAUSATION. 
 
 SOME THEORIES OF CAUSATION. 
 
 21 
 
 I 
 
 • n 
 
 
 our imagination. In this he confuses, as Hume does, imaginar>r 
 with conceptual. Our concept of force, like all our concepts of 
 primitive things, such as motion; resistance, extension, duration,, 
 and so forth, is a generalisation from many experiences of 
 individual instances ; and if we are to discard the one because 
 it is conceptual, that is to say, a generalisation, then we must 
 discard the rest for the same reason. In that case our minds 
 are left blank, and reasoning is impossible for want of pabulum. 
 In contradiction to this doctrine it is enough to appeal to 
 universal experience. By cause we do not mean mere ante- 
 cedence, nor by effect do we mean mere succession. If we 
 did, we should accept day as the cause of night, and night as 
 the' effect of day. If we did, the old and notorious fallacy, 
 post hoc, ergo propter hoc, would be no fallacy : it would be an 
 unassailable truth ; yet the same logicians who declare in their 
 Chapters on Causation and Induction that causation is nothing 
 but sequence, declare in their Chapter on Fallacies that it is 
 fallacious to argue from post hoc to propter hoc. But no incon- 
 sistency or self-contradiction in a doctrine ever yet deterred 
 logicians from teaching it ; and no doubt they will continue to 
 teach this self-contradiction along with the rest, until the whole 
 silly pseudo-science is swept away, and goes to join Judicial 
 Astrology, Phrenology, and Humoral Pathology upon the 
 rubbish heap. In forming our idea of cause and of causa- 
 tion, the enforcement of the effect by the cause enters as an 
 inseparable and necessary element into the notion, and if that 
 element is extruded, that which appeared to be a cause is a 
 cause no longer. ' The necessity,' says Prof. Pearson, ' thus 
 lies in the nature of the thinking being, and not in the percep- 
 tions themselves ; thus it is conceivably a product of the per- 
 ceptive faculty.' How it can be a product of the perceptive 
 faculty and not be a percept or perceived ; how that can be per- 
 ceived which is purely imaginary, and has no sensory impression 
 as a basis or provocation to perception. Prof. Pearson does not 
 inform us. His psychology is as hazy as his notion of causation. 
 However, Prof Pearson goes with the crowd, and quotes as 
 from Mill the definition that causation is uniform antecedence ; 
 and this definition, says Prof Pearson, is perfectly in accord 
 
 with scientific concept — that is, with Prof. Pearson's concept. 
 It may be a good definition, but when Prof. Pearson says it is 
 John Stuart Mill's definition, he is mistaken. Among all of 
 Mill's many definitions of cause and causation this one is not 
 to be found. In this instance * science ' is at fault. 
 
 * For science,' that is, for Prof. Pearson, * cause, as origi- 
 nating or enforcing a particular sequence of perceptions, is 
 meaningless — we have no experience of anything which 
 originates or enforces something else.' The most obvious 
 answer to this is that it is not true. It contradicts the whole 
 experience of the whole human race. Every time we move a 
 thing from one place to another we demonstrate the falsity of 
 the assertion. The word ' originating ' is used equivocally. 
 A change in anything is originated when the change begins ; 
 that is, when the thing begins to change. But it seems from 
 the context that Prof. Pearson denies that change — the 
 sequence of perceptions, as he calls it — is then originated, 
 because it can always be traced to previous change, and there- 
 fore in this sense it is not 'originated.' This is an obvious 
 confusion. The particular change in the thing changing is 
 none the less originated, although it may be the effect of some 
 previous change in something else. What Prof. Pearson means 
 is that the total sequence of changes never originates, or, as I 
 should say, begins. It is the same difficulty that Mr. Welton ' 
 calls infinite regress, and which he takes as a conclusive argu- 
 ment against the time element in causation, while Prof. 
 Pearson takes it, with equal inconsequence, as an argument 
 against causation itself In so far as it is an argument at all, 
 it is as much an argument against the existence of change as 
 against the existence of causation, or of a time element in 
 causation ; but it is no argument against either. Grant that 
 change generally, apart from individual changes, never begins, 
 but can be traced back until it is lost in the infinity of past 
 time, still that is no argument against causation. It merely 
 shows that every cause has itself a cause ; and so far from 
 abolishincr causation, it renders causation more than ever 
 certain, and necessary, and universal. But I need not labour 
 the argument, for Prof. Pearson has himself refuted it. On 
 
 i - * . ' iwi j %'i 
 
h t!i 
 
 W 11 
 
 ■!'. 
 
 22 
 
 ON CAUSATION. 
 
 SOME THEORIES OF CAUSATION. 
 
 p. 9 he says, * the man who has accustomed himself to 
 marshal facts, to examine their complex mutual relations, and 
 predict upon the result of this examination inevitable sequences.' 
 Here he is evidently referring to himself, and if a sequence is 
 inevitable, it is enforced ; it is necessary ; it is not the mere 
 casual sequence that he says causation is. To say that a 
 sequence is inevitable, and to say that it is enforced, is to say 
 the same thing in different words. 
 
 However, Prof. Pearson sees what Hume did not appear ta 
 see, and what Mill certainly did not sec, that if we take away 
 from causation the element of enforcement, or of power in the 
 cause to produce the effect, causation vanishes with it, and the 
 only logical attitude is to deny altogether that there is any 
 such thing as causation. To this necessary result of their 
 teaching, Hume and Mill were blind ; but Prof. Pearson sees 
 it, and Mr. Bertrand Russell sees it, though they both see it 
 only in transitory and occasional glimpses, and for the most 
 part lose sight of it. They both deny that causation exists, 
 and thev both define what it is — not what it means, but what 
 it is. Prof. Pearson asserts that the ' category of cause and 
 effect ' is a fetish ; that the law of causation is a figment ; that 
 no experience demonstrates causation ; that for science, that is 
 to say, for him, cause is meaningless ; and he asks whether 
 causation is anything but a conceptual limit to experience, a 
 cryptic question that, for my own part, I am unable to answer 
 until I know what it means. Having said this, he says he will 
 show how antecedents are true scientific causes ; he states the 
 law (which, by the way, is nonsense, as he himself in another 
 place shows, though he endorses the law) that the same set of 
 causes is always accompanied by the same effects; he says that 
 no phenomenon has only one cause ; and he even goes so far 
 as to say we fail to comprehend a world to which the concep- 
 tion of cause and effect would not apply. How he reconciles 
 these contradictions in his own mind I shall not specullate, but 
 I am very sure that he will not succeed in reconciling them in 
 the mind of anyone else, except, perhaps, in the minds of Mr. 
 Bradley and his followers or in the mind of a German of the 
 school of Hegel. 
 
 I\ 
 
 23 
 
 . The most popular doctrine of Prof. Pearson's is his distinc- 
 tion between kow and wk}^, a distinction which is either the 
 cause, or the chief effect, of his theory of causation. He denies 
 that we can ever discover w/i}' a thing happens, or explain it ; 
 and limits our powers to saying kow it happens, or describing 
 it In this he is demonstrably wrong. It is often as impos- 
 sible to describe how things happen as to explain why they 
 happen : it is often as easy to explain why they happen as to 
 describe how they happen. The fact is that both how and 
 w/iy are equivocal words, having more than one meaning ; but 
 whichever meaning we take, what I have said is true. Horn 
 may mean in what manner, or it may mean by what means. 
 iV/ty may mean for what purpose, or it may mean in obedience 
 to what law, in conformity with what rule. In any of the four 
 cases the answer may be easy, or difficult, or impossible ; and as 
 to either kow or w/iy, we may be able to answer one meaning 
 and not the other. If, for instance, we ask how, in the sense 
 of by what means, gravity acts, we cannot answer. It is im- 
 possible to imagine by what means a body can attract another 
 through an immeasurably great distance. It is only when we 
 ask how, in the sense of in what manner, gravity acts that we are 
 able to answer that it acts inversely as the square of the dis- 
 tance. If we ask why, in the sense of with what purpose, the sap 
 circulates in the tree, we have no difficulty in explaining that 
 it is that the sap may be aerated, the tree nourished, its life 
 maintained, and its growth increased. It is only when we ask 
 why, in the sense of in conformity with what law, the sap cir- 
 culates, that we are unable to answer. We do not know 
 whether it is capillary attraction or what it is. 
 
 A good example of the manner in which Prof Pearson poses 
 as a superior being is the advice he gives to his readers, 
 to analyse what is meant by such statements as that the 
 law of gravitation causes bodies to fall to the earth. The 
 law, he says, really describes how bodies do fall. Of course 
 it does ; but before Prof Pearson gave this advice to his 
 readers, he should have shown some evidence that some one 
 besides himself had ever said such a silly thing. As far as I 
 know, no one has ever pretended that the law of gravitation 
 
 f 
 
 I \i 
 
 *<B-wyrsa- ,wrir.<;..T<g^^ 
 
: 
 
 I ^'i 
 
 II! 
 
 24 
 
 ON CAUSATION. 
 
 causes bodies to fall to the earth ; but if anyone should say 
 that the fact of gravitation — the fact that they attract each 
 other — causes bodies to fall to the earth, he would say what is 
 exactly and punctually true. The law of gravitation describes 
 how bodies fall : the fact of gravitation explains why they fall ; 
 and the explanation is as good and as valid as the description. 
 As far as I know, Prof Pearson never answers the actual argu- 
 ments of real antagonists ; and if he prefers the easier task of 
 answering silly arguments that he puts into the mouth of an 
 imaginary antagonist, then, whatever we may think of his 
 courage and sincerity, we cannot question his wisdom. 
 
 Mr. Bertrand Russell follows Professor Pearson in denying 
 the existence of causes. He says there are no such things. 
 He wants the word abolished, and regards the law of causation, 
 or, as he calls it, of causality, as a relic of a bygone age. To 
 prove this contention he selects from Baldwin's Dictionary the 
 definitions given therein of Causality, of the notion of Cause 
 and Effect, and so forth ; he takes one of Mill's definitions of 
 Causation, and an expression of Bergson's, and analyses them 
 all destructively. 
 
 All these expressions assume, and Mr. Russell repeatedly in 
 his own expressions assumes, that repetition of instances is 
 necessary before we can identify causation, and I think it is 
 not too much to say that he regards recurrence or repetition as 
 a necessary element, either in causation itself, or in our idea of 
 causation. The definitions that he quotes all countenance 
 this supposition. They run : Whenever the cause ceases to 
 exist ; whenever the effect comes into existence ; the Law of 
 Causation is invariability of succession ; the same causes pro- 
 duce the same effects ; a certain phenomenon will not fail to 
 recur \ and so on ; and he himself says that an ' event ' in the 
 statement of the law is obviously intended to be something 
 that is likely to recur ; and he makes this the basis of his 
 criticism. Criticism directed against such notions of causation, 
 however destructive of them it may be, is not relevant against 
 a definition of cause or of causation into which the element ot 
 repetition or recurrence does not enter. To me, repetition or 
 recurrence is not a necessary ingredient, either of causation 
 
 SOME THEORIES OF CAUSATION. 
 
 25 
 
 itself, or of my idea of causation, and therefore against my 
 definition Mr. Russell's attack is not directed ; but even acrainst 
 the definitions that he does attack, erroneous as I believe them 
 to be, his criticisms do not appear to me to be destructive, or 
 even damaging. 
 
 Thus he confutes the succession in time of cause and effect, 
 or that antecedence and consequence on which Mill and his 
 school lay so much stress : * No two instants are contiguous, 
 since the time series is compact.' I cannot see that the 
 conclusion follows from the premiss. It seems to me that the 
 more compact the time series, the more closely contiguous must 
 be its instants. If Mr. Russell means that time is continuous, 
 and not made up of instants separated from one another by 
 intervals that are not time, or in which there is no time, I 
 should agree with him ; but it is only in such an interrupted 
 time series that the instants would not be contiguous. An 
 instant, like an hour or a day, is a portion of time arbitrarily 
 divided by an imaginary limit from that which precedes and 
 that which follows, with both of which it is continuous or 
 contiguous. But if^Mrr Russell is right, and no two instants 
 are contiguous, and if serial contiguity in time between cause 
 and effect is necessary to causation, then this settles the 
 question : then causation is impossible, and Mr. Russell's 
 further argument is redundant, supererogatory, and unneces- 
 sary. But he docs not think so, for he goes on : ' Hence 
 either the cause or the effect or both must, if the definition 
 [Baldwin's definition of Cause and PZffect] is correct, endure 
 for a finite time . . .' I asrree that both the cause and the 
 effect must endure for a finitelTme, tlioudi I do not see how 
 this follows from the supposition that no two instants of time 
 are contiguous. * But then we are faced with a dilemma : if 
 the cause is a process involving change within itself, we shall 
 require (if causality is universal) causal relations between its 
 earlier and later parts ; moreover, it would seem that only the 
 later parts can be relevant to the effect, since the earh'er parts 
 are not contiguous to the effect. Thus v/e shall be led to 
 diminish the duration of the cause without limit, and however 
 much we may diminish it, there will still remain an earlier part 
 
 fj 
 
26 
 
 ON CAUSATION. 
 
 SOME THEORIES OF CAUSATION. 
 
 27 
 
 which might be altered without altering the effect, so that the 
 true cause, as defined, will not have been reached.' This ma/ 
 or may not be an effective criticism of a definition of cause 
 and effect that defines them as contiguous in time, but to me 
 it is too much like the old problem of Achilles and the tortoise 
 to be convincing. Zeno proved quite satisfactorily that Achilles 
 could never overtake the tortoise— only he did ; and Mr. 
 Russell proves less satisfactorily that there is no such thing as 
 causation, but yet he, in common with the rest of us, always 
 acts on the supposition that there is such a thing, and, so 
 actincT he never meets with experience that contradicts the 
 supposition ; and this is for us the conclusive and inescapable 
 proof, first that the supposition is true, and second that Mr. 
 Russell is convinced that it is true. 
 
 He goes on to show that if cause and effect are not con- 
 tiguous in time, then there must be an interval between them ; 
 and ' since there are no infinitesimal time intervals ' this lapse 
 of time must be finite. But if there is a finite interval of time 
 between cause and effect, something may happen ^ that 
 interval to prevent the effect following the cause. It is all 
 very pretty word spinning, and for all I know it may apply 
 to the kind of ' causality ' that occurs in the moon, or in a 
 universe of one dimension, but it has no relation whatever to 
 causation as it is known on this earth. Mr. Russell assumes 
 that effect follows cause in the sense of what carpenters call a 
 butt joint, in the senseJ±LaLL.the^e£CecL.jd(;^aot begin until the 
 cause has ceased to act. That may be what happens in some 
 other universe, but it is not what happens here. What happens 
 here is quite different, as Mr. Russell might have known if he 
 had considered an actual case of causation instead of specu- 
 lating with .1, .2, . . • ^n, and t^, t^, . . • t„ and r. When, 
 for instance, a man pushes a trolley, he causes it to move. The 
 pushing is the cause, the movement is the effect. But the 
 effect is not postponed until the cause has ceased to act. The 
 effect does not come suddenly into existence at an instant 
 contiguous to the cessation of the cause. The effect begins as 
 soon or almost as soon, as the cause begins ; thereafter, 
 cause and effect, the pushing and the movement, accom- 
 
 pany one another, and proceed contemporaneously for a 
 certain time ; and at length, when the cause ceases, the 
 effect ceases. Cause is contiguous to effect in this case, 
 not end to end, but side by side for the greater portion of their 
 duration. The joint is not a butt joint but a fish joint ; 
 and all Mr. Bertrand Russell's pretty word spinning goes for 
 nothing. 
 
 His own statement of ' causality,' cannot, he says, be put 
 accurately in non-mathematical language ; the nearest approach 
 would be as follows : * There is a constant relation between 
 the state of the universe at any instant, and the rate of change 
 at which any part of the universe is changing at that instant, 
 such that the rate of change in the rate of change is determinate 
 when the state of the universe is given.' It is with diffidence 
 that I comment on this mysterious formula, but it seems to 
 me clear that if anything can be discovered by its means, it is 
 not the cause of a change, but the rate at which a change takes 
 place, or rather the rate of change in a rate of change ; which 
 may be a desirable thing to know, but by no perversity of 
 ingenuity can be twisted or tortured into a cause. But sup- 
 pose the impossible to be true, and suppose that no cause of 
 anything can be discovered or assigned unless and until the 
 state of the whole universe is known ; then it is clear that no 
 cause of anything ever has been discovered or ever can be dis- 
 covered, for we can never know the state of the whole universe. 
 But in fact many causes of many things are known, and more 
 are being discovered every day. I know, for instance, that 
 pushing a trolley is a cause of the movement of that trolley. 
 I know that reading such disquisitions as Mr. Welton's, Pro- 
 fessor Pearson's, and Mr. Bertrand Russell's, are among the 
 causes of the estimate I have formed of philosophers. Mr. 
 Bertrand Russell may be a great mathematician, Professor 
 Pearson a great statistician, and Mr. Welton a great authority 
 on education ; but there is a certain proverb about the cobbler 
 and his last that I would commend to the notice of all three. 
 It may be that I must determine the state of this earth, and 
 of everything upon it, in it, and around it ; of all its continents, 
 seas, rrvers, lakes, and islands ; of all its minerals, from the coal 
 
 ■111 
 
 
 
 t 
 
28 
 
 ON CAUSATION. 
 
 SOME THEORIES OF CAUSATION. 
 
 29 
 
 i'- 
 
 I i 
 
 i 
 
 to the diamond ; of all its vegetables, from the bacillus to the 
 oak and the orchid ; of all its animals, from the spirochaste to 
 the whale • of all its human inhabitants, from the Bushman to 
 Mr Russell himself; and beyond this, of all the solar system 
 with its planets, planetary streams, satellites, and comets ; of 
 all the stars which we call fixed, with their temperatures, posi- 
 tions, sizes, movements, and chemical composition— it may be 
 that I must know all these things with accuracy before 1 can 
 discover what it is that is tickling my nose ; but for my own 
 part I don't believe it. In fact, I do not know all these things, 
 I know only some of them, and I have already discovered the 
 cause No doubt Mr. Bertrand Russell knows best, but my 
 own private belief is that though mathematics cannot err, 
 
 mathematicians can. , . 
 
 The last view of cairsation that I shall examine is Ur. 
 McTacrcart's, which I select because it is the latest to be pub- 
 lishedrhaving appeared only last July. Like Mr. Russell, he . 
 calls it causality, which, to be sure, is a more imposing term ; 
 but sometimes he fails to maintain the philosophical nomen- 
 clature and drops back into common causation. Por thorough 
 mystification, and for the most extreme departure from plain 
 meanin- and common sense, Dr. McTaggart runs Mr. Bertrand 
 Russell very hard. According to Dr. McTaggart, ' causation 
 is a relation of implication between existent realities— or to 
 put it more precisely, between existent substances.' This does 
 not on the face of it afford us much help in understanding what 
 causation is, but unlike most philosophers, Dr. McTaggart defines 
 his terms and for this one cannot be sufficiently grateful to him, 
 not only on general grounds, but also for the surprising meanings 
 that he shows lurk unsuspected in the mast ordinary terms. A 
 substance, for instance, according to Dr. McTaggart, is anything 
 that can have qualities and relations ; so that, for instance, the 
 battle of Waterloo and a flash of lightning are substances m the 
 McTa-crartian sense. This is a bit startling, but definitions are 
 so rarein philosophy that we must be thankful for any we can 
 get even if they leave us more mystified than before. The 
 battle of Waterloo is presumably not only a substance but also 
 an existing substance in the McTaggartian world, though to the 
 
 rest of us it ceased to exist a hundred years ago. Causation, 
 then, is a relation of implication between such existing sub- 
 stances as the battle of Waterloo and a flash of lightning ; but 
 what is a relation of implication ? Here again Dr. McTaggart 
 comes to the rescue with a definition. A relation of implica- 
 tion is a relation between two propositions, P and Q. such that 
 P implies Q, when, if I know P to be true, I am justified by 
 that alone in asserting that Q is true, and, if I know O to be 
 false, I am justified by that alone in asserting P to be false. 
 
 So far, so good, but still we are a long way from attaining a 
 clear idea of causation ; but Dr. McTaggart is not done yet. 
 * Strictly speaking,' he says, ' implication is a relation between 
 propositions or truths [is a proposition, then, necessarily true ?] 
 and not between events. But it is convenient to extend our 
 use of it, so as to say that if one proposition implies another, 
 then the event asserted in the first implies the event asserted 
 in the second [but how if neither of them asserts an event ?]. 
 It is in this sense that the cause implies the effect' — causes it, 
 in fact. The jump from propositions to events is a bit start- 
 ling to those who are not accustomed to the proper meaning of 
 realities and substances, but interpreting these expressions to 
 the best of my ability, I gather that when we say the cause 
 implies the effect, we mean that if the cause is true the effect 
 is true, and if the effect is false the cause is false. But what 
 on earth is the meaning of a cause or an effect being true or 
 false ? It does not appear that by a true cause Dr. McTaggart 
 means the causa vera of the Schools, but what he does mean I 
 cannot conjecture ; and supposing this difficulty to be cleared 
 up, what is the meaning of a false effect? Is it an effect that 
 never happens ? or is it an effect that is wrongly attributed 
 to a certain cause? or is it something else? It is to be re- 
 gretted that Dr. McTaggart has not supplemented his definitions 
 with others, explaining the meaning of these terms. In this 
 difficulty the only practicable expedient is to clothe the expres- 
 sion in circumstances — to apply the general rule to an individual 
 case. 
 
 I take, therefore, two propositions, Brutus killed Ccesar, and 
 Brutus and CcBsar were contejuporaries^ which stand in a rela- 
 
 
 
 i 
 
I i 
 
 III 
 
 f 
 
 
 30 
 
 ON CAUSATION. 
 
 tion of implication ; for if P, or Brutus k.Ued Caesar is true, 
 then we are justified by that alone in asserting the truth of y, 
 that they were contemporaries ; and if Q, or Brutus and Caesar 
 were contemporaries, is false, then we are justified by that alone 
 in asserting the falsity of P. that Brutus killed Caesar. Th.s 
 specimen fulfils all Dr. McTaggarfs conditions The relation 
 is undoubtedly a relation of implication ; and the k.lhng of 
 Cssar by Brutus is a substance, for it can have qualities, such 
 as treachery, unexpectedness, rapidity, and so forth. It does 
 not seem to me to be an existing substance, it ,s true but rt is 
 as much an existing substance as the battle of Waterloo. The 
 contemporaneousness of Brutus and Caesar is a relation, and 
 therefore this also is a substance, and to the same extent as 
 the other is an existing substance. All the conditions bemg 
 satisfied, we may therefore predicate a relation of causation 
 between these two existing substances ; but now our difficulties 
 be-in for I cannot understand whether the fact that Brutus 
 kilted Caisar caused them to live at the same time, or whether 
 the fact that they were contemporaries caused Brutus to ki 
 Cssar If the latter, why did not all his other contemporaries kill 
 Cssar' and why did not Cssar kill Brutus? If the former, 
 what caused Brutus and Cssar to have so many other contem- 
 noraries ? I have puzzled over these problems till my brain 
 is almost turned, and I am no nearer a solution, and am 
 obliged to give them up. I doubt whether anyone_ but Dr. 
 Mcf a-art could solve them ; and a method which is useless 
 in the'^hands of everyone but its inventor is never likely to 
 
 become popular. 
 
 Dr McTaggart arrives at certain other conclusions that are 
 interesting He decides that there is no reason to believe ' that 
 a cause exerts an activity or an effect.' What is meant by a 
 cause exerting an effect I do not know, and another definition 
 would be useful here ; buf if Dr. McTaggart means that a 
 cause does not produce an effect, then I respectfully submit 
 that it is not a cause. Moreover, if a cause does not exert an 
 activity it is only because it is an activity, or more properly an 
 action. Cause and activity can no more be divorced than heat 
 and motion, or solidity and resistance. Dr. McTaggart decides 
 
 I 
 
 11 , ; 
 
 SOME THEORIES OF CAUSATION. 
 
 31 
 
 that cause and effect are not identical, a discovery that will not, 
 I think, astonish anyone but Mr. Welton ; that the effect is not 
 necessarily subsequent to the cause, and, indeed, he is not quite 
 sure that the effect may not sometimes come first, and the cause 
 follow after it ; and at last he declares, in despair it seems to me, 
 that though cause and effect are not identical, yet there is no 
 means of knowing which is which, or at any rate, there is no clear 
 distinction between them ; and therefore, though we may speak 
 of causal relations as existing between two terms, yet we ought 
 not to speak of one of those terms as cause, and of the other 
 as . effect. I think we may legitimately complain that Dr. 
 McTaggart does not tell us what we ought to call them. 
 Ought we to call them both X, or the one X and the other Y ? 
 Ought we to call the one beef, and the other Yorkshire pudding? 
 Or ought we to call the one petticoat and the other trousers ? 
 Dr. McTaggart gives us no guidance, and the reader must 
 choose for himself 
 
 The lecture in which Dr. McTaggart expounded these views 
 was delivered at Newnham College, presumably to an audience 
 of young women, and I trust he developed to them his views of 
 the impropriety of naming the related terms when describing 
 relations. He convinced them, I trust, that it is convenient to 
 speak of the relation of marriage, but inconvenient (and per- 
 haps improper), to speak of bride and bridegroom, or of husband 
 and wife ; that it is convenient to speak of parentage, but not 
 of parents or of children ; that it is convenient to speak of the 
 relation of cousinhood, but that they should never allow them- 
 selves to use such expressions as Harry or Mary. 
 
 In concluding this survey of certain theories of causation, I 
 beg to assure the reader that they are stated with accuracy, in 
 the ipsissinia vet'ba of their authors. They are not garbled, 
 altered, or modified in any way. Everything material has been 
 stated, and nothing has been mis-stated. They are not the 
 theories of Laputa, nor are they the ravings of Bedlam. They 
 are not jokes, nor are they intended for caricatures. They are 
 the serious attempts of philosophers of position and repute to 
 solve a simple problem that every ploughman and artizan, 
 though he may not be able to put his solution into words, has 
 
 * >i 
 
I 
 
 . Ii 
 
 ¥ -i 
 
 32 
 
 ON CAUSATION. 
 
 solved in practice for ages. Carlyle, in his genial-Way, charac- 
 terised a certain philosophy as pig-philosophy. I should qualify 
 the philosophers' treatment of causation with the name of 
 another domestic animal, unlike a pig in that its hoofs are not 
 cloven, nor its long ears drooping. 
 
 My view is that when we common people who are not 
 philosophers speak of causation, and, as we do in spite of Dr. 
 McTaggart's warning, of cause and of effect, we attach to these 
 words very positive and downright meanings. We feel and 
 know that in seeking for causes, in noting effects, in trying to 
 identify causation, endeavours that occupy the greater part of 
 our lives, we are not pursuing an ignis fatuus, but we are domg 
 that without which it is impossible for men to live profitably, 
 nay, it is impossible for them to live at all. If we have no 
 very clear notion of what we mean by cause, effect, and causa- 
 tion, this want of precision, which is largely due to the fog in 
 which they have been enveloped by philosophers, does not 
 interfere with our practical pursuit of them. If the plain man, 
 immersed in practical affairs, cannot precisely define what he 
 means by these terms, neither can he define precisely the 
 meanin- of capital, of labour, of rent, of interest, of life, of 
 death, of disease, or of hundreds of other terms that he uses m 
 his daily work, and that represent things of the utmost moment 
 to his welfare, his happiness, and his life. But because he can- 
 not define them, is he therefore to say that the thmgs they \ 
 stand for have no existence ? that they are empty words, that 
 represent nothing outside his own misguided imagination? ^ 
 This is the conclusion to which philosophers are driven by their/ 
 inability to define cause and effect. On the same ground, and 
 for the same reason, they should deny the existence of life and 
 death. This is the result of living in the mOon, and ignoring 
 all the efforts of the toiling millions of mankind. The only 
 way to discover the meaning of cause and effect is— to find 
 out what men mean by them ; and we shall not do this by 
 word-spinning ; by pretending a difference between connection 
 and conjunction ; by denying the existence of force ; by con- 
 tradicting ourselves twenty times over ; by calling sequence 
 simultaneity, and simultaneity identity ; by posing oracularly 
 
 \ 
 
 '*■ l'^ 
 
 SOME THEORIES OF CAUSATION. 
 
 33 
 
 as embodied science ; by ingenious puzzles about the divisi- 
 bility or indivisibility of time ; or by defining that which is easy 
 to understand by that which is impossible to understand. No. 
 To find the meaning of cause and effect, and of cognate terms, 
 . we must come out of the moon, and go, not merely into the 
 laboratory and the observatory, but into the home, the kitchen,' 
 the workshop, the factory, the garden, the field, and all the busy 
 haunts in which men and women are all day long seeking 
 •causes, studying effects, and watching the course of causation. 
 
 Summary, 
 
 Hume's denial that force or power exists, and that there is 
 any connection between cause and effect, is based on faulty 
 reasoning, and in the light of modern psychology cannot be 
 sustained. He himself so defines causation as to assert a 
 necessary connection between cause and effect. 
 
 Mill's treatment of the subject is confused, waverino- and 
 contradictory. He defines cause and causation many times 
 over, and never adheres to one definition. Generally, he follows 
 Hume in identifying causation with invariable antecedence and 
 sequence, but he does not adhere to this, nor to any, opinion. 
 
 Mr. Welton denies that antecedence or sequence, or any time 
 element, enters into causation. In place of the time element 
 he asserts that contiguity in space is necessary to causation. 
 From this he argues that cause and effect are not in sequence, 
 but are simultaneous ; and at length decides that they are 
 identical. His reasoning is inconsequent, and his conclusions 
 are opposed to universal experience and to common sense. 
 
 Professor Pearson follows Hume and Mill in denying any 
 enforcement of the effect by the cause, and in regarding causa- 
 tion as invariable sequence. He also denies the occurrence of 
 causation, and says it is meaningless ; nevertheless, he quotes 
 with approval the law of causation, and asserts that some 
 sequences are inevitable. His treatment of the subject is as 
 self-contradictory as that of Hume and Mill. 
 
 Mr. Bertrand Russell, like Prof Pearson, denies the existence 
 of causation, and like him formulates a law of causation, which 
 
 3 
 
\ 
 
 Eft 
 
 p 
 
 ,. I. 
 
 hi'i 
 
 !! 
 I' i 
 
 1 ' 
 
 34 
 
 ON CAUSATION. 
 
 1 
 
 is not a law of causation. It is so expressed as to require, 
 before we can determine what Mr. Russell calls the cause, 
 which is in fact not the cause, of anything, a knowledge of the 
 
 whole universe. 
 
 Dr. McTaggart defines causation as a relation of implication 
 between existing substances. Application of the definition to 
 a test case show5 that the definition is absurd, and affords no 
 guidance in practice.^ 
 
 In conclusion, it is suggested that the inability of philoso- 
 phers to define causation in consistent and intelligible terms 
 argues, not that causation is imaginary, but that philosophers 
 are incompetent. 
 
 * Nevertheless, a leader of the Germanised school of philosophers refers to Dr. 
 McTacraart's essay in the following terms: "The greater part of what he says 
 pos'^es'ses as one would expect from him, an almost convmcmg lucidity and 
 vraisemblance." Lucidity and vraisemblance ! Well, well! And convincing' 
 Heavens ! 
 
 t 
 
 CHAPTER 11. 
 EFFECT, REASON, RESULT, CAUSE. 
 
 The subject we are about to examine is the relation of 
 causation, and a relation comprises three things — the two 
 terms, and the link that relates them, and unites them in a 
 relation. The link is usually called a relation, which thus 
 becomes an ambiguous term, standing both for the link, and 
 for the triple whole of term — link — term. I have therefore, in 
 my New Logic, called the link the ratio. Mr. Bertrand Russell, 
 in a recent publication, calls it the relating relation, which is 
 possibly a better term, but is at any rate longer. The terms of 
 the relation we are about to examine are Cause and Effect, and 
 the ratio or link which binds them together and unites them in 
 a relation is Causation or Effectuation, according to the point 
 of view from which we regard it. It will be convenient to 
 begin our examination with the terms, and we may select 
 for this purpose either term we please. I shall begin with 
 effect. 
 
 The first thing, then, to settle is What is an effect ? What 
 do we mean, what do we think of, what have we in our minds, 
 when we use the term effect ? I think it is indisputable that 
 the idea of effect is inseparably connected with the idea of 
 change. Changes may be contemplated in and by themselves,! 
 as changes and no more; and this is how we contemplate' 
 changes to which we are well accustomed, such as the change 
 from day to night, and from night to day, the change from rain 
 
 
 ■it. 
 
 V 
 
36 
 
 ON CAUSATION. 
 
 EFFECT, REASON, RESULT, CAUSE. 
 
 37 
 
 II 
 
 I 
 
 I' ,f 
 
 I 
 
 to sunshine, and from sunshine to rain, the changes in the face 
 of the sky, the growth of herbage, the change from heat to cold 
 and from cold to heat, and all the customary changes of Nature. 
 These changes we may, and usually do, contemplate merely as 
 changes, without feeling any compulsion or need to regard them 
 as effects also, or to look behind them for their causes. But then 
 these changes are, in a sense, not changes to us. They are parts 
 of a routine, a changing routine, but a routine whose changes are 
 customary, and part of the routine ; a routine that, as a routine, 
 does not change, or changes but little. In such changes the 
 change to us is minimised, and the greater change would be if 
 the regular routine should cease to change. The changes that 
 are changes to us, that impress us as changes, are not the 
 regular customary changes of the routine, but the breaks in the 
 routine. But any change that impresses us as change, any 
 break in our customary routine of changes, especially if it is 
 rapid, and more especially if it 'is sudden, carries the mind 
 irresistibly to the notion of cause, and impresses us as an effect. 
 In such cases change is identified with effect, or, if not iden- 
 tified, is inevitably associated with effect. It is true that in 
 contemplation we can separate them. We can contemplate a 
 change either as change pure and simple, or as effect ; but 
 though separable in contemplation, in occurrence they are 
 inseparable. Just so we may contemplate gold without taking 
 into account its specific gravity, or we may contemplate it with 
 reference to its specific gravity ; but whether we choose so to 
 contemplate it or not, we know that its specific gravity is 
 inseparable from it. Whether we regard a change as simply a 
 change, or whether we regard it also as an effect, or whether 
 we regard it primarily as an effect, depends on the way we 
 choose to contemplate it. How close is the association between 
 change and effect is conspicuously displayed in the case of an 
 unaccustomed noise. When we hear a noise, especially a 
 sudden and loud noise, to which we are unaccustomed, the 
 natural and inevitable reaction is What's that ! And in putting 
 to ourselves this question, we do not mean, as the form of the 
 question seems to imply, What is the nature of that noise ? 
 That we already know. Our meaning is What is the cajisfi of 
 
 that noise ? Instantly and inevitably the mind passes from 
 changeloTcauseT^and regards the change as an effect ; and so 
 it is with every change to which we are unaccustomed, that is, 
 with every change that impresses us as change. 
 
 On the other hand, we do not, except in special cases that 
 will be examined directly— we do not seek for a cause for 
 things remaining unchanged, or regard want of change as an 
 effect. If, upon waking in the morning, or on entering a room, 
 we find the position of the furniture and all the other objects 
 the same as when we last saw them, we do not look upon their 
 unchanged position as the effect of anything, or seek for a 
 cause for it. When we come home after an absence, and find 
 the house, the trees, the bushes, the lake, and the distant hills, 
 all as we left them, we do not associate this want of change 
 with causation, nor do we regard it as an effect. It needs no 
 accounting for, no attribution of cause. 
 
 This is the general rule.. Every change maybe contemplated 
 as an effect, and will be so' contemplated in proportion as it is 
 unusual, for unusualness is what logicians would call the essence 
 of change ; that is to say, it is the element in change that 
 attracts our attention, and impresses us. It is what to us 
 constitutes change. A change that happens continually soon 
 ceases to be contemplated as change. It becomes to us a 
 continuity, and the change to us is when it stops— when the 
 clack of the mill ceases, when the roar of the streets subsides, 
 when the train arrives at the terminus. But if we choose so to 
 regard it, every change is an effect. 
 
 It does not follow, however, tha^^every effect is a change. 
 As a rule, no cause is"assumed for the want o"? change, or for 
 things remaining the same ; but this rule has very important 
 exceptions, constituted by the circumstances we have just 
 considered. There are cases in which we do assume a cause 
 for the retention by a thing of its state unchanging, cases in 
 which we regard the absence of change as^an^effect^-^There are 
 
 two such cases. 
 
 When a change is customary, and yet does not take place, 
 we assume that the absence of change is the effect of some 
 cause. The weather, for instance, in this country changes so 
 
 ' 1 
 
 ' 
 
 1H 
 
 !i ^ 
 
38 
 
 ON CAUSATION. 
 
 i: 
 [I ; 
 
 111 
 
 J 
 
 i\ 
 
 frequently, and change in the weather is become so much a 
 part of our customary routine, that when a change in the 
 weather takes place, we forget to regard it as an effect ; but 
 should the weather remain uninterruptedly stormy, or dry, or 
 wet, for six months together, we. should at length be driven to 
 assume a cause for this want of change, for the want of change 
 would be itself a change in the routine to which we are 
 accustomed. 
 
 The second case is when we know of forces in operation 
 tending to produce a change which yet" does not take place. In 
 such a case, if our attention is called fo the operation of such 
 forces, we inevitably assume a counter-cause for things remain- 
 ing unchanged, and regard this want of change, or unchange, 
 as an effect. If we pull the handle of a drawer, and the drawer 
 yields and opens, we regard the change in the position of the 
 drawer as the effect of the pull ; but if we make no attempt to 
 open the drawer, we do not regard its remaining closed as the 
 effect of anything. As there is no change, and nothing tending 
 to produce change, there is no effect. But if we pull the drawer 
 and it does not move, then the want of change, in circumstances 
 tending to produce change, at once becomes an effect, and 
 carries the mind irresistibly to the necessity of a cause. When 
 the mercury in a cup remains level, we do not regard the main- 
 tenance of the level as an effect, for it is no change from the 
 customary behaviour of mercury ; but when the mercury in a 
 Torricellian tube remains high above the level of that in the 
 cup, we do at once assume that this is the effect of some cause; 
 for the unchanging state, or briefly the unchange, is maintained 
 in spite of a cause — the weight of the mercury — that we know 
 is tending to change it. 
 
 We are driven by these considerations to regard change as a 
 necessary element in our concept of effect, and if we first for- 
 mulate the definition that 
 
 An Unchange is the maintenance of an unchangi^tg state in spite 
 cf forces in operation tending to change it, 
 
 Then we may formulate our provisional definition of effect in 
 the following terms : 
 \ An Effect is a change or an unchange. 
 
 y 
 
 ■J 
 
 EFFECT, REASON, RESULT, CAUSE. 
 
 Reason. 
 
 39 
 
 Between these two kinds of effect there is a clear difference, 
 w^hich is easily distinguished, which is generally felt, and which 
 is, in fact, embodied in language ; for while we always call that 
 which produces a change the Cause of the change, we usually 
 do not give this title to that which opposes a change. This 
 latter we usually call a Reason. Tfie"viriatrons in the height 
 of the barometer 2ive caused by variations in the pressure of the 
 air ; but the constant pressure of the air is the reason why the 
 mercury does not sink to the level of the cup. The pull we 
 exert on the handle of the drawer is the cause of the drawer 
 opening : the drawer being locked is the reason it does not yield 
 to thej)ull. It would be quite inappropriate to say that the 
 ch'amiges in the weather are due to some reasons : but it would 
 be quite appropriate to say there must be some reason why the 
 weather does not change. It would seem that the full force of 
 effectuation is felt only when the effect is change, and that 
 when it is unchange the effectuation is felt to be attenuated and 
 diminished ; so that we may add to our definitions the following: 
 The cause of an unchange is called a Reason. ^^y^ 
 The definition of an effect as a change or unchange is 
 avowedly provisional, and needs to be completed. As already 
 explained, the nature of a thing, as it appears to us, depends on 
 the way in which we contemplate it. W^e may, if we please, 
 contemplate a change or an unchange in and by itself, merely 
 as change or unchange, without contemplating it as an effect. 
 In order to constitute it an effect, a change or unchange must 
 be contemplated from a special point of view, that is to say, 
 with reference to its causation. To become an effect it must 
 be associated in our minds with causation and a cause ; but as 
 we have not yet arrived at any definition of these terms, it 
 would not be legitimate to use therh in defining effect. Still, 
 we may legitimately go as far as this : we need not, and do not, 
 .always contemplate a change as an effect, but when we do regard 
 it as an effect we always contemplate it in relation with some 
 antecedent action on the thing changed. We need not regard an 
 unchange as an effect, but if we do so contemplate it, we con- 
 
 
 
40 
 
 ON CAUSATION. 
 
 rl 
 
 template it in relation with some action that maintains the thing- 
 unchanged. We may therefore develop our definition into this : 
 An Effect is a change or an unchange connected with an action 
 on the thing changed or unchanged. 
 
 Still the definition is not complete. A cup may fall and 
 break. The fall of the cup is a change produced on the cup, 
 and is an effect. The impact of the cup on the floor is an action 
 on the cup, and is connected with the fall ; but the impact ot 
 the floor on the cup is not the cause of the fall ; and why not ? 
 Evidently because it succeeds the fall. The cause of a change 
 must be sought in some action that precedes the change; it is 
 no use looking among the consequents for the cause. Most 
 writers on causation have been able to appreciate this, and 
 since the cause of a change must always precede the change, 
 they have muddled up causation with antecedence, and declare 
 that they are the same thing. They are not. Antecedence 
 often goes with causation, but there are many cases of causation 
 in which the cause does not precede the effect ; and there are 
 many antecedents of a change that are not its causes ; and to 
 identify causation with antecedence is a gross blunder, whether 
 the antecedence is invariable or not. 
 
 When the mercury in a Torricellian tube remains high above 
 the level of that in the cup, the pressure of the air, which is the 
 action that maintains the unchange, does not precede the main- 
 tenance of the unchange, which is the effect : it is continuous 
 with the unchange. They are contemporaneous. When the 
 action of the engine on the axles maintains the motion of the 
 motor car or the locomotive engine in spite of the forces in 
 action tending to arrest the motion, this action does not precede 
 the motion of the car or of the engine, but accompanies it. 
 The tension of a string that sustains a weight, and that is the 
 cause that prevents the weight from falling, does not precede 
 the suspension of the weight : it accompanies it. It begins at 
 the instant of suspension, it lasts while the suspension con- 
 tinues, and it ceases the instant the string is cut and the weight 
 falls. It is true that the drawer may be locked long before and 
 long after it is pulled upon to open it ; but it is not the drawer 
 being locked that is the cause of the unchange : it is the resist- 
 
 EFFECT, REASON, RESULT, CAUSE. 
 
 41 
 
 ance of the tongue of the lock ; and this resistance begins and 
 ends with the pull upon the drawer. 
 
 A time element, or time relation, of one kind or the other is 
 therefore a necessary and indispensable element in the definition 
 of effect, but the time relation is manifestly not the same in the 
 two kinds of effect, and therefore effect cannot be defined in a 
 single expression. The complete definition of effect must run 
 something as follows : — 
 
 An Effect is a change connected with a preceding action, or an 
 unchange connected with an accompanying action, on the thing 
 changed or unchanged. 
 
 Result. 
 
 * Some phenomena,' says Mill, * are in their own nature per- 
 manent ; having begun to exist, they would exist for ever unless 
 some cause intervened having a tendency to alter or destroy 
 them ... no object at rest alters its position without 
 the intervention of some conditions extraneous to itself: and 
 when once in motion, no object returns to a state of rest 
 . . . unless some new external conditions are superin- 
 duced. It, therefore, perpetually happens that a temporary 
 cause gives rise to a permanent effect. The contact of iron with 
 moist air for a few hours, produces a rust which may endure for 
 centuries ; or a projectile force which launches a cannon ball 
 into space, produces a motion which would continue for ever 
 unless some force counteracted it.' 
 
 As usual. Mill founds a general statement upon the enumeratio 
 simplex, without taking into consideration the instantia contra- 
 dictoria. It is not true of living animals that they never alter 
 their position without the intervention of some condition 
 extraneous to themselves : the mere internal accumulation of 
 energy is enough. But passing that, and making the necessary 
 qualification, Mill's limitation of the assertion to some pheno- 
 mena, as if it were not true of all, is utterly unjustifiable. If 
 the first Law of Motion is true, if Mill's own Law of Universal 
 Causation is true, that no event happens without a cause, it is 
 difficult to see how any change can take place in any * pheno- 
 menon ' whatever without a cause ; and it seems clear that 
 
 f 
 
 If 
 
 ■-1 
 
 I f i 
 
 I 11 
 
 
42 
 
 ON CAUSATION. 
 
 EFFECT, REASON, RESULT, CAUSE. 
 
 43 
 
 If ' 
 It i 
 
 not some phenomena only, but all phenomena whatever, are in 
 their nature permanent, and having begun to exist will exist for 
 ever, unless some cause intervenes to alter them. Mill adduces 
 these instances as instances of permanent effects ; but here he 
 is evidently using the word effect, which he never defines except 
 as an invariable consequent, in a popular sense, and in a sense 
 which even popular usage does not always sanction. According 
 to my definition, a permanent state.is^not an effect unless it is 
 an unchange ; and none of these is an unchange. Once at rest, 
 a body needs no cause to keep it at rest, unless there is some 
 action on it tending to move it ; and without such action, its 
 remaining at rest is neither a change nor an unchange, and is 
 therefore not an effect. A body at rest needs a cause to set it 
 in motion, and the setting in motion, the change from rest to 
 motion, is an effect: but once in motion, its continuing in 
 motion is not an effect. When iron rusts, the rusting is an 
 effect, ?or it is a change from metallic iron to oxide ; but once 
 it is rusty, there is no cause in action tending to change it back 
 again, and therefore its remaining rusty is not an effect. In 
 none of these cases does the effect continue. None of them is 
 a permanent effect. What Mill means by a permanent effect is 
 that iron once rusted does not change back again, and that a 
 man once killed does not come back to life again. It is a 
 manifest misnomer to say that if an effect is not reversed, the 
 non-reversal is an effect. It is true that in common speech it 
 is a frequent practice, but by no means an invariable practice, 
 to say that an effect continues, even when the effect is a change, 
 and to speak of the state of death and the state of rust as effects ; 
 but these are not accurate expressions, are eschewed by accurate 
 speakers, and are utterly unpardonable in philosophical writing. 
 What persists when a body is brought to rest or set in motion, 
 when iron is rusted, or a, man is killed, is not the effect, not the 
 change, but the changed state— the new state that has resulted 
 from the change. A change implies a state from which and a 
 state to which the change is made, and the state brought about 
 by the change is a very different thing from the change itself, 
 which alone is the effect. The changed state is not the effect, 
 it is the result, and thus waarrive at a sixth definition :— 
 
 f 
 
 I 
 
 A Result is the changed state of a thing on which an effect has 
 -heen produced. — 
 
 Cause. 
 
 The definition of effect, as a change or unchange connected 
 with an action, points straight to the nature of cause. I do not 
 think it is possible to imagine any change or unchange that is 
 not produced by the action of some agent. Of course, it may 
 be said that things may exist or occur, although we cannot 
 imagine them ; but we are not here dealing with transcendental 
 possibilities. We are dealing with events in this world as we 
 know them in experience, and our experience is such that we 
 can no more imagine change to be produced or prevented 
 without action upon the thing changed, than we can imagine 
 ' resistance without extension, force without matter, or solid 
 without surface. In each case the one presupposes the other. 
 The only consideration that can be plausibly advanced against 
 this view is, I think, that we regard some changes as spon- 
 taneous. But by a spontaneous change we do not mean a 
 change produced without action on the changing thing, we 
 mean a change due to the action of the changing thing itself, 
 as contrasted with change due to the action upon it of some- 
 thing outside the changing thing. 
 
 The only formal repudiation of this doctrine is that of 
 
 Hume, which has already been examined. Hume taught that 
 
 there is no such thing as force or power, which I here call 
 
 action ; that it exists only in our imagination ; that the notion 
 
 we have of it rests upon no evidence, and corresponds with 
 
 nothing in the external world. His reason for this opinion was 
 
 that we gain our notion of force or power not from any single 
 
 individual experience, but as a generalisation from many 
 
 experiences; and he thought that in this it contrasted with 
 
 our notions of resistance, extension, and motion. We now 
 
 know that in this he was mistaken. All such notions are 
 
 generahsations from many evxperiences, and the notion of force 
 
 or power is not singular in this respect, does not differ in this 
 
 respect from other primitives, nor is it invalidated, as a true 
 
 -representation of externals, by being a generalisation. 
 
 ff- s 
 
A. 
 
 ! 
 
 11 
 
 l! 
 
 . . ON CAUSATION. 
 
 But all Hume's discussion of its origin is beside the qiies- 
 tion. Whatever its origin, it is indisputable that we have this 
 notion of force, or power, or action, and that ^«/^g"<lj\^^ 
 having a real existence in the world outside of us ; and the 
 crucial test is this : that we act upon the assumption that it 
 does exist, and that the consistent action, on that assumption 
 of the whole human race has never brought anyone up against 
 experience that contradicts the assumption. This is the ulti- 
 mate and unimpugnable test of empirical truth. This test 
 being satisfied, it is quite out of our power to doubt that the 
 assumption is true. We may in words express a do^ubt or 
 even a denial, for language was acquired by man in order that 
 he might deny his beliefs ; but in fact we do not and cannot 
 doubt it. It is quite possible to deny in words that matter 
 exists that there is an external world to be appreciated, and 
 that we have minds to appreciate it with ; it is quite possible 
 to deny that things that are equal to the same thing are equal 
 to one another; but the test of belief is action; and when we 
 come to act, we act in conformity with the beliefs which we 
 deny, and prove by so doing that our denial is a sham and an 
 imposture-an imposture that does not impose even upon 
 
 ourselves.. . . ^ -, r. •^- r 
 
 We may take, therefore, as our first provisional definition ot 
 
 a cause : 
 
 A Cause is an action. • • i . • 
 
 Though we may speak of change and of unchange in isolation 
 and abstraction from other things, yet in thinking of change 
 or unchange it is impossible to expel from our minds the 
 notion of a thing that changes, or that is prevented from 
 changing. Change and prevention of change alike imply a 
 changeable thing. That which produces change in a thing 
 cannot be thought of othervvise than as an action on that thmg 
 either from without or from within. That which keeps a thing 
 unchanged in spite of something that is trying or tending to 
 change it, cannot be thought of otherwise than as an action on 
 or by the unchanging thing. Hence, by a cause not only do 
 we always mean an action, but we always mean an action on 
 a thing It is quite possible to entertain the notion of action 
 
 EFFECT, REASON, RESULT, CAUSE. 
 
 45 
 
 vv'ithout taking into account anything acted on, as when we 
 contemplate the rotary action of the arms of a windmill ; but 
 when we so contemplate an action we exclude from our minds 
 the notion of cause. Cause always carries with it the notion, 
 not merely of action, but of the transference of action from the 
 acting agent to the thing acted on, or the initiation of action by 
 the changing or unchanging thing; and the notion of cause is 
 not complete unless this transference or initiation of action is 
 taken into account. Hence we arrive at a further stage in our 
 provisional definition of cause : 
 
 A Cause is an action upon a thing. 
 
 But not yet is our notion of cause complete. We may 
 contemplate an action upon a thing in and by itself, without 
 letting our contemplation run forward to the consequent 
 change or prevention of change Sn the thing acted on ; and 
 unless we do thus extend our contemplation, our notion of 
 cause is incomplete and unformed. When we contemplate 
 the action of a breeze blowing upon a rock, we do not, or need 
 not, regard this action as the cause of any change or unchange 
 in the thing acted on. To complete our concept of cause, we 
 must add to the provisional definition a reference to the change 
 or unchange that is connected with the action on the thing, and 
 develop our definition of cause as follows : 
 
 A Cause is an action connected with a change or unchange in the 
 ihing acted on. 
 
 The pressure of steam in a boiler is an action on the boiler: 
 the rise in temperature of the boiler is a change in the boiler — 
 the thing acted on — and is connected with the steam pressure ; 
 but the pressure of steam is not the cause of the rise in the 
 temperature of the boiler : it is the other way about. The 
 pressure of the air is an action on the locomotive engine, and 
 it is connected with the unchange — the running of the loco- 
 motive — tfor it increases with the speed ; but it is not the cause 
 of the unchange. Evidently some further qualification is 
 required in the definition. Why cannot the pressure of steam 
 in the boiler be the cause of the rise in temperature of the 
 boiler ? Manifestly because the steam-pressure does not 
 precede, but follows the rise of temperature. Why is not the 
 
 11 
 
 /%. 
 

 46 
 
 ON CAUSATION. 
 
 pressure of the air the cause of the running of the locomotive ? 
 Manifestly because, the running being an unchange, the pressure 
 of the air is not contemporanous with it. The pressure exerted 
 its action before the running began, and continued after the 
 running had ceased. In order, therefore, to accommodate our 
 definition to these considerations we must modify it as follows : 
 
 A Cause is an action connected with a following change or a contem- 
 poraneous unchange in the thing acted on. 
 
 There are some usages that conflict with this doctrine. One 
 of these is that we often give the name of cause to that which 
 is not an action. We say the cause of the stoppage of a motor 
 car is a broken sparking plug, a leak in the water circulation, 
 grease in the commutator, dirt in the carburettor, and so forth. 
 Similarly, we say the cause of a man's death is failure of his 
 heart to'act ; the cause of the stoppage of the machinery is the 
 the stoppage of the engine ; the cause of -the stoppage of the 
 engine is the fire going out ; and so forth. In each the cause 
 is not an action, but is the cessation of action, or the agent 
 which produces cessation of action ; and in every such case, 
 the change, which is the effect, is the cessation of an unchange. 
 Now an unchange is the maintenance of a continuous state m 
 spite of the operation of forces tending to change it : and that 
 which we call the cause of the cessation of the unchange, or the 
 destruction of this continuous state, is not an actual cause, not 
 an action, but the removal or cessation of the cause of the 
 unchange. In each of the foregoing cases, what we call a, 
 cause is really the removal or cessation of a cause. The un- 
 changed motion of the car is caused by the action of the 
 sparking plug, of the water circulation, of the commutator, of 
 the carburettor ; arrest any of these actions, and the running 
 of the car ceases, and ceases by the operation of causes- 
 friction, etc.— that were all along tending to stop it, and are now 
 permitted, by the cessation of the causes of the unchange, to 
 become effectual. Similarly, the life of man is an unchange 
 maintained by the action of the heart in spite of causes in 
 action tending constantly to bring life to an end. Cessation of 
 the heart's action does not kill the man, but allows him to die. 
 The movement of the machinery is an unchange, mamtamed. 
 
 EFFECT, REASON, RESULT, CAUSE. 47- 
 
 in spite of causes tending to end it, by the action of the engine. 
 The stoppage of the engine does not stop the machinery, but 
 allows it to be brought to rest by friction and other resistances. 
 It is scarcely consonant with our notion of cause to call the 
 cessation of action a cause, but, undoubtedly, in individual 
 cases that occur in experience, such as those that have been 
 instanced above, we do in fact regard the cessation of action 
 •as a cause, although a stricter logic would compel us to look 
 upon it as the removal of a cause. If the latter view is to pre- 
 vail, the last definition will stand as the final definition of Cause, 
 but if we are to fall in with current usage, our definition will 
 run : 
 
 A Cause is an action, or cessation of action, connected with a 
 sequent change or accompanying unchange in the thing acted on. 
 
 Another usage that conflicts with both of these definitions is 
 that of Mill and the logicians, as well as of other writers who 
 should know better, in speaking of things which are not actions 
 nor cessations of action as causes. It is fruitless to try to fix 
 responsibility for the practice, but I am afraid that ultimately 
 It might be traced to writers on Causation. A flagrant example 
 is afforded by writers on medicine, who still divide the causes 
 of disease into predisposing causes and exciting causes. Among 
 the predisposing causes it is usual to enumerate the age and 
 sex of the patient, the climate and locality of his residence, his 
 occupation, and so forth; and none of these is an action,' nor 
 is any of them a cessation of an action. Occupation is 
 indeed action, but it is not action upon the thing changed— 
 upon the patient. It is action by the patient, a very different 
 thing. It is evident that in calling these passive states causes 
 of disease, we are using the word cause in a very strained and 
 unnatural sense, and this is often acknowledged even by 
 medical writers themselves. Yet it is beyond doubt that these 
 states have an influence upon the effect. Certain diseases are 
 limited to a certain age ; others are limited to one sex ; others 
 are found to attack those only who live in certain localities or 
 pursue certain occupations ; and yet there is a felt and acknow- 
 ledged incongruity in calling them causes. No one has ever 
 specified what it is that arouses this feeling of incongruity, but 
 
48 
 
 ON CAUSATION. 
 
 hi 
 
 I think there can be no doubt that it arises from the recognition 
 hat ty are neither actions nor cessations of action and ha 
 t is only to actions, and perhaps to cessations of act on ha 
 hi term cause can be properly applied. The connection that 
 hse passive circumstances have with the effect a connection 
 vhchTs undoubted, and cannot be questioned fbr a moment 
 s that they are CondtUons of the effect; and this leads us to 
 Inquire !nto the meaning of Condition, and to ascertain in what it 
 differs from Cause. 
 
 Summary, 
 
 This Chapter is an examination of the relation of which the 
 twi lerms are Cause and Effect, and the ratio, or relating 
 
 " eS; ;; iSSSy connected with the idea of change, and 
 
 ,e.e%ct is tLt ^-^-^--^7::^ % 
 
 :rs;.vlptrXatiL\\v:re:c;\he definition that an E^^^^^ 
 La change connected with a preceding action or an unchange 
 connected with an accompanying action o" ^ ^hing^ 
 
 The cause of an unchange is often called a Reason. 
 
 ?he changed state that is left when an effect has been pro- 
 
 'X'icSst: approximations we reach the definition that a 
 Cau e IS an act.on'(or cessation of action) connected wi h a 
 JquenJ change or accompanying unchange of the thing acted 
 
 on. 
 
 CHAPTER III. 
 
 CONDITION. 
 
 While it is generally understood that a cause and a con- 
 dition are different things, and stand in different relations to 
 the effect, yet even in common speech and in practice they 
 are often confused, and writers on causation admit no dis- 
 tinction whatever between them. Mill was the worst offender 
 in this respect, and his evil example has corrupted all subse- 
 quent writers. I do not know of any writer on the subject 
 who formally distinguishes between cause and condition, 
 though all writers use both terms ; but they jumble them up 
 together, sometimes using them interchangeably, and sometimes 
 assuming a difference without ever distinguishing them. 
 
 Whenever a distinction is made in common speech, we may 
 be pretty sure that it represents and indicates a distinction in 
 thought which the common user feels and appreciates, though he 
 is usually unable to formulate and define it. Not one person in a 
 thousand makes a mistake in the use of the phrases * I did it * 
 and ' I have done it,' and not one person in a thousand could 
 formulate and explain the precise difference in the meanings 
 of the two. Whenever two different words or phrases are used 
 to express nearly the same thought, it will always be found, 
 that they never express quite the same thought. It is, in fact»; 
 impossible to keep two commonly used words in the same 
 language synonymous. They soon begin to take on different 
 meanings and to be used on different occasions, and gradually 
 
50 
 
 ON CAUSATION. 
 
 H 
 
 the meanings diverge more and more. A familiar instance is 
 in the different meanings that now attach to large, big, great, 
 and gross. In the face of such common usage, the proper 
 attitude of a careful student of language and thought is not 
 to assume a haughty superiority to the commonalty who have 
 made the distinction ; not to assume, as Mill does, that it is 
 the mere confusion of ignorance and illiteracy, pretending a 
 difference where no distinction exists ; but to examine, probe, 
 penetrate, and realise the thought that underlies the practice, 
 to discover the difference, and to clothe it in an appropriate 
 definition. Cotton stuffs are often confounded with woollen 
 stuffs, to the disadvantage of the purchaser; but not on that 
 account ought the expert to persuade the purchaser that there 
 is no difference between cotton and woollen, and that he has 
 been all his life calling one thing by two names. A sure, 
 though not a clear, discernment has convinced him that there 
 is a difference, though he cannot say in what the difference 
 consists. A helpful guide would teach him how they are to 
 be distinguished. Mill, however, and every subsequent logician, 
 finding that the populace makes a distinction between cause 
 and condition, but is not very clear as to the nature of the 
 distinction, seek, not to find and formulate the difference 
 between them, but to persuade us that no difference exists. 
 
 That Mill did dimly, and in his fumbling manner, feel, rather 
 than recognise, that there is a difference between cause and 
 condition appears from his treatment of them. He says ' It 
 is very common to single out one only of the antecedents 
 under the denomination of Cause, calling the others merely 
 Conditions. . . . The real Cause is the whole of these ante- 
 cedents: and we have, philosophically speaking, no right to 
 give the name of cause to one of them, exclusively of the 
 others.' This, it may be observed, is his sixth definition of 
 cause, different from all the previous five. ' What, in the case 
 we have supposed [that of eating a particular dish and dying 
 in consequence], disguises the correctness of the expression, 
 is tbis : that the various conditions, except the single one of 
 eating the food, were not events^ hut_itaies^^j^,ossessing more or 
 less of permanency.' Supposing" thi s were , ihe- -correct dis- 
 
 i^diim ifl 'T*ifa.,>A« 
 
 CONDITION. 
 
 5^ 
 
 tinction between causes and conditions, surely it is a distinction 
 worth making, and entitles them to separate treatment. Again, 
 he says ' There is, no doubt a tendency to associate the idea 
 of causation with the proximate antecedent event rather than 
 with any of the antecedent states: If Wis' is so, the obvious 
 duty of an investigator is to discover the reason and meaning 
 of this tendency, and this Mill seems to feel, for he gives a 
 reason, a very inconclusive reason, which explains nothing, 
 but still he gives one, 'the reason being that the event not 
 only exists, but begins to exist immediately previous; while 
 the other conditions may have pre-existed for a considerable 
 time.' ' But though we may think proper to give the name 
 of cause to that one condition, the fulfilment of which com- 
 pletes the tale, and brings about the effect without further 
 delay ; this condition has really no closer relation to the effect 
 than any of the other conditions has. All the conditions were 
 equally indispensable to the production of the consequent ; 
 and the statement of the cause is incomplete unless in some 
 shape or other we introduce them all.' 'The cause, then, 
 philosophically speaking, is the sum total of the conditions.' 
 Thus, after fluttering on the edge of finding a distinction 
 between cause and condition, he makes up his mind that they 
 are identical, and comes down with a flop on the wrong side. 
 It would be difficult to find an argument more perverse, and 
 the statements by which it is supported are nearly all of them 
 •erroneous. 
 
 If, as Mill says, we think proper to give the name of cause 
 to one antecedent rather than to the rest, is it not manifest 
 that we do so because we recognise a difference between this 
 antecedent and the rest ? Why else should we single it out 
 for different treatment ? The bestowal of a separate and 
 different name is prima facie evidence that a ditfference is felt 
 to exist; and Mill, though he does not discover the true 
 difference, yet does discover a difference, and then treats it 
 as if it were non-existent. If a glass bottle is broken by the 
 blow of a stick, is it true to say that the blow of the stick has no 
 •closer relation to the breaking of the bottle than the existence 
 of the stick, or the muscles of the arm of the man who struck 
 
52 
 
 ON CAUSATION, 
 
 CONDITION. 
 
 S3 
 
 41 
 
 
 the blow ? And is the * statement of the cause ' of the fracture 
 of the bottle incomplete unless in some shape or other we 
 introduce the growth of the tree from which the stick was 
 cut and the birth of the man who struck the blow ? for they 
 were * equally indispensable to the production of the conse- 
 quent.' ^Nothing.' says Mill, 'can better show the absence 
 of any ground for the distinction between the cause of a 
 phenomenon and its condition, than the capricious manner 
 in which we select from among the conditions that which we 
 choose to denominate the cause.' Never was assertion more 
 unwarrantable. As well might a man who is colour blind 
 assert that nothing can better show the absence of any ground 
 for the distinction between red and yellow than the capricious, 
 manner in which we select from the yellows that which we 
 choose to denominate red. The distinction is there right 
 enough. Between cause and condition there is a distinction 
 that is perfectly clear and very useful, and that is none the 
 less a clear and useful distinction because it is not always, 
 observed; because we do not always need to observe it;, 
 or because Mill and his successors are too blind to ob- 
 serve it. . .L -J f 
 Mill says we have a * tendency' to associate the idea ot 
 causation with antecedent events rather than with antecedent 
 states. If this were so, it would be a distinction of sufficient 
 importance to warrant us in separating the events (causes) from 
 the states (conditions) and discussing them apart ; and though 
 this is not the truth, yet it is an adumbration of the truth.. 
 I^Iill would have been much nearer the mark, though he would 
 not have been within it, if he had said that we associate the 
 idea of effect with events. An event is that which comes out 
 of something else, and an effect is that which comes out of the 
 cause. An event, whatever else it may be, is a change, and as. 
 we have seen, an effect is often a change, and is always asso- 
 ciated with change. We do not necessarily associate the idea 
 of causation with either events or antecedence, but we may 
 associate it with an event if we contemplate the event as an 
 effect. Nor is it true that we associate the idea of condition 
 with '' states possessing more or less of permanency ' merely 
 
 because they are states and more or less permanent. The 
 state of activity of an engine is a state possessing more or less 
 of permanency, but we do not regard it as a condition of the 
 movement of the train. We regard it as the cause, and rightly 
 so regard it, because it is an action. A cause is an action, and 
 so to regard cause points to the difference between cause and 
 condition, for 
 
 A Condition is a passive state. 
 
 That is the true distinction between cause and condition. 
 Cause is active : Condition is passive. A cause is an action : 
 a condition is a passive state; not necessarily a permanent 
 state, though as a state it must have some endurance, even if the 
 endurance is but brief. One of the conditions of the discharge 
 of a gun is that the hammer must be at cock. This is a passive 
 state, but it is not a permanent state. It must, however, have 
 some endurance, even though the endurance may be but 
 momentary. 
 
 Clearly, however, the definition of a condition as a passive 
 state is not a complete definition with reference to any given 
 case of causation. There are many passive states of many 
 things quite uncortnected with the causation of any given effect. 
 The position of the hammer of a gun at half-cock is a passive 
 state, but it is not a condition of the occultation of Jupiter. 
 To complete the definition of a condition it is necessary to state 
 the connection of the passive state with the causation of the 
 effect. A cause is an action upon a thing, connected with a 
 change or unchange in the thing acted on. A condition is a 
 passive state : of what ? Of the thing acted on ? It would 
 seem so, for that is the only thing admitting of a condition 
 mentioned in the definition ; and many instances can be adduced 
 of conditions which are passive states of the thing acted on. 
 The pulling of the trigger is the cause of the discharge of a 
 gun : the position of the hammer at full cock, and the presence 
 of a cartridge in the barrel, are passive states of the gun, the 
 thing acted on, and satisfy the definition of conditions. The 
 striking of a key on the piano is the cause of the sound of 
 the note. The tension of the wires and the integrity of the 
 mechanism are conditions of the occurrence of the sound : they 
 
S4 
 
 ON CAUSATION. 
 
 'I'. 
 
 
 are passive states of the thing acted on. The application of 
 moisture to the flap of an envelope is a cause of the flap stick- 
 ing. The presence of a film of gum on the flap is a condition 
 of the flap sticking : it is a passive state necessary, to the occur- 
 rence of the effect. In this case, we may regard the presence 
 of the film of gum as a state of the envelope itself, or we may 
 regard it, more accurately perhaps, as adjoining and in contact 
 with the envelope, but not a part of the envelope— a passive 
 state, not of the thing acted on, but of something about the 
 thing acted on. In other cases the distinction becomes clear. 
 The cause of a plant's growth is the action of heat on the plant ; 
 but the effect on the plant would not be produced but for a 
 condition— the existence ofjgtad^within reach of the roots of 
 the plant. This condition is a passive state, not of the plant— 
 the thing acted on— but of the soil in which the plant grows, 
 that is, of something about the plant. The cause of the sound 
 of a bell is the action of the tongue on the bell : but this effect 
 would not be produced were it not that the bell is bathed in air, 
 and the existence of the air is a passive state, not of the bell, 
 but of something about the bell. The cause of a plant twining 
 up a support is the action of the plant in rotating about an 
 axis ; but the effect would not be produced but for the presence 
 of a 'support up which the plant could twine. The presence of 
 the support is a condition of the effect, and is a passive state, 
 not of the plant, the thing which, acting on itself, produces the 
 effect, but of something about the plant. And so we find with 
 many other conditions, that they are passive states, not neces- 
 sarily of the thing acted on, but of something about that thing. 
 Thus we must modify our first tentative definition of a condi- 
 tion and say 
 
 A Condition is a passive state of or about the thing acted on by a 
 
 cause. 
 
 The definition is not yet complete, however. It requires 
 further limitation, for there are many passive states in and 
 about a thing acted on which yet are not conditions of any 
 effect produced by the action. The sun shines upon a wall, 
 and by its action warms the wall ; and against the north side 
 of the wall rests a ladder. The presence of the ladder is a 
 
 J -! 
 
 CONDITION. 
 
 ss 
 
 passive state about the thing acted on, but it is not a condition 
 of he warniing of the wall. A red-haired man takes mediane 
 in a room with a parquet floor and a painted ce Img^ Th^ 
 medicine produces its effect, but the red hair, the parquet 
 Zo Z the painted ceiling, though they are passive states of 
 and kbout the'thing acted on, are not conditions of the produc 
 tion of this effect. A fall of rain causes a road to be muddy . 
 he du Jon the road is a condition of the road becoming 
 muddy, but the presence of a house by the side of the road 
 Tough it is a passive state about the thing acted on, is not a 
 condlion of the formation of mud. It is clear that a pass ve 
 state of or about the thing acted on need not be a cond t on 
 of the effect of that action, and is not a condition unless the 
 existence of the state is necessary to the effect, or material to 
 the effect If a ship is careened by a gale, we may cause her 
 o rightterself by taking in sail. The action of taking m sa. 
 s the cause of the ship's righting. But no taking in of sail 
 would cause this movement of the ship unless she -ere already 
 Treened. The careening of the ship is a passive state of he 
 th n' upon which the cause acts, and it is necessary to the 
 re dt Being a passive state, it is not a cause ; and it w. 1 be 
 admhted thatSt would be an absurd misnomer to speak of the 
 careening of the ship as a cause of her righting herself. But 
 h careening is necessary to the righting. It is a condi ion 
 an indispensable condition, of her nghting herself. Hence we 
 orrivp at the following complete definition. 
 TcoLl^ion .s a pZ.ve late of or ahout the thins acted on hy 
 
 n rnii^^p and material to the effect, 
 
 A an example of the confusion which he attributes to peop e 
 in generatbut' which really exists in his own mind and scarcely 
 anywhere else but in the minds of his followers. Mill gives the 
 Slowing example, which it will pay us to examine in some 
 
 '''< A stone thrown into water falls to the bottom^ What are 
 the conditions of this event > In the first place there must be 
 a stone and water, and the stone must be thrown into the 
 water but these suppositions forming part of the enunciation 
 If the phenomenon iiself, to include them among the conditions 
 
 ll 
 
 • I'm 
 
56 
 
 ON CAUSATION. 
 
 would be a vicious tautology.' To include them all among the 
 conditions would certainly be erroneous, for the throwing of 
 the stone is not a passive state, but an action ; and an action 
 directly concerned, as an action, with the effect. It is there- 
 fore not a condition, but a cause. The existence of the stone 
 and of the water are certainly conditions, and are so according 
 to Mill's own definition, for they are included in the sum total, 
 * the whole of the contingencies of every description, which 
 being realised, the consequent invariably follows.' ' The next 
 condition is, there must be an earth : and accordingly it is 
 often said that the fall of the stone is caused by the earth ; or 
 by a power or property of the earth, or a force exerted by the 
 earth, all of which are roundabout ways of saying that it is 
 caused by the earth ; or, lastly, the earth's attraction ; which 
 also is only a technical mode of saying that the earth causes 
 the motion, with the additional peculiarity that the motion is 
 towards the earth, which is not a character of the cause but of 
 the effect.' It would not be easy to find a better example of 
 Mill's thorough muddleheadedness. No one with any sense of 
 propriety in the use of words, or with any attention to the 
 meaning of words, could possibly say that the earth was the 
 cause of a stone thrown into water falling to the bottom ; but 
 anyone who should say that the fall of the stone was caused by 
 a power of the earth, or by a force exerted by the earth, or by 
 the earth's attraction, would assert precisely and accurately 
 what the cause is. These are not roundabout ways of saying 
 that the fall is caused by the earth : on the contrary, if anyone 
 were inaccurate enough, and slipshod enough, to speak of the 
 fall being caused by the earth, he would be using an elliptical 
 expression, taking it for granted that his hearers would under- 
 stand that he was using * the earth ' for Ihe sake of brevity, 
 instead of the power, or force, or attraction exerted by the 
 earth, or briefly, the action of the earth : in short, that he was 
 speaking of the agent as a cause when he meant the action of 
 the agent, a mistake not infrequent with uneducated people, 
 but one that makes us stare when we find it formally adopted 
 by the authoritative writer on causation. 
 
 * Let us now pass to another condition. It is not enough 
 
 Ul 
 
 CONDITION. 
 
 57 
 
 that the earth should exist ; the body must be withm that dis- 
 tance from it, in which the earth's attraction preponderates 
 over that of any other body.' Well, yes, so it must, for if not, 
 there would be no water for it to sink in. At this rate a book 
 the size of Mill's Logic would be needed to contain a list of all 
 the conditions necessary to the sinking of the stone. We should 
 have to go back to the geological conditions under which the 
 stone was formed : and so back to the primordial nebula that 
 gave rise to the solar system. ' Accordingly we say, and the 
 expression would be confessedly correct, that the cause of the 
 stone's falling is its being mthin the sphere of the earth's attrac- 
 tion.' It is cool of Mill to say that this expression would be 
 confessedly correct. I know not who has made the confession, 
 but I know that not the rack nor the thumbscrews would wring 
 such a confession out of me. Being within the sphere of the 
 earth's attraction is not an action, and therefore cannot be a 
 cause of anything. It is a state, and for the purpose in hand 
 a passive state, and therefore is not a cause, but a condition. 
 
 ' We proceed to a further condition. The stone is immersed 
 in water : it is therefore a condition of its reaching the ground, 
 that its specific gravity exceeds that of the surrounding fluid, 
 or in other w^ords that it surpass in weight an equal volume 
 of water. Accordingly anyone would be acknowledged to 
 speak correctly who said, that the cause of the stone's going 
 to the bottom is its exceeding in specific gravity the fluid in 
 which it is immersed.' Mill might make this acknowledgment, 
 but I doubt if anyone else would, and for my part I certainly 
 should not. According to the rule I have laid down, the 
 specific gravity, being a passive state and not an action, is a 
 condition, not a cause. 
 
 Mill sinned against the light. He was not ignorant of the 
 view here adopted : it was brought to his notice by a reviewer, 
 and after examination he deliberately rejects it. The reviewer 
 says ' we always apply the word cause rather to that element 
 in the antecedents which exercises force.' Thus he had the 
 temerity to defy Hume, and he came nearer than any other 
 writer to the view taken in this book. One of Mill's instances 
 is ' The army was surprised because the sentinel was off his 
 
 I 
 
 1 
 
 • I 
 
 I 
 ( il 
 
58 
 
 ON CAUSATION. 
 
 !' 
 
 ff 
 
 |. 
 
 » 
 
 post.* He considers this as a justifiable and proper expression, 
 which no doubt it is, and that it means 'The cause of the 
 army being surprised was the sentinel's being off his post/ 
 which it does not, or does not necessarily. Mill, though he 
 always expresses himself clearly, rarely expresses himself 
 accurately, and here he is inaccurate. ' Because ' may indicate 
 a cause, a condition, or a reason. What Mill is contending 
 for is that it is correct to use the second expression about the 
 surprise of the army. The reviewer says, and I agree with 
 him, that it is incorrect, and I add that it is incorrect because 
 the sentinel's being off his post is not an action, but a passive 
 state, and therefore a condition. The reviewer says, and again 
 I agree with him, that the allurement or force which drew the 
 sendnel off his post may rightly be called the cause of the 
 surprise of the army, and to this Mill objects that it can 
 scarcely be wrong \o say the surprise took place because 
 the sentinel was absent ; and right to say it took place because 
 he was bribed to be absent. This is ignoratio elenchi. We are 
 dealing with causes only, and ' because ' may refer to causes, 
 conditions, or reasons, and Mill, like other logicians, never 
 uses a univocal word if he can find an ambiguous word to 
 serve his purpose. Let us put it into accurate language. It is 
 wrong to say the cause of the surprise was the sentinel's being 
 off his post, for that implies a passive state and a condition. 
 It is right to say the cause of the surprise was the sentinel's 
 going off his post, or deserting his post, for these imply action v 
 and for the same reason the bribing of the sentry may properly 
 be called a cause of the surprise. 
 
 In every book on medicine we find age, sex, race, time of 
 year, climate, and so forth enumerated among the causes of 
 diseases. It is clear that none of these is an action.^ None 
 of them therefore can be a cause of disease. Occupation also 
 is called a predisposing cause of disease ; but though the 
 occupation of the patient is an action, it is an action not on 
 the patient, the thing changed, but by the patient, which is- 
 a very different thing. When occupation is a factor in pro- 
 ducing disease it is therefore usually a condition, not a cause ; 
 but there are some cases in which it may properly be called 
 
 CONDITION. 
 
 59 
 
 a cause. Dry grinding produces a quantity of irritatmg dust, 
 which is inhaled by the dry grinder, and irritates the dehcate 
 walls of the air-cells of the lungs, in such a way as to produce 
 inflammation in them, which is called grinder's phthisis. 
 In this case the occupation of the patient is an indirect cause 
 of the disease. It causes a result— the presence of dust in the 
 air— which is a condition of the disease. 
 
 A condition has been defined as a passive state . . . material 
 
 to the effect, or such that without it the effect would not have 
 been produced ; and according to this definition, every con- 
 dition must be necessary to the effect ; yet we often speak of 
 favouring conditions, with the implication that they favour or 
 assist the pro"ductton^T)f the effect, which yet might be pro- 
 duced without them. The expression ' favouring condition ' 
 is a convenient expression, and is not inaccurate if it is 
 properly understood and defined. Under given conditions a 
 seed will germinate, and the plant will grow to maturity, 
 flower, and seed. All the conditions necessary to its life and 
 growth to maturity must therefore have been present ; but 
 under other conditions of aspect, moisture, soil, and so forth, 
 it might have reached maturity sooner, might have attained 
 a larger growth, might have produced more flowers and more 
 seed and might have lived longer. These other conditions 
 were not necessary to the life, growth, an^-rnaturity of the 
 plant ; but they favoured its^Tlellrpwth,., and ^maturity ; and 
 though not necessary to the production of some efl"ect, they 
 were necessary to the full or extra effect over and above that 
 produced in the first set of conditions. A favouring con- 
 dition is, therefore, a condition without which some effect 
 will be produced on a given thing by a given cause, but with 
 which more of that effect will be produced, or the effect will 
 be produced more speedily by the operation of the same cause, 
 or both. With respect to the production of some effect, the 
 second condition is a favouring condition: with respect to the 
 production of the extra effect, or the earlier effect, it is a 
 necessary condition. 
 
 There is another sense in which the terms necessary condi- 
 tion and favouring condition are contrasted. If in certain con- 
 
6o 
 
 ON CAUSATION. 
 
 ditions a certain amount of an action is necessaty to produce a 
 certain effect, and if, when a new condition is introduced, less 
 of that action will produce that effect, then this new condition 
 is called a favouring condition. It is not necessary to the pro- 
 duction of the effect by a given intensity of action, but it is 
 necessary to the production of the effect by a less intensity of 
 action. Thus, though a condition is always necessary for the 
 production of an effect by a given action, yet it is convenient 
 and justifiable to distinguish between necessary and favouring 
 conditions if we bear in mind the conventional meanings of 
 * favouring.' 
 
 Frost, if sufficiently intense, will infallibly kill the blossom 
 of pepin fruits. A less degree of frost will not kill the blossom 
 if it is dry, but will infallibly kill it if it is wet. Wetness of 
 the blossom is a necessary condition to the destruction of the 
 blossom by this less degree of frost, but it is not a necessary 
 condition to the destruction of the blossom by frost in general. 
 It is called, and may justifiably be called, a favouring condition 
 of the killing of the blossom by frost. 
 
 Summary. 
 
 A condition has never hitherto been satisfactorily distin- 
 guished from a cause. The true distinction is that a cause is 
 an action, a condition a passive state. 
 
 By successive approximations we reach the definition that a 
 condition is a passive state of or about the thing acted on by 
 the cause, and material to the effect. 
 
 The difference between a necessary and a favouring condition 
 is verbal. A condition is always necessary to the production 
 of a given effect by a given action ; but, if, under an additional 
 condition, the effect would be produced sooner, or more of the 
 effect would be produced, or the same effect would be produced 
 by less of the action, then that additional condition may be 
 termed a favouring condition with respect to the general causa- 
 tion of that effect, though it is a necessary condition with respect 
 to particular cases. 
 
 V CHAPTER IV. 
 
 CAUSATION. 
 
 We may now turn to the consideration of the third con- 
 stituent in the relation. We have considered the terms— Cause 
 and Effect— and we now turn to the consideration of the Imk, 
 or ' relating relation ' which binds them together, and which I 
 call the ratio. The question we now have to discuss is What is 
 the nexus between cause and effect ? or. Given an action on a 
 thing, and a following change or contemporaneous unchange m 
 that thing, what is it that converts this time relation mto a 
 relation of causation ? in short. What is the mark or character 
 
 of Causation ? 
 
 Hume, after arguing at length that there is no connection at 
 all between cause and effect, astounds us by defining their rela- 
 tion as ' if the first object (the cause) had not been, the second 
 (the effect) had never existed,' and thus declares not merely 
 connection, but necessary connection, between them. Mdl, as 
 we have seen, proposes one definition after another, not as suc- 
 cessive approximations to a final clarified expression, not even 
 as alternatives of equal value, but he wanders on, giving one 
 definition after another, not noticing that they are incompatible, 
 and seemingly forgetting, when he formulates a new one, that 
 he had ever formulated one before. The two qualities on which 
 he most insists are invariableness and unconditionalness, but 
 he soon abandons invariableness, and he insists throughout that 
 conditions are necessary to causation. Dr. Fowler pins his 
 
62 
 
 ON CAUSATION. 
 
 CAUSATION. 
 
 63 
 
 faith to invariableness of succession, but Mr. Welton denies 
 sequence as being necessary to causation, and in this no doubt 
 he is right ; but he goes farther, and denies that sequence or 
 any time relation enters into causation, and in this he is 
 unquestionably wrong. According to him, * the relation of 
 causation is found in the securing of those conditions, which 
 are, consequently, at once both cause and effect,' not a very 
 illuminating statement, and not quite consistent with his defi- 
 nition of cause as * a totality of conditions whose existence 
 secures the effect ' — causes it, in fact. Professor Carveth Read, 
 whose pronouncements always deserve consideration, enume- 
 rates five marks of causation, which it will be well to examine, 
 since one or more of them are adopted by most other writers. 
 
 * The Cause of any event, then, when exactly ascertainable, has 
 five marks: it is (quantitatively) equal to the effect, and is (quali- 
 tatively) its immediate^ unconditional y invariable antecedent.' 
 
 The quantitative equality of cause and effect is frequently 
 assumed and asserted, but it seems to me to rest upon a very 
 insecure foundation, and to be based upon very misty notions 
 of what a cause is, and of what an effect is. The instances 
 given are almost always chemical combinations, and it is said 
 
 * When oxygen combines with hydrogen to form water, or with 
 mercury to form red precipitate, the weight of the compound 
 is exactly equal to the weight of the elements combined in it.' 
 No doubt it is, but what are equated here are two weights, and 
 I do not see how it can be maintained that the weight of the 
 elements is the cause, or the weight of the compound the effect, 
 of the combination. The causes of the combination of oxygen 
 and hydrogen are first, the mixing of them, and second, the 
 passage of an electric spark through them ; and I cannot see 
 that the mixing is equal to the effect, or that the spark is equal 
 to the effect, which is not the weight of the water, but the 
 formation of water. The effect in this case is a change-— the 
 change from a mixture of gases to a liquid ; and there is nothing 
 in this change that is equal to the spark. The cause of the 
 maintenance of the mercury in a Torricellian tube is the weight 
 of the air, and the weight of the air is certainly equal to the 
 weight of the mercury ; but the effect is not the weight of the 
 
 mercurv, but the maintenance of the height of the mercury, and 
 this cannot equal the weight of the air. As another instance of 
 equality of cause and effect, Professor Carveth Read says the 
 numbers of any species of plant or animal depend on the food 
 supply, and no doubt they do in part, but the numbers are not 
 equal to the food supply. The number of lions in a district is 
 not necessarily equal to the number of antelopes in that district ; 
 and if they were, the antelopes are not the cause of the lions. 
 Another instance of causation adduced by Professor Carveth 
 Read is still more to seek. * How learn to play the fiddle ? 
 Go to a good teacher (then, beginning young enough, with 
 natural ability and great diligence, all may be well).' I am at a 
 loss to discover how the cause in this case can be quantitatively 
 equal to the effect. No. I think the quantitative equality of 
 cause and effect is as idle a dream as the identity of cause and 
 effect : it is founded upon misapprehensions, and is not true, 
 
 nor even is it sense. 
 
 The next mark or character of causation is immediacy. The 
 relation of causation is said to be immediate, by which is meant 
 immediate sequence. Mr. Welton, as we have seen, confuses 
 immediate sequence with simultaneity. He takes it that an 
 effect which immediately follows a cause is simultaneous with 
 the cause, and from this he jumps to the further conclusion 
 that simultaneity means identity, so that an effect that imme- 
 diately follows the cause must needs be identical with the cause. 
 I do not think that either of these views needs serious refuta- 
 tion ; but the assumptionjhat_aneffect must necessarily follow 
 immediately on a causT^S^^^^-^^^^^ examination. 
 
 Certainly in common speech, and in the light of that common 
 sense which philosophers so much and so universally despise, 
 there is no such necessity ; nor is there any necessity in law. 
 If a man wounds another, and if that other dies of the wound 
 at any time within a year and a day of the assault, the assault 
 is in law the cause of the death, and the assailant may be guilty 
 of murder. Of course, philosophers are not bound to make 
 their definitions conform to the definitions of law ; but it is 
 very desirable that philosophers should not live wholly in a 
 balloon of speculation, out of all touch with mundane and 
 
ll 
 
 \ 
 
 i!i 
 
 ly 
 
 1.' 
 
 I 
 
 A 
 
 H 
 
 64 ON CAUSATION. 
 
 practical affairs. The use of opinion is to be a guide to con- 
 duct, a truth that philosophers rarely recognise ; and lawyers 
 have this advantage over philosophers, that their definitions 
 are perpetually being put to the test of practical use ; and if 
 they are found to be faulty from this point of view, the defini- 
 tion must be discarded or amended. Philosophers are under 
 no such obligation. They can, if they please, define *the 
 Knave of Hearts as the Jackovarts,' or that which depends on 
 conditions as unconditional, or sequence as simultaneity, or 
 simultaneity as identity, or causation as implication, or that 
 which cannot be perceived as a product of perception, or a battle 
 as a substance, and no one can prevent them ; nor are they under 
 any obligation to make their definitions square with their 
 practice ; but when one is immersed in practical affairs, and is 
 writing for the guidance of those whose business it is to discover 
 and record the causes of actual occurrences, it is prudent to 
 take into account the notions that are prevalent among men of 
 affairs, and not lightly to reject them. 
 
 The General Register Office is a department of the State 
 maintained at considerable expense, and engaged in collecting 
 and presenting to Parliament immense statistics of the causes 
 of death ; and the Registrar General has no hesitation in 
 admitting into his Tables, and presenting to Parliament, causes 
 of death that may have preceded the effect by weeks, months, 
 and years. Neither he, nor his staff of officials, nor the tens of 
 thousands of medical men who furnish him with items, nor the 
 High Court of Parliament, nor any of the multitude of scien- 
 tific men who have used these tables, have ever made any 
 objection to them on the score that the alleged causes of death 
 are not causes of death because the result does not immediately 
 follow on the cause. The Tables are not immaculate : they 
 are open to objection, as I shall presently show; but they are 
 of very great value to Officers of Health and others in the 
 prevention of disease, even though it is from time to time 
 found that some of the alleged causes of death are, after all, 
 not causes ; but if immediacy is a necessary element of causa- 
 tion, the alleged cause of death would be the true cause in 
 scarcely one of the millions of instances which the General 
 
 CAUSATION. 
 
 6s 
 
 Kegister Office has recorded ; and if the alleged cause were in 
 every case false, then the usefulness of the Tables would be 
 destroyed, and they would be of no value at all, either to Officers 
 of Health or to any other human being. The prima facie pre- 
 sumption against immediacy as a quality or mark of causation 
 is therefore very strong. 
 
 As I have shown in the previous discussion, immediacy in 
 the strict sense of the term cannot obtain in any case of effec- 
 tuation, for an effect is a change or an unchange, and an un- 
 change by its very nature implies duration, and cannot be 
 immediate; while in experience every change takes time, how- 
 ever short that time may be. Perhaps the nearest approach 
 to immediacy that we know is the effect of lightning upon our 
 mind the instant the flash passes ; but this we know takes 
 time — time for the light to travel to our eyes, time for it to 
 traverse the media, time for a change to take place in the 
 retina, time for an impulse to travel to the brain, time for it to 
 produce its effect there. Strict immediacy between cause and 
 effect is unknown to us ; but is not this pushing matters too 
 far ? May there not be a practical immediacy that is required 
 for causation, although immediacy in the pedantically accurate 
 sense there cannot be ? In other words, ought we not to limit 
 our notion of causation to that change which appears to our 
 senses to follow immediately upon an action, even though in 
 strict accuracy some infinitesimal fraction of a second may 
 separate them ? Well, as has already been shown, even in such 
 a restricted sense immediacy is not required in the current and 
 accepted meaning of causation ; and if it is to be imported into 
 the philosophical meaning, then philosophy cuts herself off, in 
 this respect, finally and for all from utility and common sense ; 
 and this is inadvisable if it can be avoided. But there is no 
 earthly reason why philosophy should thus make a fool of her- 
 self. One of the favourite maxims of logic is Nota notc^, nota ret 
 ipsius. As a logical maxim it is of little or no value, but in 
 the present connection it has this value, that it effectually 
 estops logicians from objecting to the maxim that I here pre- 
 sent to them : — Causa causes, causa rei ipsius. The cause of a 
 cause is the cause of the effect. 
 
 \ ' 
 
i 
 
 I'. 
 
 66 
 
 ON CAUSATION. 
 
 UavTa pu : all things flow. The universe is a series of con- 
 tinuous change. In this continuous series we may take, any- 
 where we please, a longitudinal section of any length we please, 
 and call the first change the cause of all or any that follow, and 
 the last the effect of all or any that have gone before : or we 
 can call the first the cause of the last, and the last the effect ot 
 the first. The process is familiar to us from childhood, and 
 was solved for us long before our infantine minds were sophis- 
 ticated by reading books on logic. If the cat began to catch 
 the rat, the rat began to gnaw the rope, the rope began to hang 
 the butcher, and so on until the pig began to get over the stile, and 
 the old woman reached her destination, then the action of the 
 cat was the cause of the rope being gnawed, of the butcher 
 being in peril of death, and of all the other events in succession 
 down to the old woman getting home in time. The cat's action 
 was the cause, immediately or mediately, of each effect, and it 
 was not less efficacious when it acted mediately than when 
 it acted immediately. It is just as scientific, and just as 
 philosophical, to attribute one man's death to the bite of a 
 mosquito twenty years before, as to attribute the death of another 
 to the explosion of a shell which blew him to bits in a moment. 
 
 The third distinguishing mark of causation is unconditional- 
 ness Mill invented the term, and gives, as is his custom, several 
 definitions of it, each different from the rest. It is synonymous 
 with necessitv ; it means whatever supposition we make about 
 all other things ; it means subject to no other than negative 
 conditions ; it means as long as the causes do not vary ; it 
 means, in short, pretty much what you please. Mill's discus- 
 sion of unconditionalness is a striking example of his utter 
 muddle-headedness. Invariable sequence, he says, is not syn- 
 onymous with causation, unless the sequence, besides being 
 invariable, is also unconditional, and this he says immediately 
 after he has defined the cause as ' philosophically speaking 
 the sum total of the conditions ! It is therefore philosophically 
 speaking conditional, and speaking otherwise unconditional. 
 This, however, is only a beginning. His fifth or sixth defini- 
 tion of a cause ' confines the meaning of the word cause to the 
 assemblage of positive conditions without the negative, and 
 
 CAUSATION. 
 
 67 
 
 then, instead of ** unconditionally " we must say " subject to no 
 other than negative conditions." ' So that in the first place the 
 cause is the sum of the conditions, both positive and negative ; 
 in the second place, it is the positive conditions without the 
 nec^ative ; and in the third place it is the negative conditions 
 without the positive. There is only one other possible alter- 
 native, that the cause is neither the positive nor the negative 
 ■conditions, and this, which is the correct view, is the only one 
 that Mill does not give. Hume is inconsistent enough, good- 
 ness knows, but Hume is a miracle of consistency in comparison 
 with Mill. * 
 
 Professor Carveth Read adopts unconditionality as a mark 
 of causation, and his meaning of the term is quite different 
 from any of Mill's, though he says it is what Mill means. 
 When Mill defines the cause of any effect as its unconditional 
 antecedent, he means, according to Professor Carveth Read, 
 that it is that group of conditions which, without any further 
 condition, is followed by the event in question. According to 
 this, when Mill said unconditional he meant un-further-condi- 
 tional ; and it is possible that Mill may have had sometimes in 
 his mind some such meaning as this ; but the only thing we 
 can be sure of is that what he meant at one time was not what 
 he meant at another time, and there is no evidence or indica- 
 tion that he had any definite meaning at all. However, there 
 are few writers on causation who do not adopt Mill's assertion 
 that it is unconditional, and all of those who assert that it is 
 unconditional assert, as Mill does, that it is conditional, and 
 never recognise the contradiction. They all identify or confuse 
 causes with conditions ; they most of them speak of the cause as 
 the sum-total of the conditions; and even a writer who owes so 
 little allegiance to Mill as Mr. Welton calls it the totality of the 
 conditions; and how that which depends upon conditions can be 
 unconditional, I confess I do not understand. I suppose Mill 
 must have had something in his mind when he said that to 
 constitute a cause the conditions must be unconditional, but 
 what it was we do not know, and whether Professor Carveth 
 Read is correct in his surmise that it was un-further-conditiona 
 vcannot now be known. Anyhow, to speak of that as uncondi- 
 
I ■• 
 
 
 68 
 
 ON CAUSATION. 
 
 .11 
 
 I 
 i 
 
 u 
 [V 
 
 tional which is on all hands admitted and proclaimed to be 
 subject to conditions seems to me an inadmissible abuse of 
 
 language. 
 
 The fourth of Professor Carveth Read's stigmata of causation 
 is invariability. Mill adopted the notion from Hume, and every 
 writer of that school pins his faith to invariability ; but when 
 we seek the meaning that they attach to the term, we find our- 
 selves in wandering mazes lost. Does it mean that the cause 
 is invariable ? or that the effect is invariable ? or that the cause 
 invariably precedes the effect ? or that the effect invariably 
 follows the cause ? As far as I can make out, sometimes one 
 and sometimes another, but most often none of these meanings 
 is intended. Mill varies in his statements about invariability 
 as in those about everything else. The most definite opinion 
 he gives is this : ' That we should believe not only that the 
 antecedent always has been followed by the consequent, but 
 that so long as the present constitution of things endures, it 
 always will be so.' It seems from this passage that ' invariably' 
 means, with Mill, ' always,' and I believe that this is the meaning 
 that his followers attach to it when they mean anything at all ; 
 but like their leader, they never keep long to the same meaning 
 of any important word or doctrine, and Mill himself, on the 
 very next page, says, * Invariable sequence ... is not 
 synonymous with causation unless the sequence, besides being 
 invariable, is unconditional.' 
 
 When it is said that the cause is the invariable antecedent, 
 what ought to be meant, though I doubt very much if it is 
 meant, is that the cause is that antecedent which does not vary. 
 If this is the meaning, it is doubly wrong, for in the first place, 
 a cause need not be an antecedent, and in the second, if it is an 
 antecedent it may vary, and usually does vary. If the ante- 
 cedent must not vary, then the pressure of the gas of an exploding 
 cartridge is not the cause of the propulsion of the projectile, for 
 the pressure of gas varies from moment to moment as the 
 projectile travels along the bore of the gun. 
 
 When it is said that the effect is the invariable consequent, 
 what ought to be meant, though I beheve it never is meant, is 
 that the effect is that c-onsequent which does not vary. If this 
 
 CAUSATION. 
 
 69 
 
 is the meaning, it is undoubtedly wrong, for an effect need not 
 be a consequent, and when it is a consequent, it may vary. If 
 the consequent must not vary, then the movement of a motor 
 car is not due to the action of the engine, for the speed varies 
 with the gradient, and with the surface of the road. 
 
 When it is said that causation is invariable sequence, what 
 ought to be meant is that the time and manner in which the 
 cause precedes the effect, or in which the effect follows the 
 cause, do not vary. But in the first place, causation need not 
 be sequence, and in the second, when it is sequence, it may 
 be variable. The time at which the report of a gun reaches us 
 does vary with our distance from the gun ; and the remittent 
 manner in which the light from the fixed stars reaches us varies 
 from the steady manner in which the light from the planets 
 
 reaches us. 
 
 But suppose, what I believe is the case, that writers on 
 
 causation express their meaning in this matter, as in other 
 
 matters, inaccurately, and when they say invariably they 
 
 mean always ; is it true that .there is no causation unless the 
 
 cause is always followed by the effect, and the effect is always 
 
 preceded by the cause? Then how if cause and effect are 
 
 contemporaneous, as they are in the causation of an unchange? 
 
 If sequence is always necessary to causation, then such un- 
 
 changes as the maintenance of the motion of a locomotive, 
 
 or the maintenance of animal life, or the suspension of a 
 
 weight by a cord, or the prolonged boiling of water, are not 
 
 caused. They are not effects, nor instances of causation. But 
 
 even supposing there is no causation except the sequence of 
 
 change on action, is it t ruelHaf there is no causation unless this 
 
 sequence always happe nsTn!^en h^ if it happens once only ? 
 
 Once, as the boy said to the man who declared that he was once 
 
 as active as the boy, 'Once ain't often.' Still less is it always. 
 
 If I see a bottle of wine fall on a stone floor and smash, am 
 
 I to denyjha^theJall_of that bottle on tojhe floor was the 
 
 cause pflHe smash? ""it ^^h^^ once and can 
 
 never happen again. * Oh, but,' says the logician, *when 
 
 similar bottles have fallen on ^stone floors they have always 
 
 broken.' Indeed ? I haveTtln mind that this very bottle 
 
;o 
 
 ON CAUSATION. 
 
 lil 
 
 .! 
 
 \( 
 
 had previously slipped out of my hand and fallen a sixteenth 
 of an inch on to the very same stone floor, and yet was not 
 broken. 'But then the cause was not the same, lor the 
 bottle did not fall so far.' Granted, but your definition says 
 nothing about the same cause, it says the cause is always- 
 followed by the effect ; and you now say that the cause ot 
 the bottle breaking was its fall for a certain distance; but 
 I had previously let that bottle fall the very same distance on 
 to a truss of straw, and the bottle did not break. ' Ah yes, 
 but when I say the same cause I mean the same cause acting 
 in the same conditions.' But if the same cause had acted m 
 the same conditions the bottle would have smashed betore, 
 and you cannot be always smashing the same bottle, you 
 know. It seems to me that cadit ampulla, cadU quctstw. But 
 may we never predicate causation until an event has occurred 
 repeatedly ? Then how often must it be repeated before we 
 can say it always has happened ? how often before we can 
 say it always will happen ? Suppose a man hits me in the 
 eye, how many times must I get him to repeat the blow 
 before I can be sure that it is the cause of my eye turning 
 black? ' But,' says the logician, 'a blow on the eye a ways 
 has been followed by the blackening of the eye, and always 
 mV/ be followed by the same phenomenon.' Has it? \Vhat 
 do you know about black eyes amongst Moustenan or Nean- 
 derthal men ? And will it? Why? ' Because the same cause 
 is invariably followed by the same effect.' 
 
 ' My friend,' I reply, ' you are a logician ; did you never hear 
 of the circulus in probanda ? ' . 
 
 I can imagine the tormented logician answering these 
 
 objections something in this way :— • • ui 
 
 'When I say invariably, of course I don't mean invariably ; 
 I mean always. At least I don't exactly mean always. You 
 are so confoundedly particular. You expect me always to 
 mean precisely what I say, and to say precisely what I mean ; 
 and you expect me always to have a precise meaning to 
 express. You forget that I am a logician. When I say the 
 effect invariably follows the cause, I mean of course that it 
 follows unconditionally, that is to say, in certain conditions. 
 
 CAUS.\TION. 
 
 71 
 
 'That,' I should answer, ' is a curious meaning for uncon- 
 ditionally ; but waiving that, what are these conditions ^ 
 
 'Whyf of course, the same conditions in which it happened 
 
 *'But ex hypothesi, it never has happened before.' 
 
 ' Weil then, the same conditions in which it would have 
 happened before if it had happened before.' 
 
 'Thank you verv much, but on your own showing, the same 
 conditions never are, and never can be repeated.' 
 
 ' Really, sir, I cannot bandy words further with a person 
 ^vho knows nothing of logic. Allow me to bring to your 
 notice the well-known philosophical principle, of which you 
 have never heard, that all reasoning is through a universal. 
 I wish vou a very good morning, and take my leave of you. 
 
 It would be difficult for me to suppress Hamlet s answer- 
 You cannot, sir, take from me anything that I more willingly 
 
 will part withal. , 
 
 No I am afraid invariability must go after equality and 
 imme'diacv and the rest of the marks that are supposed to 
 characterise causation, and- with them must go the las o 
 Professor Carveth Read's distinguishing marks of cause that 
 oi antecedence. It is manifest to everyone who is not wilfully 
 blind, that the cause of a change must be antecedent to the 
 effect even when cause and effect are apparently simultaneous. 
 The fracture of a glass bottle by the blow of a stick seems 
 to be instantaneous, and no doubt the time consumed is very 
 short But if the operation were photographed by a rapidly 
 moving kinematograph, and the film was to be put through 
 the lantern very slowly, we should see the glass yield and 
 bend before the pressure of the stick, and give way first on 
 the surface remote from the stick, and gradually spread until 
 it involved the whole thickness. We should see the splinters 
 separate, not simultaneously, but successively, and that the 
 whole operation took time. This, I think, is one answer to 
 Mr. Bertrand Russell's contention that we can divide up the 
 cause, or the duration of the cause, into many successive 
 instants, of which the last only is entitled to the name of 
 cause ; and that it is this last division only upon which the 
 
h 'I 
 
 72 
 
 ON CAUSATION. 
 
 CAUSATION. 
 
 73 
 
 I 
 
 h 
 
 I 
 
 effect follows instantly, and with which the effect is virtually 
 continuous. These are not his words, but this is the meaning 
 of his doctrine as I understand it. It is not so. The cause 
 has a certain duration; and during every instant of that 
 duration it is a cause, and is in action, and is causing more 
 and more of the effect. The effect also has a certain duration. 
 As the cause begins to act, the change begins to occur ; as the 
 cause continues, the change increases ; when the cause ceases, 
 the effect reaches its maximum. As soon as the cause ceases to 
 act, the effect, as an effect, that is as a progressing change, also 
 ceases, and becomes a result. The total effect is not reached 
 until the cause ceases to act, and it is in this sense, and in this 
 sense only, that the effect succeeds the cause, and that cause 
 and effect are antecedent and consequent. 
 
 But when the effect is an unchange, the cause does not and 
 cannot precede, nor can the effect follow. In this case cause 
 and effect are contemporaneous ; the only exception, which is 
 but an apparent exception, being the delay due to inertia in the 
 starting and cessation of that unchange which is the motion of 
 a body, such as a cart, a motor car, or a railway train, that owes 
 its motion to continuous action. 
 
 What, then, is the quality which characterises and marks 
 causation ? It is not at all difficult to discover, and indeed it 
 was discovered and assigned long before the day of Hume, but 
 he took a violent prejudice against it, and all his successors 
 have been afraid of it. They have avoided it as if it were an 
 asp or a viper, and few of them even dare to mention it ; and 
 yet there is nothing frightful about it, and if the nettle is firmly 
 grasped, it not only fails to sting, but even furnishes a grateful 
 and sufficient support. 
 
 Daily the tide rises on our coasts, and daily thereafter men 
 and women in this country marry ; and in some respects the 
 consequents are invariable. They invariably marry two at a 
 time and with some sort of ceremony. Moreover, this conse- 
 quence always follows the antecedent : not a rise of the tide 
 occurs but some marriage follows it. As far as history goes 
 back, this consequent has always followed this antecedent ; as 
 far as we can foresee, the consequent will follow the antecedent 
 
 ^ as long as the present constitution of things endures ' ; and 
 these are the conditions that are said to convert mere time- 
 sequence into causation. But they don't. No one but a lunatic 
 or a logician would regard the rise of the tide as the cause of 
 men and women marrying ; and why not ? Ask the first man, 
 woman, or child (not being a lunatic or a logician) you may 
 4:ome across why they do not regard the rise of the tide as the 
 cause of marriage, and he, she, or it will answer ' Because there 
 is no connection between them.' This is the obvious answer, 
 and it is a very good answer as far as it goes, though it is not 
 quite a sufficient answer. 
 
 There are two reasons why it is not quite a sufficient answer : 
 first, because things may be connected together in sequence 
 without being cause and effect, and second, because it does not 
 explain the nature of the connection. 
 
 Night ahvays follows day, and the two are connected, but 
 yet night is not the effect of day. The flight of the projectile 
 always follows the recoil of the gun, and is connected with it, 
 but the recoil of the gun is not the cause of the flight of the 
 projectile. The sinking of the stone always follows the splash, 
 and is connected with it, but the splash is not the cause of 
 the sinking of the stone. Although, however, these instances 
 prove that mere connection in sequence does not constitute 
 causation, even when the sequence is constant (which is what 
 logicians mean by invariable) yet it is clear in each case that 
 the connection in sequence does depend upon causation. The 
 connection between day and night is that they have a common 
 cause, the rotation of the earth. The connection between the 
 recoil of the gun and the flight of the projectile is that they 
 have a common cause, the explosion of the charge. The con- 
 nection of the sinking of the stone with the splash is that they 
 have a common cause, the fall of the stone into the water. 
 It is evident that we are getting 'warm.' If the connection 
 between antecedent and consequent does not itself constitute 
 causation, yet it is evident that it is indispensable to causation, 
 and that we may say provisionally 
 
 Causation is the connection between cause and effect. 
 
 Although, however, this is true, it does not carry us much 
 
74 
 
 ON CAUSATION. 
 
 CAUSATION. 
 
 75" 
 
 il^ 
 
 forwarder. It does not display the nature of the connection. 
 In order to get a complete definition of causation, and to clarify 
 the concept, we must substitute for the terms cause and effect 
 the definitions of them at which we have previously arrived. 
 We shall then get the following definition : — 
 
 Causatioi is the connection between an action and the following 
 change or accompanying tmchange in the thing acted on. 
 
 If we apply this definition to the foregoing test cases we find 
 that it fits, and satisfactorily explains why they are not cases 
 of causation although they are causally connected. Night 
 always follows day, and is connected with it ; but night is not 
 the effect of day, and why not ? Because, although there is a 
 connection between them, the connection is not between an 
 action and a change in the thing acted on. Day does not act 
 upon anything to cause night. The recoil of the gun always 
 precedes the flight of the projectile, and is connected with it ; 
 but the recoil of the gun is not the cause of the flight of the 
 projectile, and the reason is manifest— the recoil of the gun does 
 not act on the projectile, the thing in which the effect is pro- 
 duced. Similarly, the reason the splash is not the cause of the 
 sinking of the stone is that the splash does not act upon the 
 stone, the thing in which the change occurs. 
 
 The same formula satisfies all Mr. Welton's diflicult cases. 
 ' The dryness of a boy's clothes before his immersion in water 
 is not the cause of their subsequent wetness.' It certainly is 
 not, and I doubt if even a logician has ever suggested that it is; 
 * that cause can only be found in that spatial relation between 
 the clothes and the water which we call contact.' It is true that 
 we may speak of the contact of the water with the clothes as 
 the cause of the wetness of the clothes, but what we mean, or 
 ought to mean, by contact, in this case, is not being in touch, 
 but bringing into touch. The cause of the wetness of the 
 clothes is the action of bringing water into contact with them, 
 and then the action of water upon them. Once the clothes are 
 wet, the continued contact of the water with them is not the 
 cause of their wetness, it is their wetness. The bringing of the 
 water into contact with the clothes is the cause, the effect is not 
 wetness, it is becoming wet. Wetness is not an effect, it is a 
 
 result. Mr. Welton's statement is vitiated by two confusions. 
 He says wetness when he means becoming wet, and he says 
 contact when he means bringing into contact. 
 
 * A dropping of ink upon paper causes a blot, but the blot is 
 there as soon as the contact of ink and paper is made ; it is that 
 contact.' Here again there is confusion. The dropping of the 
 ink upon the paper is rightly called the cause of the blot, for 
 the dropping of the ink is an action on the paper, and the blot 
 is the change in the thing acted on, and is connected with the 
 action. It is true that the blot is there as soon as the contact 
 is made, as every effect is there as soon as the causing action is 
 complete ; but I see no ground for asserting that the blot is the 
 contact. As well might we say when a man lies in bed, that the 
 contact of the man with the bed is the man. The blot is not the 
 contact. The blot is the layer of ink adhering to the paper. 
 
 There is yet one thing wanting to the definition of causa- 
 tion. It is, we find, the connection between an action upon a 
 thing and the sequent change or accompanying unchange in 
 that thing; but we have yet to ascertain the nature of the con- 
 nection. This cannot be put much better than in the words in 
 which Hume stultifies his whole previous argument, — ' where, 
 if the first object had not been, the second had never existed.' 
 In other words, the connection is a necessary connection. 
 Much superfluous verbiage has been wasted in discussing the 
 nature of necessity, which is perfectly clear to everyone but 
 philosophers. By necessary connection I mean that the action 
 is so connected with the change or unchange that if the action 
 had not taken place, the change or unchange w^ould not have 
 occurred ; and the action taking place in the conditions in which 
 it did, the change or unchange connected with it was unavoid- 
 able and unpreventable. That, I believe, asserts the true 
 nature of causation, which may be finally defined thus : — 
 
 Causation is the necessary connection between an action and the 
 sequent change or accompanying nnchange in the thing acted on. 
 
 Mill boggles at the term necessary, and suggests that its 
 meaning is not clear. ' If,' he says, ' there be any meaning 
 which confessedly belongs to necessity, it is nnconditionalness,' 
 and thus he substitutes for a plain clear word w^hich everyone 
 
 ! i 
 
ii 
 
 ■s 
 
 Ii I' 
 
 i. 
 
 76 
 
 ON CAUSATION, 
 
 '1^ 
 
 understands, a word which no one else understands, and which 
 he does not understand himself. What he means by 'con- 
 fessedly ' it is difficult to surmise, for no one but himself has 
 €ver defined necessity as unconditionalness, and not even his 
 followers confess that they mean the same thing. It is another 
 of his wandering and unwarrantable assertions, adopted, ap- 
 parently, on the spur of the moment, without consideration or 
 justification. No one has ever confessed that necessity means 
 unconditionalness ; and it doesn't. Whichever of Mill's various 
 definitions of unconditionalness we adopt, it bears no resem- 
 blance to necessity. 
 
 But is causation the necessary connection that I have asserted 
 it is ? It may be said that if the severing of an artery which 
 causes a man's death had not taken place, the death would still 
 have occurred sooner or later, and therefore the connection 
 between the cause and the effect was not necessary. The 
 obvious answer is that though the connection between the 
 severing of the artery and the death of the man was not neces- 
 sary, the connection of the severing of the artery with his 
 death by hemorrhage at that time and place was necessary. 
 It was necessary to that particular effect. And it may be said 
 that the death did not necessarily follow, for if a surgeon had 
 been present, and had tied the artery, the man would not then 
 and there have died, so that the change was neither unavoidable 
 nor unpreventable ; and this is true, but then the conditions 
 Vv'ould not have been the same. The conditions being what 
 they were, the change followed necessarily, in the sense in 
 which I have defined necessarily, on the action ; and it is this 
 necessary connection between the cause and the effect that 
 constitutes causation.^ 
 
 * A doubt, I find, is felt by a reader, whether the maintenance of the motion 
 of a locomotive can properly be called an unchange ; for it may be said— Are not 
 all parts of the machinery continuously changing in position r Animal life also is 
 a perpetual series of changes ; how then can it be called an unchange ? The 
 answer is that the nature of things as it appears to us, and as for our purposes it 
 is, varies according to the way in which we choose to contemplate them. An 
 unchange, as I have defined it, is a way of contemplating things, just as a class is 
 a way of contemplating things. No such thing as a class exists except in our 
 minds. When several individual things have some quality in common, such as 
 hardness, or whiteness, or motion, we may mentally group them together, and 
 contemplate th«m together as all possessing that quality; and by the possession 
 of that quality they are grouped together in our minds, and consolidated into a 
 
 CAUSATION. 
 
 Summary. 
 
 77 
 
 This chapter examines the five characters or marks that are 
 said to be characteristic of causation, viz., equality of cause 
 and effect, immediacy, unconditionality, invariability, and 
 antecedence ; and shows that not one of them properly or 
 necessarily pertains to causation. 
 
 By successive approximations the definition is reached that 
 Causation is the necessary connection between an action and 
 the sequent change or accompanying unchange in the thing 
 acted on. 
 
 The meaning of ' necessary ' in connection with causation is 
 defined. 
 
 single object of contemplation — a class of hard, or white, or moving things. They 
 are not grouped together in fact, or outside of our minds. Both the North Pole 
 and the South Pole are white, and may be contemplated together as adjoining 
 white things in the class of white things ; but in fact they do not adjoin, but are 
 wide asunder. To call things a class is to contemplate them together ; and to 
 separate them, not actually, but in contemplatioo, from other things that have not 
 the class-quality. Just in the same way, we may take all the successive changes 
 of a locomotive, both the internal changes of its parts, and the changes of position 
 of the whole with respect to its surroundings, and contemplate them all together, 
 as grouped and consolidated into a single object of contemplation, which we call, 
 not a class, but an unchange. We call it an unchange, or the maintenance of an 
 unchanging state, because, as movement, it does not change to rest, although there 
 are forces in action — friction, gravity, and so forth — tending to bring it to rest. 
 Each movement of the parts is a change, and may be so contemplated if we 
 choose J but we need not so contemplate it. The movement of the whole is 
 change of place with respect to surroundings, and may be so contemplated ; but it 
 need not be so contemplated. We may, if we please, regard the movement, not in 
 contrast with surrounding things which remain at rest, but in contrast with its own 
 possible state of rest, or in contrast with its being brought to rest, which would be 
 a change of another kind, but still a change. So contemplated, the state of motion 
 is not a change, but the maintenance of the unchanging state of motion. In short, 
 it is an unchange. 
 
SUBSIDIARY PROBLEMS. 
 
 I 
 
 79 
 
 
 f, 1 
 
 CHAPTER V. 
 SUBSIDIARY PROBLExMS. 
 
 I. Plurality of Causes. 
 
 Mill is the inventor of the phrase Plurality of Causes, and he 
 gets into his usual muddle over it, a muddle which even his 
 followers have discovered to be a muddle, but which they have 
 only partially cleared up. It will be remembered that one of 
 his statements of the Law of Causation is * that every conse- 
 quent is connected in this manner [invariably] with some 
 particular antecedent, or set of antecedents. Let the fact be 
 what it may, if it has begun to exist, it was preceded by some 
 fact or facts with which it is invariably connected.' It would 
 be difficult to put the statement more positively or more 
 strongly, and as he himself would say more unconditionally. 
 It is an unqualified assertion ; and yet in a subsequent Chapter 
 he says ' There are often several independent modes in which 
 the same phenomenon could have originated. . . . Many causes 
 may produce mechanical motion : many causes may produce 
 some kinds of sensation i^ many causes may produce death.' 
 Inconsistency is, as I have said elsewhere, with other people a 
 vice to be avoided. With logicians it is an end to be pursued 
 for its owm sake. A writer on any other subject who should 
 thus stultify himself by self-contradiction would be discre- 
 dited, but with logicians self-contradiction is rather a virtue 
 than otherwise. 
 
 It is clear that in this use the term Plurality of Causes is 
 
 Avrong, and doubly wrong. In the first place it does not mean 
 that any single instance of effect is due to more than one cause, 
 and in the second it does not mean that more than one cause 
 may be necessary to produce a certain effect. What is meant 
 is that an effect of a certain kind may be due on one occasion 
 to one cause and on another occasion to another cause. This 
 is not Plurality of Causes: it is Alternity of Causes, or, as Pro- 
 fessor Carveth Read calls it, Vicariousness of Causes. When 
 an effect is said to be due to a plurality of causes, what is meant 
 is that if several effects resemble one another in some particular, 
 one may be due to one cause and another to another. The 
 death of A by drowning is due to one cause — drowning — and 
 no more. It is not due to a plurality of causes. The death of 
 B by shooting is due to a different cause, it is true, but then 
 it is a different effect. It is a different effect, occurring on a 
 different occasion, under different circumstances, to a different 
 person. Both effects include the element or ingredient of 
 death, but the effects are not death, but deaths ; and when it 
 is said that many causes may produce death, what is meant is 
 that many different causes may produce many different deaths ; 
 which is not so very paradoxical. 
 
 When Mill said many causes may produce some kinds of 
 sensation, we may suppose that what he had in his mind was 
 sound, which is a kind of sensation. But sound in general is 
 not an effect : it is a generalisation from many individual 
 instances of sound, each of which was an effect, and an effect 
 of one single cause. Mill's blunder consists in generalising 
 the effects without generalising the causes. If we generalise 
 mxany instances of sounds into the one concept of sound, and 
 call the generalisation a single effect, we should also generalise 
 the causes of all these sounds, and call the common ingredient 
 in them the cause of sound. Each separate sound will then 
 have its separate cause ; and the common ingredient in them 
 all will have its common cause in aerial vibration. Similarly, 
 if we generalise the common ingredient in many deaths, and 
 call it death, we must generalise the common ingredient in all 
 the causes of these deaths and call it cessation of the heart's 
 action. There is no such thing as Plurality of Causes in 
 
 .i. 
 
r\ 
 
 80 
 
 ON CAUSATION. 
 
 SUBSIDIARY PROBLEMS. 
 
 81 
 
 1 1 
 
 h 
 
 Mill's sense, unless we generalise the effects while leaving" 
 the causes particular, which is not a very legitimate logical 
 
 operation. 
 
 It is of course perfectly legitimate, and may be very useful,, 
 to investigate ail the cases in which effects have a common 
 ingredient, such as deaths, or sounds, and to determine as 
 many as we can of the combined causes and conditions by 
 which the effects are produced that have this common ingre- 
 dient : this is very proper, and may be very useful ; but in such 
 cases we are seeking the causes, not of an effect, but of a 
 common ingredient in many effects ; and the plurality of causes 
 applies to the plurality of effects, and not to the common 
 ingredient in them, although for the sake of brevity and con- 
 venience we may allow ourselves to speak as if it did. In any 
 case, Plurality of Causes is clearly a misnomer here ; what is 
 meant is not Plurality of Causes but Alternity of Causes. 
 
 There is a sense in which plurality of causes is a perfectly 
 justifiable expression. There is a sense in which every event 
 has many causes, innumerable causes, and there are certam 
 effects that admit, and others that require, the cooperation of 
 more than one cause to bring them about. These we will 
 examine in their turn. 
 
 II. The Regression of Causes and the Progression 
 
 OF Effects. 
 
 A cause is an action in certain conditions upon a thing : 
 an effect is a change or unchange in the thing acted on, and 
 leads to a result. In the physical world, action means the 
 transfer or liberation of energy. It is now a commonplace 
 that energy neither appears out of nothing nor disappears 
 into nothing, but that every manifestation of energy is the 
 release of energy from store or its transfer from one thing to 
 another. If it is expended from store, then at some past time 
 it must have been put into store by some action or other. If 
 it is transferred from place to place, such transfer is action, and 
 action was as necessary to put it into the place from which it 
 comes as to put it into the place to which it goes. In short. 
 
 action, which is cause, is also always either effect or result. It 
 is always produced by previous action. 
 
 The action of the pig in getting over the stile was caused 
 l3y the action of the dog in biting him. The action of the dog 
 "was caused by the action upon it of the stick. The action of 
 the stick was caused by the action of the fire, which was caused 
 by the action of the water, which was caused by the action of 
 the ox, which was caused by the action of the butcher, and so 
 back to the action of the cat. There was a continuous regres- 
 sion of causes from the last effect to the first action ; and a 
 continuous progression of effects from the first action to the 
 last effect. 
 
 What is true of this dramatic and perhaps fictitious series is 
 true of every other case of cause and effect. The actions 
 stretch backwards in series as far as we like to trace them, or 
 can trace them ; and the effects proceed forwards down to the 
 present moment in which, as actions, they are carrying on the 
 chain of effects into a futurity of indefinite duration. 
 
 The motion of a train is the effect of the action of the wheels 
 upon the rails, which is the effect of the action of the piston- 
 rods on the cranks, which is the effect of the expansion of 
 steam in the cylinders, which is the effect of heat upon the 
 water in the boiler, which is the effect of the combustion of the 
 coal, which is the effect of the action of the fireman in lighting 
 and stoking, which is the effect of the action of his immediate 
 superior in giving the order, which is the effect of the action of 
 his superior, and so back to the directors, whose action is deter- 
 mined by the action of the travelling public in demanding 
 means of travelling, which is determined in the long-run by the 
 action of their predecessors in building up the complicated 
 structure of the nation with its needs for travel ; and so we 
 might, if we had the knowledge and patience, pursue the series 
 of actions back to the time when men first wandered into this 
 country, to the time when men first were, to the beginnings of 
 life, to the beginnings of the solar system, and further back ad 
 infinitum. In this long precession every action was caused by 
 some previous action, and produced, as its effect, a subse- 
 quent action; and the same is true of every other cause of 
 
 6 
 
Hi 
 
 82 
 
 ON CAUSATION. 
 
 SUBSIDIARY PROBLEMS. 
 
 33 
 
 > 
 
 change and of every other change. Action once taken goes on 
 producing its effects in succession for ever. 
 
 It is a commonplace that the institutions of a nation are 
 the results of the past history of that nation. The Napoleonic 
 wars, the Revolution, the revocation of the Edict of Nantes,. 
 the Great Rebellion, the discovery of America, the Hundred 
 Years' War, the Norman, Saxon, Danish, and Roman invasions,, 
 have each and all contributed to making our institutions what 
 they are, and to making us what we are. If Julius Caesar had 
 aot invaded Britain, I should not now be writing on the 
 Regression of Causes, and should probably never have been 
 born. 
 
 It is evident, therefore, that although the phrase * Plurality 
 of Causes/ in the sense in which Mill used it, was a misnomer, 
 and rests upon a confusion of thought, yet there is a sense in 
 which every effect has a plurality of causes — has an indefinitely 
 great multitude of causes, stretching back in continuous series. 
 to infinity of past time. 
 
 III. The Radification of Causes. — Indirect Causes. 
 
 There is more than this, however. The series is not the 
 simple series that has just been sketched. It is a complicated 
 web of infinite intricacy. To take a very simple case, the 
 birth of every child is the effect, and the child is the result, 
 of the actions of its two parents. Two actions were necessary 
 to the production of the effect. The birth of each of these 
 parents was the effect of similar actions on the part of the 
 grandparents, and the parents are the results of these actions, 
 so that in the second generation upwards there were four 
 causes. In the third there were eight, in the fourth sixteen, 
 and at every step backwards, with every preceding generation, 
 the number of causes increases in geometrical progression until 
 it is controlled by the intermarriage of descendants of the same 
 pair. But for this, the number of causes, even in historical 
 times, would be unimaginably great. 
 
 It is the same with all other effects. An effect is produced 
 by action upon a certain thing in certain conditions ; and for 
 the production of the effect, the thing and the conditions are 
 
 just as necessary as the action that is the immediate cause. 
 This thing and these conditions are themselves the results of 
 causes, which are therefore also necessary to the effect. In 
 order to produce the discharge of a gun, it is necessary to pull 
 the trigger. This action is the cause of the discharge. It is 
 the direct and approximately immediate cause; but every 
 action that went to build up the conditions necessary for the 
 discharge was a cause, more or less remote, more or less 
 indirect, of the discharge. A necessary condition of the 
 discharge is that the hammer should be at full cock. The 
 action of cocking the gun was the direct and immediate cause 
 of this result, and as the result is a condition of the discharge, 
 the cause of this condition is a cause of the discharge ; an 
 indirect cause, but still a cause, and a cause not very remote. 
 Anyone who is accustomed to scrutinize carefully the meaning 
 of words must feel a certain incongruity in speaking of the 
 cocking of a gun as the cause of its discharge ; but I think 
 that the incongruity is much diminished, if indeed it is not 
 altogether removed, but calling it an indirect cause. We may, 
 I think, formulate the following definition : — 
 
 An Indirect Cause is a cause of a condition. 
 
 Though the trigger is pulled with the hammer at cock, the 
 gun will not be discharged unless it is loaded. The presence 
 of the cartridge in the barrel is a condition of the discharge 
 and the action of loading the gun is the cause of the gun 
 being loaded, a result which becomes, with respect to the 
 discharge, a condition of the effect. The cause of this result, 
 the loading of the gun, is therefore another indirect cause of 
 its discharge. 
 
 It is a condition of the discharge of the gun on the pulling 
 of the trigger that the mechanism of the lock should exist in 
 good order : and the actions of making the lock, nay, on the 
 same principle, all the actions involved in making the gun, 
 are indirect causes of the discharge of the gun. There is 
 more than this, however. The gun is made of certain 
 materials; and the existence at hand of these materials is 
 a necessary condition of making the gun. The actions by 
 which these conditions were brought about, by which the 
 
^4 
 
 ON CAUSATION. 
 
 SUBSIDIARY PROBLEMS. 
 
 85 
 
 materials were made, prepared, and collected, are all indirect 
 causes of the discharge of the gun, and causes that are not 
 only indirect, but remote also. And so we may go back to 
 the growth of the tree of which the stock was made, to the 
 deposit of the ore from which the metal was extracted, to 
 the covering by alluvium of the forests which became the 
 coal wherewith the ore was smelted, to the growth of these 
 forests, and as much further back as we please. All these are 
 causes, more and more remote, more and more indirect, of the 
 discharge of the gun. 
 
 The action of pulling the trigger is a direct cause of the 
 discharge of the gun, but it is not the only direct cause. The 
 pulling of the trigger caused the fall of the hammer, which 
 caused the explosion of the detonator, and each of these actions 
 was a direct cause of the discharge of the gun. The soldier 
 had orders to fire as soon as the enemy should come within 
 a certain distance. The action of the officer in giving 
 the order was a cause of his pulling the trigger, and so a 
 direct, but a mediate cause of the discharge of the gun. The 
 action of the enemy in coming within the stated distance 
 was another direct cause, but a mediate cause, of the dis- 
 charge ; and all the actions that led up to these causes were 
 causes of the discharge itself, direct causes, but causes more 
 and more remote as the number of actions between the cause 
 and the ultimate effect increases. Thus we may carry the 
 line of direct causes back, through the orders of intermediate 
 officers on both sides to those of the generalissimos ; to the 
 causes of the war ; to the multitudinous actions of the members 
 of the nations at war that produced their antagonism; and 
 so on. We have already seen that at a very early stage the 
 line of direct causes divides into two, the actions of the 
 soldier's superiors on the one side, and the actions of the 
 enemy on the other ; and it would be easy to show that 
 at each step backwards the causes multiply like the ancestry 
 of every individual man, until at length they become unimagi- 
 nably multitudinous. They still remain direct causes, however 
 remote they may become, as long as aation produces action, and 
 the line is not interrupted by the interposition of a condition. 
 
 It is manifest from these examples that both the direct and 
 the indirect causes ramify, or rather radify (for causes are 
 evidently rather the roots than the branches of effects), as 
 we go backwards from the effect; and that the further back 
 we go, the more numerous they become. The conditions 
 may be many, and each may have many causes, depending 
 on other conditions, which again may be many, and so on. 
 The direct causes go back in series to an indefinitely remote 
 past ; and not in single series, but in series that spread like 
 the spokes of a fan, and that divide and redivide and radify 
 indefinitely. 
 
 Yet out of all these different series of innumerable causes, 
 both direct and indirect, it is usual to select one, and to call 
 it the cause. On what principle is this selection made ? What, 
 for instance, is the cause of the kettle boiling over? The 
 action of the fire, says the master. Leaving the kettle toe 
 long on the fire, says the mistress. The neglect of the 
 kitchenmaid, says the cook. The cook sending me upstairs, 
 says the kitchenmaid. The cook's forgetfulness in leaving 
 her apron upstairs, says the housekeeper. Every one of them 
 is right. Each of these is a cause ; but which is the cause ? 
 
 It may seem that, strictly speaking, we should limit the 
 cause to the direct immediate cause, to the action that is 
 nearest to the effect and immediately precedes it ; as for 
 instance, in the case of the discharge of the gun to the pulling 
 of the trigger. But we find upon trial that this will not do. 
 In fact we very often assume, as the cause, an action that 
 by no means immediately precedes the effect ; and in fact we 
 often do not know the immediate cause, and when we do 
 know it, we often do not take it into consideration. It seems 
 at first blush that the pulling of the trigger is the immediate 
 cause of the discharge of the gun, but a moment's thought 
 shows that it is not. Between the immediate cause and the 
 effect nothing can intervene, nothing can interpose ; but the 
 trigger acts through the medium of the mechanism of the 
 lock, and if this mechanism is impaired the discharge may 
 not follow. After passing through the mechanism of the lock 
 the action must reach the hammer, and cause it to fall; and 
 
S6 
 
 ON CAUSATION. 
 
 SUBSIDIARY PROBLEMS, 
 
 S7 
 
 the action of the hammer is more nearly immediate than that 
 of the trigger. The fall of the hammer strikes the detonator, 
 bat even this is not quite immediate, for the detonator may 
 not explode. The truly immediate cause of the discharge is 
 the explosion of the detonator, but this is never spoken of as 
 the cause of the discharge, and is rarely thought of as the 
 cause. We may put immediacy on one side, therefore: it 
 does not determine us in fixing on the cause. Even apparent 
 immediacy does not determine us, for we may as legitimately 
 look upon the order to fire as the cause of the firing as the 
 pulling of the trigger. What then should, and what does 
 determine us in fixing upon one among the innumerable causes 
 of an effect, and calling it the cause ? 
 
 It depends entirely upon the purpose in view, that is, upon 
 the aspect of the matter in which we are interested. The 
 master, the mistress, the cook, the kitchenmaid, and the house- 
 keeper are each of them right about the cause of the kettle 
 boiling over, but they all look at it from different points of 
 view, and for different purposes. The master looks at the 
 matter from the point of view of the physicist, and to him the 
 cause is the physical cause, which happens also to be the 
 immediate cause. The women all look at the matter from the 
 point of view of responsibility, and for the purpose of fixing 
 the responsibility. According to the mistress, the cause was 
 such that someone was responsible. The cook seizes upon the 
 cause that makes the kitchenmaid responsible. The kitchen- 
 maid selects the cause that throws responsibility upon the 
 cook ; and the housekeeper chooses the cause that not only 
 supports the kitchenmaid but throws a double measure of 
 responsibility on the cook. 
 
 During shooting at the butts, a trespasser gets into the line 
 of fire, and is killed by a bullet. What is the cause of his death ? 
 That depends entirely on the point of view and the purpose of 
 the person who makes the enquiry. To the physiologist it is 
 arrest of the heart's action ; to the pathologist it is the effusion 
 of blood round the heart which stopped the heart's action ; to 
 the student of ballistics it is the low trajectory of the bullet ; 
 to the marksman it was the force of the wind, which deflected 
 
 the bullet from the line of aim ; to the ammunition expert it is 
 the issue of the new light bullet, which yields more to the force 
 of the wind than the men are accustomed to ; to the squad 
 instructor it was the failure of the marksman to respond 
 promptly enough to the order ' Cease fire ' ; to one leader- 
 writer it is the deplorable carelessness of the soldier; to another 
 it is the stupidity of the civilian in crossing the line of fire ; and 
 so we could go on multiplying causes ad infinitum. The fact is 
 that everyone of these may quite legitimately be considered a 
 cause, but if we ask which is the cau se it is evidently quite im- 
 possible to reply until we know for what purpose the question 
 is asked. Is it to fix responsibility ? Is it to prevent similar 
 effects in future ? Is it to determine the mode of flight of the 
 new bullet ? Is it to clear up a nice point in pathology ? It 
 may be any of these, and according to the purpose of the argu- 
 ment will be the answer to the question What was the cause ? 
 
 IV. The Cooperation of Causes. 
 
 Every effect is, as we have seen, the product of a long and 
 complicated web of causes stretching back into infinity, all 
 of which are necessary to produce the effect ; and therefore 
 every effect is in a sense due to a cooperation of causes. There 
 are, however, cases in which an effect is due in a special sense 
 to a cooperation of causes. We have found that it is a fre- 
 quent and a legitimate practice to single out one of the 
 multitude of causes to which a given effect is due, and to 
 call that the cause, which it is from a certain point of view, 
 and for a particular purpose. We call it the cause, because 
 It IS that one of the causes in which we are for some purpose 
 interested, and because on that account we allow our con- 
 templation to rest upon it to the ignoring of the rest. Just in 
 the same way, and for a purpose, we may select from a series 
 •of causes a certain length of the series, comprising a certain 
 number of successive causes, and limiting or extending our con- 
 templation to them, we may regard them as in a special sense 
 the causes of the effect ; and in such a case we regard them as 
 cooperating more closely and more specially with one another 
 
 I 
 
 I 
 
 s 
 
i H 
 
 88 
 
 ON CAUSATION. 
 
 to produce the effect than the other causes, which, for the pur- 
 pose in hand, we leave out of our consideration. Or two actions 
 may simultaneously take place on one body, so that the changes 
 they severally produce are merged and blended in a single 
 change; and then we naturally contemplate them in association 
 with each other, and regard them as cooperating to produce that 
 change. Every effect is in fact due to the cooperation of many 
 causes, direct and indirect, immediate and remote ; but according 
 to the purpose in hand we limit our contemplation to one, two, 
 
 or a limited number. 
 
 Thus regarding them, we may make several classes of co- 
 operating causes, according, first, as the causes we consider are. 
 like or unlike, and second, as they operate successively or simul- 
 taneously. 
 
 Cooperation of Like Causes in Succession, 
 An instance of like causes cooperating in succession to pro- 
 duce a certain effect is seen when a nail is driven home by 
 repeated blows of a hammer. Each blow produces a certain 
 effect on the nail, and drives it further in. In a sense, and 
 from one point of view, it is the final blow only that drives the 
 nail home ; but if it is more convenient for any purpose to con- 
 template the operation as a whole, then we may regard, not 
 each blow as driving the nail for a certain distance, but the 
 whole series of blows as causes cooperating in producing the 
 complete effect of driving the nail home. 
 
 Actions may be like in kind though they are unlike in sign. 
 The action of paying money into the bank is like in kind to the 
 action of drawing money out of the bank, since they are 
 both transfers of money with reference to the bank ; but 
 they are unlike in sign, the one kind adding to the balance 
 and the other diminishing it ; but the two causes cooperate in 
 succession to bring about the result, the amount of the bank 
 balance. 
 
 Simultaneous Cooperation of Like Causes. 
 The flow of a large body of water from the upper reaches of 
 a tidal river may coincide with an unusually high tide to pro- 
 
 SUBSIDIARY PROBLEMS. 
 
 89 
 
 duce in the lower reaches a flood, that would not have occurred 
 but for the simultaneous cooperation of the two causes. The 
 simultaneous rush of all the passengers to the side of the boat 
 may cooperate to make the boat capsize. If a bullet or a bird 
 flies across in front of a photographic camera at the moment 
 the shutter acts, an image of the flying object will be formed 
 upon the plate. If the actions are not simultaneous, no such 
 effect will be produced. 
 
 Indifferent Cooperation of Like Causes, 
 
 Like causes may cooperate to produce an effect or a result 
 independently of whether they act successively or simulta- 
 neously. If one force acts upon a body so as to move it to the 
 north, and another equal force acts upon it for an equal time 
 so as to move it to the east, the effect will be that the body will 
 reach a certain point to the north-east, which will be the same 
 whether the forces act simultaneously or in succession. If we 
 add the two components of a Seidlitz powder to a glass of 
 water, the effect is the same whether we add them simulta- 
 neously or successively. 
 
 Successive Cooperation of Unlike Causes. 
 
 When unlike causes cooperate in succession to produce an 
 effect, it is almost always necessary that they should operate in 
 a certain order ; and unless this order of succession is strictly 
 observed, the effect will not be produced. The great majority 
 of effects and results that are produced by human agency are 
 of this class. When a thing is to be made, the materials must 
 first be provided, and then one operation after another is fol- 
 lowed in a certain order, and the effect and the result are looked 
 upon as due to the cooperation of all these processes. When 
 bread is to be made, the flour and water are first provided, 
 then the dough is mixed, then it is leavened, then kneaded, 
 then allowed to rise, divided, and baked ; and these operations 
 must follow one another strictly in this order if the effect is to 
 be produced. The final effect, the production of bread, is due 
 to the cooperation of the various causes in orderly succession. 
 
90 
 
 ON CAUSATION. 
 
 ^1 
 
 If any one is omitted, or done out of its turn, or bungled, the 
 effect is spoilt, the result is a failure. And so whenever any- 
 thing is made by art of man, it is made by certain actions in 
 orderly succession, and the whole series of actions cooperate 
 to produce the thing made. There is actually no break in the 
 long chain of causes, direct and indirect, stretching back in- 
 definitely into the past ; nor in the long chain of effects and results 
 stretching forsvard from the moment the thing was made ; but 
 the beginning and ending of the making form convenient arti- 
 ficial or conventional boundaries to the section of the chain to 
 which we limit our contemplation. We must limit the scope 
 of our contemplation, because of the limitation of our powers, 
 which cannot grasp an indefinite length of chain ; and boun- 
 daries must be placed somewhere; and the boundaries fixed by 
 the beginning and ending of the making of a thing are apt for 
 our purpose. In contemplating causes, no less than in every 
 other operation of mind and body, we have a purpose in view, 
 and it is their indifference to purpose, and their ignoring of it, 
 that render the speculations of the philosophers described in 
 the first Chapter so curiously detached, irrelevant, and point- 
 less. Our purpose in investigating how a thing is made, or 
 comes to be, is to make it or prevent its being made, to cause 
 it or help it to be, or to prevent or hinder it being ; or in any 
 case to get some advantage out of our knowledge, even if it is 
 only the advantage of satisfaction in knowing more than we did 
 before. The only causes we need take into consideration are 
 those that answer our purpose, whatever that may be : to con- 
 sider more would only lead to confusion and embarrassment. 
 That is why, in grouping together as cooperating causes the 
 actions whereby a thing is made, or comes to be, we fix an 
 arbitrary limit beyond which we do not at the moment go. We 
 stop short at that stage, not because we imagine that the causes 
 began at that stage, but because it is among the causes subse- 
 quent to that stage that we expect to find those that we can 
 initiate, facilitate, hinder, or destroy. For the purpose in view, 
 the group is a natural group, and the limits are convenient 
 limits, and none the less so because for some other purpose we 
 may find it desirable to extend or to contract them. 
 
 SUBSIDIARY PROBLEMS. 9^ 
 
 Simultaneous Cooperation of Unlike Causes, 
 
 Unlike as well as like causes may cooperate simultaneously 
 or contemporaneously to produce an effect which, but for their 
 simultaneous or contemporaneous cooperation, would not have 
 been produced. Plants will not thrive except under the com- 
 bined action of light, warmth, and moisture. Without light 
 they will grow, but they will not thrive. Without some degree 
 of warmth, varying with the nature and habits of the plant, it 
 will not thrive, or even live ; neither will it thrive if desicca- 
 tion is carried beyond a certain point, or live if it is 
 carried beyond a certain further point. Iron rusts under 
 the simultaneous cooperation of moisture and of oxygen. In 
 dry air it will not rust, though constantly in contact with 
 oxygen. Immersed in water free from dissolved oxygen it will 
 not rust, although it is kept constantly wet. It requires the 
 simultaneous operation of the two causes to produce the effect. 
 A man who refuses to do a thing under threat of punishment 
 for non-performance, and refuses to do it for reward, may yet 
 be induced to do it by combining the threat of punishment 
 with the promise of reward. When a glass tube is held 
 horizontally in a flame until it softens, it will bend ; and the 
 bending is the effect of the cooperating action of heat and 
 gravity acting simultaneously. The running of a motor car, 
 the action of an engine, are the effects of numbers of causes 
 acting contemporaneously. 
 
 Indifferent Cooperation of Unlike Causes. 
 
 Finally, unlike causes may cooperate to produce an effect 
 when it is immaterial in what order the causes act, or whether 
 they act simuftaneously or in succession. A business firm may 
 be ruined by the cooperation of the defalcation of a clerk and 
 the failure, either at the same time, or before, or after, of a 
 debtor for a large amount. A man's death may be due to the 
 cooperation of several diseases, which would have effectually 
 killed him in whatever order they attacked him, together or 
 
 ; 
 
92 
 
 ON CAUSATION, 
 
 ! ii; 
 
 ^1' 
 
 successively. Rain and frost combine to produce the fall of a 
 mass of earth from a cliff, and in what order they act upon the 
 cliff is immaterial. 
 
 V. The Law of Universal Causation. 
 
 We are now done with the first of Dr. Fowler's propositions^ 
 and may consider the second, that every event has a cause. 
 This is what is known as the Law of Universal Causation, and 
 not only do logicians commonly confuse it, as Dr. Fowler points 
 out, with the definition of cause, and with the Uniformity of 
 Nature, but also it comprehends within itself four distinct 
 problems which are usually confused together. They are as 
 follows : — Does everyone believe that every event has a cause ? 
 If so, what is the warrant for the belief ? Is it true ? and 
 How do we come by it ? 
 
 In the first place, what is meant by an event ? I think we 
 may say without fear of objection that an event is that which 
 happens, and inevitably implies a change ; and as we have seen, 
 the idea of change is necessarily bound up in the idea of effect. 
 But changes are not the only effects. The prevention of change 
 equally demands a cause for its existence; and, with some 
 straining of the sense of words, unchanges may be included in 
 events. Taking this to be the meaning of event, then it is 
 evident that events are synonymous with effects ; or, if un- 
 changes be excluded from the denotation of events, then event 
 is synonymous with one of the two classes of effect. The first 
 question then becomes Does everyone believe that every effect 
 has a cause ? or Does everyone believe that a particular kind 
 of effect has a cause ? It seems to me that these questions 
 must necessarily be answered in the affirmative. Effect implies 
 cause, as husband implies wife, or any other relative implies its 
 correlative. They are of course separable in thought, as, indeed, 
 they are separable in fact, but, being correlative, their constant 
 association in fact cannot be denied. 
 
 Moreover, I think there is abundant evidence that not only 
 human beings, but many of the lower animals also, assume 
 causation for every change which is a change to them — which 
 
 ■ i 
 
 subsidiary problems. 
 
 93 
 
 is appreciated by them as change. Horses shy, dogs bark, birds 
 and animals of various kinds rush away, when events occur to 
 which they are unaccustomed, that is to say, which are out of 
 their ordinary routine, and to them imply change. And I think 
 we may safely assume that when horses shy and dogs bark at 
 such things they do so because they apprehend danger, which 
 is as much as to say that they have causation in their minds. 
 They apprehend the causation of harm to themselves. In the 
 same circumstances all timid animals either bolt, or conceal 
 themselves, or behave otherwise in a way that indicates that 
 they apprehend danger. .^In all such cases the change is viewed ^_„ 
 as the effect of some cause, and the cause of that effect may 
 produce other effects, and effects detrimental to the witness. 
 Of all the changes in surroundings that excite in both animals 
 and man the danger reaction, none is more potent than an un- 
 expected noise ; and no one apprehends danger from noise. 
 The apprehension is that, as there is a noise, there must 
 be an agent to cause the noise, and that what has caused 
 this effect may cause other effects. I think therefore that the 
 evidence is that every man does believe that every event has a 
 
 cause. 
 
 This opinion is corroborated by considering the way by 
 which we come into possession of it. I do not say that it 
 is the only way, but I do not think it can be disputed that 
 the chief source of this belief is as follows : — Man, and all his 
 ancestors throughout an immeasurable past, have lived by 
 action ; and every act of theirs has been an instance of ^^ 
 causation. It has been an action on something, and has 
 produced or prevented a change in the thing acted on. It 
 has been a cause, and has produced an effect. Hence the 
 notion of causation is in every individual of very early origin, 
 and with respect to his own action is inescapable and per- 
 petual. Contemporaneous with this enormous body of positive 
 experience, is the negative experience, equally inescapable, 
 and equally perpetual, that we cannot produce or prevent 
 change in anything without acting on that thing, either 
 directly or indirectly. Hence experience, from the dawn of w 
 consciousness to its last oblivion, perpetually enforces upon 
 
 ! 
 
 ' it^ 
 
 'I 
 
94 
 
 ON CAUSATION. 
 
 SUBSIDIARY PROBLEMS. 
 
 95 
 
 I 
 
 ! 
 
 us the conviction that change or prevention of change cannot 
 occur without action of or on the thing changed; in other 
 words, that every event has a cause. I think, therefore, that 
 the evidence warrants us in saying that everyone who is 
 capable of forming the notion of causation does beheve that 
 every event has a cause, and that he derives this behef from 
 experience. It may be well to point out that though I hold 
 the empirical origin of this belief, I do not found it upon the 
 supposition that the will is the cause of bodily movements. 
 Whether this is or is not a case of causation, it does not enter 
 into the demonstration. 
 
 The next question is, Granted that we do entertain this 
 belief, what is our warrant for it ? The warrant has already 
 been indicated. Jt is in experience. It is experience repeated 
 with incalculable frequency without a single contrary instance. 
 When I say without a single contrary instance, I do not mean 
 that in every case of change or prevention of change we are 
 able to assign a particular cause, or identify the cause ; that 
 of course would be directly contrary to experience. J mean 
 that in no case of change or prevention of change that has 
 ever occurred in experience are we able to exclude a cause, 
 or to be certain that no cause has acted. As I have said 
 . elsewhere, this is the conclusive test of truth for us— that 
 conduct founded upon a supposition never brings us up against 
 experience that contradicts the supposition. This is the 
 highest warrant we can have. Granted that the experience 
 is obtainable, granted that actions on the supposition are 
 incalculably numerous and diverse, then the fact that expe- 
 rience has never shown the supposition to be false, not merely 
 warrants us in believing that it is true, but compels us to 
 believe it is true. The belief is inescapable; and however 
 strongly we may in words deny it, the first time we act we 
 shall prove our belief in it by acting upon it. 
 
 The third of the four questions put at the beginning of this 
 section was Is it true ? Apart from our belief in it, is it true 
 that every event has a cause ? After the foregoing discussion, 
 this question ceases to have any meaning. If we have in 
 support of a supposition, and based upon it, incalculably 
 
 v 
 
 numerous experiences, not one of which has ever contra- 
 dicted the supposition, then for us that supposition is true. 
 It is certain. We are precluded from doubting it. We may 
 put together the words expressing a doubt, but those words 
 have no answering relation in our minds. That every event 
 has a cause is true in the sense that we cannot doubt it. 
 Whether it is noumenally true we cannot know, and it would 
 not matter if we did. It is true for us. It is true as far 
 as we are concerned. To ask whether it is really true is to 
 ask whether there is a higher degree of certainty than certainty 
 itself — whether that which is true for us may not be false in 
 some sense which we cannot clearly conceive, and with which 
 we are not concerned. The importance of knowledge is its 
 influence upon conduct; and in the influence they respectively 
 exert upon conduct there is no appreciable difference between 
 that which is universally true to all men, at all times, in all 
 places, and that which is noumenally true. 
 
 VI. The Uniformity of Nature. 
 
 The Axiom of Causation, 
 
 We are now arrived at the third of those propositions which 
 Dr. Fowler justly says few writers have not more or less 
 confounded, that the same cause is always attended with the 
 same effect. Dr. Fowler calls this the Law of the Uniformity 
 of Nature, and the title may as well be retained, though other 
 writers use it in other senses. In this case again there are 
 four different problems comprised in the one proposition; that 
 is to say, Do men universally believe that the same cause is 
 always attended by the same effect ? If so, How do they 
 come to believe it ? Is it true ? and What is their warrant for 
 believing it ? 
 
 Does every man believe * that the same cause is always 
 attended by the same effect ' ? This is the way in which 
 the problem is stated by Dr. Fowler, but Mill puts it 
 differently, and few writers seem to appreciate the difference. 
 Mill puts it that every consequent has an invariable ante- 
 
96 
 
 ON CAUSATION. 
 
 cedent ; by which he probably means that the same effect is 
 always due to the same cause; which is the converse of 
 Dr. Fowler's problem ; and as we have seen, Mill says this 
 although he has a whole Chapter on the Plurality of Causes, 
 by which he means that the same effect may be due to very 
 different causes. 
 
 It is clear that the answers to both of these questions must 
 depend upon the definitions that we adopt of cause and effect, 
 and will be very different if we adopt one definition from 
 what they will be if we adopt another ; but most of all they 
 will be influenced by our definition of the word ' same,' which 
 most writers on this subject, I think I may say all, interpret 
 so that it includes ' different.* It is perhaps this uncertainty 
 about the meaning of the chief terms employed that is respon- 
 sible for the differences of different writers on the subject. 
 Some assert that Nature is uniform ; some deny that Nature 
 is uniform ; some neither assert nor deny it ; some, like Mill, 
 both assert and deny it; and few of them mean by it the 
 same thing. In this chaos I shall follow Dr. Fowler, who 
 does at any rate say clearly what he means in this, as in most 
 
 things. 
 
 His reading of the Law of the Uniformity of Nature is 
 that the same cause is always attended by the same effect. 
 Is this true? As I have already said, it depends on what 
 we mean by the chief terms employed. If a cause means 
 the invariable antecedent of an effect, and if an invariable 
 antecedent means an antecedent that is the same in every 
 case, then whether or no the same effect always is attended 
 by the same cause, it does not follow that the same cause 
 is always attended by the same effect, and Mill's Plurality 
 of Causes forbids us to suppose that it does. In Mill's^ sense 
 of cause, therefore. Nature is certainly not uniform in Dr. 
 Fowler's sense. Whether it is uniform in Mill's sense we 
 cannot tell, for Mill muddles up the Uniformity of Nature 
 with the Law of Universal Causation. To Mr. Welton, 
 cause and effect are the same thing, and in this meaning of the 
 word ' cause' of course Nature is Uniform, for the same cause 
 must always be attended by itself, which is the same effect ; 
 
 SUBSIDIARY PROBLEMS. 
 
 and the same effect must always be att^nri^ri u .u 
 cause~by itself Professor T^^rl p ^^^^""^^^ ^y the same 
 
 of both c'ause and et but ve^^^^^^ ''"" ^'^ ^^^^^-- 
 of perceptions,' ^a routt of /xped^^^ r^- 
 
 impressions' appear, when takfn'w h Sei^^^^^^^^ 
 what other wnters mean by the Unifor^ of n^^^^^ 
 however, there s no cause anH nr^ ^«- . / ^^ature. If, 
 be no Uniformity of Naturf in Dr F ° '°"'"'' '''''' ^^" 
 Bertrand Russell^s state, "t of cauS .nT'^- "I^" 
 assertion that there is a rr.ncf . causality includes the 
 
 of the universe a one .nstam and '"°" ''*"^^" ^^^ ^'^'^ 
 at that instant. The constanev of th fT- '''' "' ^'^^"^^ 
 to imply that the nature o?he unil J ''°"."°"''' '''"" 
 Mr. Russell denies that th. u "" f. '^ ""'^^^ ' ^ut as 
 
 or only that of oth rs I So iot U "T'''^ ^"'^^'^^^ '^'^ °- 
 of a bygone ^EeTLlltZZTb^T'''''''' '"* ^ '^'^ 
 Nature is uniform in Dr'ToS's ^sen^ TlllS T 
 McTaggart can conclude after an PvhV * 1 ^* ^'■* 
 that it is impossible to nr. exhaustive discussion is 
 
 not hold unlvers lly Here I 31? ""..*'^^' 't' '^^ d°- 
 discuss the matter In the ITsis oT'^y ^^ LSnf '"^' ^"^ 
 
 s.onal definition, a cause is an actton Do'es th7s. "' '""■ 
 always produce the same effect ? Take t^e blow ofTh ' " 
 for instance : does the himv r.( u °' ^ hammer 
 
 effect whether it falls on rh?/ f'"T P'"°'^"^^ '^'^ ^^^e 
 or a man's fil^ or a baJfof T ' °' '''' ''^^ 
 ClearlyJnthiss?ns;ofthetrd W 'th°: ' ^'"' °^ ^^^'" ^ 
 always produce the same Xt and N.^'"''''°''"°' 
 But this definition of cause w,?' ^"I^.^^ "■•« '^ not uniform. 
 
 sequently elaborated into thrthT'"°"'' °"'^- '' ^^^^ ^"b" 
 thing ; and the nnr^til I' ^ ^ ^^"'^ '^ ^" action upon a 
 
 the si^e thing aC IT '^r'"" '''''' *^^ ''^' -^'O" "n 
 our hammer LTsS^ltri''?'^^^^^ Again let us take- 
 is a splash. NowTet the i °"!^ ^ r'/ ^^t«^- The effect 
 it again. The same ef?ectTn„r.''' ^^""'^"'^ '^'"^^*"ke 
 
 that the thing on wS? tL elus't?,^^^ It may be objected 
 
 tne cause acts is no longer the same 
 
 7 
 
 
98 
 
 ON CAUSATION. 
 
 thing, but it is quite arguable that it is the same thing. It is 
 certain, however, that it is not for the purpose of the argument 
 the same thing. Then in what respect does it differ ? Liquidity 
 and sohdityare, for the purpose of the argument, passive states 
 of the thing acted on by the cause, and according to the dehni- 
 tion already given, a passive state of the thing acted on by the 
 cause is a condition. It is evident, therefore, that the question 
 we are discussing, Does the same cause always produce the 
 same effect ? must be answered in the negative unless we amend 
 it by inserting a reference to the conditions ; and the question 
 ought to be put in the form Does the same cause in the same 
 conditions always produce the same effect? But this is 
 instance of the fallacy erroneously called the fallacy of many 
 questions, which should be called, as it is called in my New 
 Logic, the fallacy of the previous question. It implies that 
 a previous question, which has not been answered, has been 
 answered. It implies that the same action can take place for 
 a second time upon the same thing in the same conditions ; 
 and this is not only impossible, but is acknowledged to be im- 
 possible by many of'those who insist that the same cause always, 
 or as they say invariably, produces the same effect. 
 
 UavTu pH. ^■V11 existence,' says Mr. Welton for instance, 'is 
 continuous and uninterrupted transition,' and ' uniformity itself 
 is not to be taken to mean resemblance. It is in identity alone, 
 not in mere resemblance, that we can find a firm basis of infer- 
 ence.' But if all existence is continuous and uninterrupted 
 transition, or change, it is clear that a state of things once 
 passed can never in all respects be reproduced, unless time 
 should flow backwards, and of this we have no experience ; and 
 it is a commonplace that the same state of things never is repro- 
 duced. To get the same effect, the same cause must act on 
 the same thing in the same conditions ; and the cause is never 
 the same, the thing is never the same, and the conditions are 
 never the same. Therefore cadit qiicestio. In this sense, there 
 is certainly no such thing as Uniformity in Nature. 
 
 Yet the aphorism that the same cause invariably produces the 
 same effect, clumsily though it is asserted, and untrue though 
 it is, is the adumbration of a truth, and of a most valuable 
 
 SUBSIDIARY PROBLEMS. 
 
 truth. It is not true in any sense that the same cause invariably 
 produces the same effect; but if we recognise what logicians a I 
 gropmg after, and put it into precise and accurate lanTuai we 
 can assert a very important truth, upon which all our methods 
 but three of ascertaming causes are founded, a truth JS 
 which but few causes would ever be discovered. It is thi that 
 Like acUons on Uke things in like conditrons produce like eZt^ and 
 The more nearly alike the actions, the things acted on She con 
 d^t^onsthe n^ore closely alike mil the effect! te. We m"y Z Ze 
 same thought more concisely in the following aphorTsm -L t 
 causes tn like conditions produce like effects ^ "^"""^ • ^'^^^ 
 
 I do not think this aphorism needs proof. I doubt whether 
 t IS susceptible of proof. It seems to me to be an ax om As 
 oon as Its meanmg is grasped, it claims and secures o^se^t 
 Its con radictory, if not actually inconceivable scertaTnlv 
 incredible. Whether its truth is manifest . ^no^/LTs based 
 upon experience I do not care to speculate^ The universal 
 experience of mankind goes to show that, whether of emS 
 origin or not, it is empirically true ; and if we like to cl t an 
 instance, or an example, or a proof, of the Uniformity of Naure 
 I don t know that any harm will be done-or any .ood We 
 may, if we please, call it a proof of the Uniformity ofliatuTe 
 
 frequently employed kthf ' r f '"^'"'^ " P'^'^^P^ ""o^t 
 
 numerous, and everv one nff hi ^^''^ ff'^' t^e derivatives are 
 , ana every one of them is of frequent application. It 
 
 *ii 
 
 'Ml 
 
SUBSIDIARY PROBLEMS. 
 
 lOO 
 
 ON CAUSATION. 
 
 V 
 
 would be tedious to cite them all, but the following are samples^ 
 and we may, if we please, call each of them an instance or a. 
 statement of the Uniformity of Nature. 
 
 Like causes in like conditions produce like effects. 
 Like causes in unlike conditions produce unlike effects. 
 Unlike causes in like conditions produce unlike effects. 
 Like effects in like conditions are due to like causes. 
 Unlike effects in like conditions are due to unlike causes. 
 If like causes produce like effects the conditions are ahke.^ 
 If like causes produce unlike effects the conditions are unlike. 
 And so on. 
 
 Summary, 
 
 There is no such thing as Plurality of Causes in Mill's sense. 
 What he meant was that in different cases different causes 
 produce different effects that have some element in common, 
 and this common element he called the effect, and said that it 
 might have many causes. His error was in generalising the 
 effects without generalising the causes. 
 
 But every effect is due to a series of causes stretching back 
 
 into infinity. . 
 
 And this series is not single, but every effect requires both 
 a cause and conditions, and the conditions are themselves, 
 the results of causes; every effect is therefore due to an in- 
 definitely large number of series of causes converging on the 
 
 effect. 
 
 The cause of a condition is an indirect cause. 
 
 The cause of a cause is a direct, but more or less remote 
 
 cause. 
 
 The cause of an effect is that cause in which for a certain 
 
 purpose we are most interested. 
 
 To produce an effect, causes may cooperate in any of the 
 
 following ways. 
 
 Like causes may cooperate in succession, simultaneously, or 
 
 indifferently. 
 
 Unlike causes may cooperate in succession, and then must 
 preserve a certain order ; or simultaneously ; or indifferently. 
 
 lOI 
 
 The Law of Universal Causation has, in the books, several 
 incompatible meanings. It appears to be indisputable that we 
 believe that every event has a cause, and that this belief is shared 
 with us by many of the lower animals. This belief is founded 
 upon the constancy of our experience, and is true, or at any 
 rate is inescapable. 
 
 The Law of the Uniformity of Nature, as stated in the books, 
 is nonsense. Neither the same cause nor the sam.e effect is ever 
 repeated. The true Axiom of Causation is that Like causes in 
 like conditions produce like effects, and the more closely alike 
 the causes and the conditions, the more closely alike will be the 
 effects. On this axiom almost all our reasonings with respect 
 to causation are founded. 
 
 ii 
 
:r 
 
 CHAPTER VI. 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 When we have discovered an action upon the thing changed 
 or maintained unchanged, and have determined that the action 
 precedes the change or accompanies the unchange, we have 
 still not ascertained the cause ; we have only cleared the ground 
 m preparation for doing so. The cause is not ascertained until 
 we have established a necessary connection between the action 
 and the effect. This is what Mill's Methods of Experimental 
 Enquiry are designed to secure. Mill assumed, and the assump- 
 tion IS adopted from him by subsequent writers on the subject, 
 that the only way to discover causes is by experiment, and that 
 the only aim of experiment is to discover causes. Both assump- 
 tions are manifestly and transparently false, and are contradicted 
 by everyday experience. Some of the methods described by 
 Mill himself as experimental are not experimental, indeed he 
 admits that one of them is not ; and some of the instances he 
 gives of the determination of causes are instances of the deter- 
 mination not of the causes of things, but of their existence, or 
 their nature. 
 
 Logicians as a rule know nothing of natural science except 
 what they mug up for the purpose of finding instances where- 
 with to illustrate Mill's five methods, which he and they all call 
 four. They have therefore no means of knowing whether these 
 methods are used or not ; but they accept Mill's confident 
 assertion that in scientific investigations these methods and 
 no others are used. But though logicians know nothing of 
 natural science or of its methods except what they learn from 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 103 
 
 
 Mill, they cannot help, in common with the rest of the world, 
 assigning causes for the various events they meet with in their 
 daily lives ; nor can they help seeing that in thus ascertaining 
 causes, none of Mill's methods is ever used. They naturally 
 conclude that the methods of science and the methods of daily 
 life are utterly and totally different ; that when a man enters 
 his observatory or his laboratory he strips himself at the door 
 of all the methods he is accustomed to use, and employs an 
 entirely new set, a set of methods that are mysterious, recon- 
 dite, and complicated, that logicians regard with awe, and 
 do not venture to criticise. To these methods they give the 
 name of the Logic of Science, and they suppose that non- 
 scientific people have to be satisfied with a different and very 
 inferior Logic. This is all moonshine. 
 
 I assert, and the present chapter is designed to prove, that 
 the methods by which scientific men ascertain the causes of 
 those phenomena that are called scientific are precisely and 
 exactly the same as those by which the cook ascertains the 
 cause of the dinner being spoilt, and the child ascertains the 
 cause of its toy being broken. I assert, and will presently 
 prove, that the methods so clumsily and uncouthly described 
 by Mill are in fact never employed ; that they never could be 
 employed, for they are absurd, and when applied to actual cases 
 result in futility ; and I assert that when we seek to ascertain 
 the causes of things, and when we do ascertain them, we look 
 for an action upon the thing on which the effect is produced, 
 that is, on the thing changed or maintained unchanged ; and we 
 are guided in our search, as well as determined in our choice, 
 by one or more of the following considerations : — 
 
 I. Instant sequence of the effect on the action. 
 
 II. Subsumption of the case in hand under a general law. 
 
 III. Assimilation of the case in hand to a known case of 
 
 causation. 
 
 IV. Association of the action with the effect. 
 
 V. Concurrent and proportional variation of the action and 
 
 the effect. 
 
 VI. Common rarity of the action and the effect. . 
 
104 
 
 ON CAUSATION. 
 
 VII. Correspondence of a quality in the effect with a quality 
 in the agent. 
 
 VIII. Coincidence in space of an action or a condition with 
 the effect. 
 
 IX. Coincidence in time of the action with the effect. 
 
 The fifth of these methods, that of establishing an association 
 between the action and the effect, is further divisible into four 
 subordinate methods; so that altogether there are at least 
 twelve methods of ascertaining causation ; and these we may 
 now proceed to examine. 
 
 I. Instant Sequence. 
 
 When an action upon a thing is instantly followed by a change 
 in that thing, we are irresistibly driven to conclude that the 
 action is the cause of the change. 
 
 When a china cup falls to the ground and breaks at the 
 instant of its impact on the ground, we do not need to witness 
 
 * two or more instances in which the phenomenon occurs ' or 
 
 * two or more instances in which the phenomenon does not occur ' 
 before we can make up our minds that the action of the impact 
 was the cause of the breakage. We are driven to the conclusion 
 that this action was the cause of this effect ; and the main, if 
 not the only reason for our conclusion is the instant sequence 
 of the effect on the action. As already said, the writers 
 upon causation seem to think that causes never are attri- 
 buted, and that there is no need for the discovery of 
 causes, except in the laboratory or the observatory, or in 
 matters that are called, with more or less justice, scientific. 
 There was never a greater mistake. We are all of us 
 engaged daily, hourly, and almost momentarily, in the ascer- 
 tainment and attribution of causes; and it is much more 
 important to each of us in our lives to attribute causation cor- 
 rectly in matters that pertain to our immediate welfare, than 
 that we should ascertain the causes of the perturbation of a 
 planet, or of the mimicry of butterflies. Among the means by 
 w^hich we ascertain causes in our daily work, the instant 
 
 i >i 
 
 METHODS OF ASCERTAINING CAUSES. lo? 
 
 sequence of an effect upon an action is perhaps the most 
 trequent, and is by no means the least important. Nor is the 
 employment of this means confined to trivial matters of daily 
 occurrence. It is just as important and just as trustworthy in 
 the laboratory. When the chemist adds one clear liquid to 
 another, and a precipitate is instantly formed, he concludes at 
 once that the addition of the reagent was the cause of the 
 formation of the precipitate ; and he forms this conclusion 
 because of the instant sequence of the turbidity of the liquid 
 on his action in adding the reagent. 
 
 If we see a match applied to a thing, or a blow struck upon 
 It, and that thing instantly explodes, we attribute the explosion 
 to the application of the match or the striking of the blow • 
 and this we do without any need of two or more instances in 
 which the phenomenon occurs, and two or more instances in 
 which it does not occur. The instant sequence of the change 
 on the action assures us that they are effect and cause. Anyone 
 quite Ignorant of military evolutions who should see the troops 
 alter their formation immediately on hearing a bugle call 
 w-ould instantly regard the call as the cause of the movement! 
 If we pour oil into the bearings of an engine, and the engine 
 instantly increases its speed, or if we do the same to a foot- 
 lathe, and the lathe instantly runs easier, we have no hesitation 
 in attributing the change of speed, or the easier working, to 
 the action of lubrication. If a horse's head is turned towards 
 home, and he instantly improves his pace, we inevitably 
 connect the improvement causally with the change of direc- 
 tion If a bell rings or a whistle sounds in a factory, and the 
 workmen all instantly drop their tools, we cannot help regarding 
 the cessation from work as the effect of the sound; and similarly, 
 when the air is thick with the chirruping of birds, if a gun is 
 tired, instantlya dead silence ensues. We cannot help attributing 
 the sudden occurrence of the silence to the report of the gun 
 
 In some of these cases there may be other reasons which 
 corroborate our judgment, and in fact our judgment of 
 causation is seldom formed upon one method alone. Usually 
 two or more methods corroborate one another, and the third 
 method, the Method of Similarity, is seldom quite absent ; but • 
 
 il 
 
t II 
 
 1 
 4 
 
 A 
 % 
 
 % 
 
 » 
 
 I 06 
 
 ON CAUSATION. 
 
 in Others of the cases that have been instanced it is clear that 
 the conclusion was based upon the instant sequence of the 
 effect on the action, and upon no other method. One who 
 had never before seen a galvanometer, and knew nothing of 
 electric action, who should see the needle move the instant the 
 key was depressed, could scarcely avoid attributing the change 
 to the action. 
 
 Of course, the method is not infallible. In this imperfect 
 world few methods are infallible. In some cases it needs 
 corroboration or testing by some one or more of the other 
 methods. But for all that, it is a method; it is a method 
 that is constantly in use ; it is a method that by itself may 
 lead to a perfectly reliable conclusion ; and it is a method that 
 is not mentioned by any previous writer on the subject. Its 
 fallibility is shown by the familiar instance by which a child 
 is made to believe that he can cause the cover of a watch to 
 fly open by blowing on it ; but what is more important, the 
 same instance shows how very early in life the conclusion is 
 thrust upon us, that a change that follows instantly upon an 
 action is the effect of that action. 
 
 Mill and his commentators must each of them have used 
 this method thousands of times, but they none of them record 
 it, whether because it is difficult to put it into cumbrous and 
 obscure language, or because they do not consider it sufficiently 
 ' scientific,' I do not know. 
 
 l-i 
 
 II. SUBSUMPTION. 
 
 The second method of establishing a causal connection 
 between an action and an effect is by subsuming the instance 
 in hand under a general law. If this can be done, causal 
 connection is assured, and neither Mill's Canons nor any other 
 device is required to assure us of the necessary connection 
 between the action and the effect. 
 
 Whether the tides were associated with the moon before the 
 discovery of gravitation I do not know ; but as soon as gravi- 
 tation was discovered, and was applied to the action of the 
 moon upon the seas, it must have become apparent at once 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 107 
 
 that the moon's attraction must be the cause of tidal changes 
 in the level of the seas; and if tides had never before been 
 observed they would now be looked for. The action of the 
 moon on the sea, and the sequent change in the level of the sea, 
 are subsumed under the general causal law of gravitation, and 
 this subsumption gives us the assurance that the action is the 
 cause of the change. 
 
 When our waterpipes burst in winter, we find the cause 
 at once by subsuming the case under the general law that 
 water in freezing expands with immeasurable force; and by 
 this subsumption the action of the frost and the bursting of 
 the pipes are connected. When the cook goes to the cupboard 
 for a pot of jam, and finds it is not there, she says at once 
 ' Someone must have taken it.' She subsumes this instance 
 under the general law that inanimate things do not move from 
 their places without external agency. When the price of fish 
 rises, and we hear of gales in the North Sea, we assume a 
 causal connection between the action and the change, and we 
 do so on the strength of the general law that, other things 
 remaining the same, restriction of supply raises prices ; and 
 we know that gales in the North Sea do restrict the supply 
 of fish to this country. If the river overflows its banks, we 
 assume, unless it is a tidal river, that there has been much 
 rain in its catchment basin, and we make this assumption on 
 the strength of the general law that caeteris non mutandis, the 
 level of a river depends on the rainfall in the catchment area. 
 If we find an object of gold or silver that shows signs of having 
 been melted, we assume at once that it has been subjected to 
 great heat, for it is a general law that great heat is necessary 
 to the melting of gold and silver. If we find iron rusty, we 
 assume that it must have been damp, for it is a general law 
 that dry iron does not rust. When we are seeking the cause 
 of a rare disease, and we find that it affects the members of 
 several families in conformity with the laws of Mendel, we 
 have no hesitation in concluding that the cause is hereditary 
 transmission. 
 
 Neither in these cases do we look for two or more instances 
 of the phenomenon, and ask if they have only one circumstance 
 
V 
 
 .1' 
 
 f t 
 
 
 Sh 
 
 
 io8 
 
 ON CAUSATION. 
 
 
 in common, nor do we look for two or more instances in which 
 the phenomenon does not occur, and ask if they have nothing 
 in common but the absence of the phenomenon. What we do 
 is to subsume the case in hand as an instance under a general 
 law applicable to such instances ; and if the subsumption is 
 good, then the causal connection is made out to our satisfaction. 
 This method, which is distinct enough in cases like the tides 
 and the Mendelian inheritance of disease, is in other cases less 
 pronounced, and graduates and merges into the next. 
 
 III. Similarity. 
 
 Unquestionably the most usual and freqpnent ground for 
 assuming a causal relation which is not immediately apparent 
 is the similarity of the case in hand to other cases in which the 
 causation has been ascertained. As it is the most frequent, so 
 it is the most direct application of the fundamental Axiom of 
 Causation, that Like causes in like conditions produce like effects, 
 from which we obtain, by a logical process that is unknown to 
 logicians, the immediate inference that Like effects in like con- 
 ditions are due to like causes. It is by the application of this 
 method not only that causation is most often established, but 
 also that some of the most important discoveries of causes in 
 the various sciences have been made. It is in perpetual use, 
 both in the most recondite problems of science, and in the 
 commonest affairs of daily life. 
 
 It is asserted in nearly every book on Logic that the planet 
 Neptune was discovered by Mill's Method of Residues. The 
 planet Neptune was not discovered by the Method of Residues. 
 The very descriptions of the discovery that are given to show 
 that it was discovered by the Method of Residues show that it 
 was not discovered by the Method of Residues, and the same is 
 true of every other instance in which the books assert that 
 a cause has been discovered by this method. No cause of 
 anything has ever yet been discovered by the Method of 
 Residues, and it is extremely unlikely that any cause of any- 
 thing ever will be discovered by it. What was discovered by 
 the Method of Residues was that there were certain move- 
 
 M 
 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 109 
 
 ments of the planet Uranus that were not accounted for by 
 known causes. The Method of Residues did not discover the 
 cause, nor point to the cause. All it discovered, and all it 
 pointed to, was that there was something for which an addi- 
 tional cause was required. The additional cause was discovered 
 by the Method of Similarity. It was found by applying the 
 Axiom Like effects in like conditions are due to like causes. After 
 all the perturbations of Uranus that are due to the attraction 
 of known planets had been reckoned, it was found that there 
 was a residue of perturbation unaccounted for; and this led 
 astronomers to guess that there must be some other cause of 
 perturbation, yet unknown, and to look for it. The astronomer 
 said * This residual effect must be due to some extra cause that 
 I have not reckoned on. But though it is a new effect, it is 
 not a new kind of effect. I am familiar with perturbations of 
 planets, and I know how they are produced. They are produced 
 by the attraction of other planets. Now, Like effects in like 
 conditions are produced by like causes ; therefore this perturbation 
 must be due to the attraction of some undiscovered planet, 
 and I must proceed to discover it. In order to produce this 
 effect, the causal agent must have been in a certain place at a 
 certain time.' Then he investigates, and finds that at that 
 time Neptune was in that place. 
 
 Precisely the same method is employed by the cook when 
 she finds herself short of a pot of jam. This also is a residual 
 phenomenon. After accounting by known causes for the 
 absence of most of her jam, she finds there is a residue of loss 
 that cannot be so accounted for. This is all she can learn from 
 the Method of Residues. She learns from it that there is 
 something for which a cause is required. She then sets to work 
 to discover the cause. She says ' This loss must be produced 
 by some cause that I have not reckoned on ; but though it is a 
 new effect, it is not a new kind of effect. I am familiar with 
 the abstraction of pots of jam from my cupboard, and I know 
 how it is produced. It is produced by the action of human 
 hands. Now, Like effects in like conditions arc produced by like 
 causes ; therefore the abstraction of this pot must be due to the 
 hands of some undiscovered person. In order to produce this. 
 
¥'i 
 
 
 
 Hi 
 
 I 10 
 
 ON CAUSATION. 
 
 effect, the causal agent must have been in a certain place at a 
 certain time.' Then she investigates, and finds that at that 
 time the page-boy was in that place. 
 
 It is the same with every other application of the Method of 
 Residues. What is found by it is not the cause of anything, 
 but something unaccounted for, something requiring explana- 
 tion, something for which a cause must be found ; but in finding 
 the cause the Method of Residues is never employed, and 
 would be useless if it were employed. The cause is found by 
 one of the methods here described, and very often by the 
 Method of Similarity. 
 
 When physicians desired to know the cause of yellow fever, 
 did they proceed by the Method of Agreement, or the xMethod 
 of Difference, or the Joint Method of Agreement and Difference, 
 or the Method of Concomitant Variation, or the Method of 
 Residues? They did not. They were not so foolish. The 
 way they went to work was to assume that the cause of this 
 disease is like the cause of a similar disease occurring in similar 
 conditions. There is no disease exactly like yellow fever: 
 such a disease would be yellow fever itself; but there is a 
 disease, ague, which is like enough to yellow fever for the 
 purpose of the argument ; and the cause of ague is known. 
 Ague is caused by the injection, by the bite of a mosquito, of a 
 parasite into the blood ; therefore, it was argued, on the ground 
 of the Axiom of Causation, that yellow fever also is caused by 
 the bite of a mosquito; and suitable investigations being made, 
 the conclusion was verified in this case and in that. But it 
 was not verified in every case, and it cannot be verified in every 
 case. In the cases that now come under care, we do not and 
 cannot satisfy ourselves by observation or experiment that they 
 have been caused by the bites of mosquitoes ; but for all that 
 we do not doubt for a moment that they have been so caused. 
 What, then, gives us our assurance ? The same variant of the 
 Axiom of Causation, that Like effects in like conditions are due to 
 like causes. 
 
 When a chemist wishes to determine whether lead is present 
 in certain water, he applies certain reagents ; and if he obtains 
 certam results, he concludes at once that lead is present ; and 
 
 f " 
 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 I I I 
 
 so sure is he, that he is prepared to go into a court of law and 
 swear to it. By what method has he ascertained that the 
 cause of the reactions that he obtained was the action of lead 
 in the water? By the same method that leads the cook to 
 conclude that the disappearance of her jam was due to the 
 action of the page. The chemist knows that on every previous 
 occasion on which he or anyone else has ever tried it, lead has 
 had this effect, and nothing else has ; and he assumes at once 
 that since the effect and the conditions are similar, the cause is 
 similar. 
 
 When the photographer finds that directly he pours his 
 developer on the plate, the image leashes up, he knows that the 
 plate has been grossly over-exposed ; and he discovers the 
 cause of this effect by the Method of Similarity. The effect is 
 like the effect that has in like conditions been produced by 
 a certain cause; therefore, he concludes, the cause in this 
 instance is like the cause in that. Is his plate fogged ? Then 
 he concludes that diffused light has fallen on it, and his reason 
 is the same. Is his result brilliant ? Then he determines that 
 on future occasions he will repeat the conditions as closely as 
 possible ; and is confident that the more closely he can get 
 them like the conditions in this case, the more closely similar 
 will be the result. 
 
 When the horticulturist finds his tomatoes suffering from 
 disease displaying certain symptoms, does he apply any of 
 Mill's Canons ? Not if he knows his business. He looks 
 round for similar diseases in similar plants, confident that if 
 Ije finds such a disease, and the cause of it is known, he may 
 assume a similar cause for the disease of his tomatoes. He 
 has not far to look. On his potatoes, plants belonging to the 
 same natural order as the tomato, he finds a very similar 
 disease; and he knows that this potato disease is due to a 
 fungus of a certain kind. He concludes at once that the 
 disease of his tomatoes is due to a fungus, and to a similar 
 fungus ; and more, he concludes that whatever treatment 
 effectually cures the disease of his potatoes is likely to relieve 
 the disease of his tomatoes. He does not look for two or more 
 instances which have nothing in common but the occurrence 
 

 if 
 
 .■I 
 
 .1 
 I 
 
 f 1 
 
 |( 
 
 til 
 
 I 12 
 
 ON CAUSATION. 
 
 of the phenomenon, and two or more instances which have 
 nothing in common but the absence oi the phenomenon : he 
 looks for a single instance as like as possible ; and having found 
 an instance that is like enough for the purpose of the argument, 
 he looks no further, for he knows that Like effects in like con- 
 ditions are due to like causes, 
 
 A remarkable instance of the application of this method has 
 recently divided with the war itself the interest of this country. 
 Four women in four different parts of the country were found 
 drowned in baths under conditions that were closely similar; 
 and the similar conditions were not only closely similar, but 
 were numerous. In each case the woman was recently 
 married ; in each case she either possessed money or her life 
 had been recently insured ; in each case she had made a will in 
 favour of her husband ; in each case the husband reported the 
 death on his return from going out to buy food ; in each case 
 the woman had been said by the husband to have fits, though 
 she was not otherwise known to have them ; in each case 
 the funeral was hurried, and w^as carried out as cheaply as 
 possible. Such closely similar effects in such numerous closely' 
 similar conditions pointed conclusively to closely similar causes 
 and closely similar agents. When it was discovered that in all 
 the cases the husband was the same man, the similarity became 
 merged in identity. This one circumstance was antecedent in 
 every case, and was the only common antecedent ; and it was 
 impossible to doubt that he was the agent that had produced all 
 the effects. But the Method of Similarity, though by itself it was 
 sufficient, was not the only method employed in discovering 
 the agent. The sixth method also, the Method of Common 
 Rarity, was employed. It is, in fact, not usual for the discovery 
 of a cause or of an agent to be made by the employment of one 
 method only; and here we may give an anticipatory instance 
 of the Method of Common Rarity. Death in a bath is rare. 
 Death in a bath of a newly married woman, under all the 
 conditions enumerated, is extraordinarily rare. The rarity of 
 the effect pointed in each case to a cause equally rare ; the 
 common rarity of all the effects pointed not merely to rarity,, 
 but to actual uniqueness of the cause and of the agent. In all 
 
 11 fi 
 
 m 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 113 
 
 the cases there was but one common factor that alone could 
 possibly be the agent, and this was the husband ; who was 
 accordingly charged with murder, tried, convicted, and 
 executed. 
 
 Instances of the application of the Method of Similarity 
 might be multiplied indefinitely. It is the ordinary common 
 method of discovering those causes that are not forced upon 
 our attention by the Method of Instant Sequence ; it is used 
 by everyone many times every day, and is more frequently 
 employed in scientific investigations than any other method ; 
 but logicians, though in common with other people they are 
 constantly using it, have never described it, and never dis- 
 covered it. 
 
 IV. Association. 
 The mere association between an action upon a thing and a 
 following change or accompanying unchange in that thing 
 points to a causal connection between the action and the effect, 
 and is often taken to establish the causal connection. It does 
 not necessarily establish the connection, but in certain circum- 
 stances it may do so, and our task is to discover and state these 
 circumstances. 
 
 This is the method so clumsily expressed, and so erroneously 
 expressed, by the first three of Mill's Canons, which we may 
 now examine. The first thing that strikes us upon reading 
 them is the extraordinary cumbrousness, the elephantine pon- 
 derosity, of their expression. A statement is not necessarily 
 erroneous because it is badly expressed ; but cumbrous and 
 awkward expression is a sign of confusion of thought ; and 
 when we find such portentous circumlocution as these Canons 
 display, we may be quite sure that the writer is trying to 
 convey some thought that he has not thoroughly worked out ; 
 that it is certainly no more than an approximation to the 
 truth ; and that it is very likely to be erroneous. Elegance of 
 expression is no guarantee of accuracy, but it is an indication 
 of care ; and clumsiness of expression is an almost certain sign 
 of confusion and want of thoroughness in thought. 
 
 The first of the Canons runs : ' If two or more instances of 
 
 8 
 
K twa wi i y iwE sag-w 
 
 — ' 
 
 .« 
 
 »■ 
 
 
 114 
 
 ON CAUSATION. 
 
 the phenomenon under investigation have only one circum- 
 stance in common, the circumstance in which alone all the 
 instances agree [why not ' this circumstance ' ?] is the cause 
 (or the effect) of the phenomenon/ 
 
 Apply this to a concrete case, and let the * phenomenon 
 under investigation ' be green colour. Two or more instances 
 of green colour (a bucket, an armchair, and a pool ball) have 
 only one circumstance (that they are green) in common ; this 
 circumstance is the cause (or the effect) of the green colour. 
 
 So obvious is this booby-trap that some of Mill's followers 
 have noticed it, and have modified the Canon so that it reads 
 ' have only one other circumstance in common.' Let us see 
 how the amendment works out in practice, and let the ' phe- 
 nomenon ' still be green colour. 
 
 If two or more instances (a bucket, an armchair, and a pool 
 ball) of the phenomenon under investigation (green colour) 
 have only one other circumstance (that they are in the same 
 house) in common, this circumstance (being in the same house) 
 is the cause (or the effect) of the green colour. 
 
 Of course, according to my nomenclature, the green colour 
 of these objects, since it is neither a change nor an unchange, 
 is not an effect but a result ; but it is certainly a phenomenon, 
 and according to Mill's nomenclature it is an effect ; and out of 
 his own mouth must he be judged. If he had recognised that 
 an effect means a change or an unchange, and that a cause 
 means an action, and had expressed his Canon accordingly, it 
 would have at least been true, though even then it would not 
 have been much use. It would then have run as follows : — 
 
 If two or more instances of an effect are preceded or accom- 
 panied by only one mode of action on the thing changed or 
 unchanged, that mode of action is the cause of the effect in 
 each case. 
 
 This of course would be true, but when was there ever such 
 an effect? Events in this world are not thus isolated, and we 
 have no experience, and are never likely to have any experience, 
 of an effect that is preceded or accompanied by one action and 
 no more on the thing in which the effect is produced. 
 
 Mill's second Canon runs thus : — ' If an instance in which 
 
 jA 
 
 P 
 
 METHODS OF ASCERTAINIXG CAUSES. 
 
 the phenomenon under investigation occurs, and an instance 
 in which It does not occur, have every circumstance in common 
 save one, that one occurring only in the former ; the circum- 
 stance in which alone the two instances differ, is the effect or 
 the cause, or an indispensable part of the cause, of the oheno 
 menon.' ^ 
 
 Again let us clothe these dry bones in flesh and skin, and let 
 the phenomenon still be green colour. If an instance (a pool 
 ba 1) m which the phenomenon under investigation (green 
 colour) occurs, and an instance (another pool ball) in which it 
 does not occur, have every circumstance in common save one 
 (touching the cushion) that one occurring only in the former • 
 the circumstance (touching the cushion) in which alone the 
 two instances differ, is the cause, or the effect, or an indis- 
 pensable part of the cause of the phenomenon (the green 
 colour). ' ° 
 
 In terms of action and effect, this Canon would run as 
 follows :-' If an action and an effect in the thing acted on are 
 associated both in presence and in absence, everything else 
 being the same, the action is the cause of the effect.' This of 
 course is true, but in practice the Canon, even in this form, is 
 of no value, for everything else never is the same. In order to 
 give It any value the Canon should run :-' every other material 
 circumstance remaining the same.' In this form the Canon is 
 true and is valuable, but it is a very different Canon from 
 Mills. 
 
 Mill calls his third Canon the Joint Method of Agreement 
 and. Difference, and puts it thus:— 
 
 ' If two or more instances in which the phenomenon occurs 
 have only one circumstance in common, while two or more 
 instances in which it does not occur have nothing in common 
 save the absence of that circumstance ; the circumstance in 
 which alone the two sets of instances differ is the effect or the 
 cause, or an indispensable part of the cause, of the pheno- 
 menon. . ^ 
 
 In a concrete instance, If two or more instances (say a blade 
 of grass a garden seat, and a park gate) in which the pheno- 
 menon (green colour) occurs have only one circumstance (that 
 
 I' 
 
ii6 
 
 ON CAUSATION. 
 
 1^ 
 
 they are out of doors) in common, while two or more instances 
 (say a reel of cotton and a frying-pan) in which it does not 
 occur have nothing in common save the absence of this 
 circumstance (being out of doors) the circumstance (being out 
 of doors) in which alone the two sets of instances differ is the 
 cause, or the effect, or an indispensable part of the cause, of the 
 phenomenon. 
 
 The qualifications of this Canon are grotesque. When were 
 there ever two instances of any ' phenomenon ' that had only 
 one circumstance in common ? It is impossible to find such 
 instances, and impossible to imagine such instances. The 
 supposition is outrageous. If the * phenomenon ' is a material 
 thing, or a change in a material thing, the instances must have 
 at least the common circumstance that they are all subject to 
 the action of gravity. If the 'phenomenon ' is a mental state 
 or a mental change, the instances must have at least in common 
 the circum.stance that they are in some mind or other. And 
 how is it possible to find two other instances that have nothing 
 in common but the absence of the * phenomenon ' ? Instances 
 of what? Of the 'phenomenon'? No, for that is to be 
 absent. Of the * circumctance ', then ? No, for that also is 
 to be absent. And these instances of nothing are to have 
 nothing in common but the absence of the * circumstance ', yet 
 they are to have also in common the absence of the ' pheno- 
 menon ' ! Was there ever such a farrago oi nonsense ? And 
 yet this precious Canon was not only gravely stated by Mill, 
 but has been gravely accepted by every writer of his school 
 ever since, and in seventy years not one of them has discovered 
 its tomfoolery ; nor has even any one of his critics, and they are 
 numerous enough, discovered its tomfoolery. Had its author 
 been anyone else, I should have suspected him of perpetrating 
 a huge joke, and laying an elaborate trap for his worshippers ; 
 but Mill was as destitute of humour as Herbert Spencer him- 
 self, so that hypothesis will not stand. No. The only expla- 
 nation is that Mill, and everyone else who has accepted or 
 criticised the Canons, have had their minds so bemused and 
 bemuddled by the study of Traditional Logic, that they are no 
 longer capable of distinguishing sense from nonsense. 
 
 Vh'A 
 
 METHODS OF ASCERTAINING CAUSES. I17 
 
 As with the previous Canons, Ihave tried to make sense of 
 this by translating the terms ' circumstance ' and * pheno- 
 menon ' into action and effect, but no such amendment, and 
 no amendment of any kind, can make sense of it. Its inepti- 
 tude is hopeless and incurable, enormous and incredible ; and 
 no tinkering or patching can amend it. 
 
 Preposterous as these Canons are, both in sense and in 
 expression, they are nevertheless blind gropings after a meaning 
 that is both true and valuable ; that is to say, that there are 
 circumstances in which the association of an action on a thing 
 and an effect ifi that thing indicate a causal connection between 
 the action and the effect, and that these circumstances may 
 be formulated. We have already seen that this is true in one 
 set of cases— in those cases in which the effect is associated in 
 mstant sequence with the action— and have now to sho»w 
 what other cases there are. It must first be insisted that the 
 mere association of an action on a thing with an effect in that 
 thing does not necessarily imply causation. The sun may 
 shme on a house when it falls down ; or on a river when it 
 overflows ; the birds may be singing in the hearing of two 
 pugilists ; the train may be late when the rain is falling on it ; 
 the wind may be blowing on the corn when it is falling in 
 swathes; all these actions may be associated in time with 
 effects in the things acted on, and yet the association does not 
 justify us in concluding that the action is the cause of the effect. 
 Nor can we draw this conclusion from an association in space. 
 Grooming the horse is not the cause of its casting its shoe ; 
 painting the gate is not the cause of its being out of plumb : 
 putting the kettle on the fire is not the cause of the fire burning 
 up, or of the kettle being full ; crossing the swing bridge is not 
 the cause of its opening. 
 
 Yet there are cases in which we may properly argue from 
 association to causation, and it is important to distinguish the 
 cases m which we are warranted in so arguing from those in 
 which we are not. There are four such cases, that is to say— 
 Causal connection between an action on a thing and an 
 effect in that thing may safely be argued from their associa- 
 tion 
 
 i , 
 
I 1 
 
 "I 
 
 II ^» 
 
 Ji8 
 
 ON CAUSATION. 
 
 A. When other material action can be excluded ; 
 
 B. When the association is of proved constancy ; 
 
 C. When, though inconstant, the association is more frequent 
 
 than casual concurrence will account for ; 
 
 D. When, though itself inconstant, the associated effect has 
 
 constant peculiarities. 
 
 A. If a certain action on a thing is associated with a certain 
 effect in that thing, and all other material action can be 
 excluded, then that action is the cause of that effect. 
 
 This is indubitable. It needs no proof. It is axiomatic ; 
 and the method is unassailably valid whenever it can be 
 employed ; but the occasions on which it can be employed are 
 restricted. Of course, if it were necessary to exclude all other 
 action, the method could never be employed at all, since such 
 exclusion is impossible. In material things, for instance, it 
 would often be impossible to exclude the pressure of the air, 
 and always impossible to exclude the action of gravity. But 
 there are few cases in which causation needs to be investigated 
 and in which these actions are material. A greater difficulty is 
 to know what actions are material to the effect and what are 
 not ; and even if we do know this, it may be difficult to exclude 
 all the material actions but one; and often there may be a 
 material action at work of which we know nothing. If we 
 suspect an action of being the cause, and can isolate it, the 
 method is easy, and the result, positive or negative, is certain ; 
 but in many cases in which we have to depend on the method 
 of association the inquiry is a fishing one. There may be no 
 single action that can be plausibly suspected, and the number 
 of actions that may, for aught we know, be material, may be 
 indefinitely great. Take the case, for instance, of a disease. 
 It occurs among men and women whose course of life brings 
 upon them the action of innumerable agents, some of which we 
 know ; some of which, without knowing, we suspect ; and 
 many others of which we are altogether ignorant, and of whose 
 very existence we entertain no suspicion. Yet any of these 
 may, for aught we know, be material. In such a case it is in- 
 evitable that the method of association, employed loosely and 
 without rigour, as it always is at first, should lead us astray. 
 
 « 
 
 > I 
 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 119 
 
 In such cases we are apt to choose, pretty much at random, an 
 action or an agent that may or may not exist, and assign to 
 this action or agent, real or imaginary, a causal influence. We 
 assign the causation of disease, or of a disease, to the planets ; 
 to the air ; to some food, or ingredient in food, such as purin ; 
 to some drink, or ingredient in drink, such as port wine ; to 
 anything in the heavens above, or in the earth beneath, or in 
 the waters under the earth. These are mere random specula- 
 tions ; it is not until we submit our speculation to the test of 
 one of the twelve methods here described that any reasonable 
 assignment of cause begins; and the method that first 
 suggests itself is usually the method of association. The first 
 step towards accuracy is made when we establish an association 
 in time or space between the agent or action that we have 
 tentatively fixed upon and the effect or result whose cause we 
 are seeking. 
 
 It is not enough, however, to establish an association in 
 time or space between them, for, in such an effect as disease, 
 innumerable actions on the body of the patient are associated 
 with the disease. It is necessary to pick out one particular 
 action, and prove that it is associated with the disease in one 
 of the four ways that have been enumerated above ; and the 
 most obviously conclusive association is that now under con- 
 sideration, viz., association in isolation ; that is to say : — 
 
 If, in given conditions, other material things remaining the 
 same, the addition alone of an action is attended by an effect, 
 or the withdrawal alone of an action is attended by the dis- 
 appearance of an effect, that action is the cause of that effect in 
 those conditions. The obverse also is true : — 
 
 If, in certain conditions, other material things remaining the 
 same, the addition of an action is not attended by an effect, 
 or the withdrawal of an action is not attended by the dis- 
 appearance of an effect, that action is not the cause of that 
 effect in those conditions. Both these maxims are easily 
 derivable from the Axiom of Causation. 
 
 Unlike Mill's so-called Experimental Methods, these methods 
 are almost of necessity experimental. The isolated addition or 
 withdrawal of an action does not often take place unless it is 
 
 J I 
 
hi 
 
 120 
 
 ON CAUSATION. 
 
 i.'^i 
 
 artificially produced. If, however, the action can be isolated, 
 and added or withdrawn without disturbing other material 
 actions or conditions, then a single instance is all that is 
 necessary to establish causation, not only for that instance, 
 but generally for all cases that are similar in material respects. 
 
 Is the pressure of the air the cause of the maintenance of 
 the mercury in a Torricellian barometer ? If we place the 
 barometer in a chamber, and exhaust the air from that chamber, 
 we can determine the question with certainty, for by so doing 
 we withdraw the single action of the air-pressure, and leave all 
 other material actions and conditions unaltered. 
 
 What is the cause of the baby's crying ? Is a pin pricking 
 it ? The nurse undresses the baby and finds a pin in such a 
 position that it may perhaps have pricked the baby. She 
 removes the pin, and the crying ceases. Was the pricking of 
 the pin the cause of the crying? We cannot be sure. We 
 are not sure that there was any such action on the baby as we 
 supposed, and therefore cannot be sure that any such action 
 was withdrawn. Nor can we be sure that other material things 
 have remained the same. In undressing the baby some other 
 source of pain or discomfort may have been removed. 
 
 What is the cause of this cutting in my greenhouse wilting ? 
 Is it drought ? I water it, and after the lapse of an hour I can 
 discern no difference : the cause is not drought, therefore. Is 
 it the scorching of the sun ? I move it into the shade, and in 
 due time it recovers. There is little doubt the cause was 
 scorching ; but in moving it, I may have altered other condi- 
 tions. If, however, instead of moving it, I screen it from the 
 sun, and find that it recovers, I can have no doubt that scorching 
 was the cause. 
 
 A certain milk or water supply is suspected of being the 
 cause of an epidemic of disease. If, upon cutting off that 
 supply, the epidemic ceases to extend, the suspicion is con- 
 firmed. If the spread of the epidemic is unaffected, the 
 suspicion is removed. In this case the conditions are complex, 
 and it is difficult to be sure that all other material circumstances 
 remain the same. Even if the suspected supply is the cause of 
 the disease, the epidemic may still spread after the supply is 
 
 I ! 
 
 I . i 
 
 i; 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 121 
 
 cut off, for persons who were infected before the supply ceased 
 may not exhibit the disease until a week or a fortnight after- 
 wards. Again, suspicion of the supply may lead many people 
 not to use it, or to boil the milk or the water before using it, 
 and in such a case other material circumstances will not be 
 the same, and again the effect will be obscured. If, however, 
 the conditions of the test can be observed, and are observed, 
 then the test is infallible. 
 
 Is the fogging of the photographic plates due to leakage of 
 light into the camera? Expose the next plates in another 
 camera, and observe the result. If they are not fogged, the 
 fault is probably in the camera, but it is not certainly so unless 
 we can be sure that all the other operations were carried out 
 in the same conditions. If the plates are still fogged, the fault 
 is probably not in the camera, but this is not certain, for the 
 second camera also may not be light tight. The method 
 requires care and strictness in its application, but, properly 
 applied, it is thoroughly trustworthy. 
 
 Is the discontent in the regiment due to the incompetence or 
 lack of judgement in the colonel ? Remove the colonel, and 
 see if it subsides. In this case, again, there are sources of 
 fallacy. A regiment that has once got out of hand cannot be 
 restored to discipline in a day, or a week. The evil that men 
 <io lives after them ; and it may be that no ordinary man, and 
 no ordinary measures, will cure the regimental defect. Even 
 in so simple a matter as altering the pendulum of a clock we 
 may be deceived, unless we take precautions to observe that all 
 other things remain the same. It may be that the very day 
 we lengthen the pendulum a severe frost sets in and counteracts 
 our action by shortening it. In short, the sources of error in 
 the application of this method are numerous, and are often 
 difficult to guard against ; but none the less is the method 
 perfectly efficient if we can and do eliminate errors in its 
 application. 
 
 By these instances we may see that the method requires 
 great care in its application ; that it is often difficult, and often 
 even impossible to isolate the action, and to be sure that in 
 adding or withdrawing it, no other material action has been 
 
 I 
 
11 
 
 122 
 
 ON CAUSATION. 
 
 \ 
 
 M 
 
 MJ 
 
 added or withdrawn; nevertheless these instances also show 
 that when the method can be employed, and when it is employed 
 with care, it yields results which are perfectly trustworthy. 
 
 B. When the association of an action with an effect, though 
 not isolable, is yet of proved constancy, causal connection 
 between the action and the effect may be presumed. By proved 
 constancy is meant constancy without exception in cases that 
 are numerous and diverse. 
 
 Constant association between an action and an effect may 
 be association in presence, that is to say, that if one is present 
 the other also is present ; or it may be association in absence, 
 that is to say, that if one is absent the other also is absent. 
 In practice these amount to the same thing. 
 
 Constant association in presence may mean that whenever in 
 given conditions the action occurs, the effect occurs ; which is 
 the same thing as saying that whenever the effect is absent the 
 action is absent. In this case, the more numerous and diverse 
 the instances in which the association is observed, the more 
 surely we may presume that the action is a cause of the effect ; 
 but we have no reason to assume that it is the sole cause. 
 
 Or it may mean that whenever in given conditions the effect 
 is present, the action is present ; which is the same as saying 
 that whenever the action is absent the effect is absent. In this 
 case, the more numerous and diverse the instances, the more 
 surely we may presume that the action is the sole cause of the 
 effect. 
 
 The removal of a queen bee from the hive is always followed 
 by the rearing of a new queen by the bees ; and this associa- 
 tion has been so frequently observed without any exception, 
 that we may now confidently presume that the removal of the 
 queen is a cause of a new queen being reared. We may not 
 however, presume on the ground of this association, constant 
 though it is, that the removal of the queen is the sole cause of 
 a new queen being reared ; and in fact bees at a certain time 
 of year will always rear new queens, even if the old queen 
 remains. A severe frost when fruit trees are in flower is always 
 followed by failure of the crop, and the association is so constant 
 
 m 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 123 
 
 that we may conclusively presume that the frost is a cause 
 of the faiUre. We may not, however, presume from this mode 
 of constant association that frost is the only cause of failure of 
 the crop, and in fact it is well known that it may fail from 
 other causes. The warrant for the presumption, and the 
 justice of it, are so manifest that no further illustrations are 
 needed. 
 
 If the effect never occurs unless the action occurs, this mode 
 of constancy in association warrants us in concluding, and if 
 the cases are numerous and diverse compels us to conclude, not 
 merely that the action is a cause of the effect, but that it is the 
 sole cause. A watch never goes unless it is wound : we are 
 compelled to conclude that the winding is the sole cause of the 
 going. Eggs never hatch unless they are incubated: we are 
 compelled to conclude that incubation is the cause, and the 
 sole cause, of the hatching. This man is never quarrelsome 
 unless he is drunk: we are justified in concluding, and com- 
 pelled to conclude, that his drinking is the sole cause of his 
 quarrelsomeness. Certain flowers are never fertilised unless 
 they are visited by insects: we are justified in concluding, and 
 compelled to conclude, that the visits of insects are the sole 
 cause of fertilisation. Cancer of a certain kind is never found 
 except among chimney-sweeps ; chimney sweeping is the sole 
 cause of t^-a-t kind of cancer. Instances could be added in 
 indefinite numbers. It is important to appreciate that the 
 constancy of association is quite a sufficient warrant for con- 
 cluding causation, even though we may not know, and may not 
 be able to surmise, how the effect is brought about by the 
 action, or what intermediate steps there may be between the 
 action and the effect. Though we may not know anything of 
 the mechanism of a watch, how the action of winding afi"ects 
 the mainspring, or even that it has a mainspring, yet the 
 constant association, both in presence and in absence, of winding 
 and going compels us to conclude that there is a causal con- 
 nection between them. It is not material to the conclusion, 
 and does not affect the validity of the conclusion, whether or 
 not we know how the removal of the queen bee influences the 
 bees to rear another queen ; how the frost causes failure of the 
 
 f 
 
124 
 
 ON CAUSATION. 
 
 •^1 
 
 crop of fruit ; how incubation promotes the chick in the egg ; 
 how insects contrive to fertihse flowers ; how chimney-sweeping 
 causes cancer ; and so forth. These are, no doubt, useful and 
 valuable things to know, and until we know them our know- 
 ledge of the chain of causation is not complete : we know a 
 cause, but not the immediate cause. Nevertheless, we do 
 gain from observing association a very valuable knowledge of 
 causation, and a knowledge that, though it may not be complete, 
 is none the less certain as far as it goes. 
 
 The method of establishing constant association is the 
 method that Mill had confusedly in his mind when he formu- 
 lated his ridiculous Canons of Agreement and of Difference. 
 
 C. If the association is inconstant, it may be that the action 
 is sometimes attended by the effect and sometimes not, or .it 
 may be that the effect is sometimes attended by the action and 
 sometimes not. For the sake of brevity we will consider those 
 effects only that are changes. 
 
 If, on the action occurring, the effect sometimes follows and 
 sometimes does not, the action may be a cause of the effect, 
 but can be so in certain conditions only. 
 
 If the effect is sometimes preceded by the action and some- 
 times not^the action may be a cause of Jhe effect, but cannot 
 be the sole cause! ~~ , ^ '" 
 
 If, howeverTtlie association of the action with the effect, 
 although inconstant, is yet more frequent than casual concur- 
 rence will account for, the action must be the cause in some 
 cases. 
 
 No housekeeper has any doubt, or need have any doubt, that 
 thunder is causally connected with the beer turning sour. The 
 association is not constant. Beer does not always turn sour in 
 thundery weather, and sometimes turns sour when the weather 
 is not thundery; but still, considering how relatively rare 
 thundery weather is, and how relatively rare it is for the beer 
 to turn sour, the relative frequency of the conjunction is much 
 greater than mere casual concurrence will account for on the 
 Doctrine of Probability. The excess of cases of the association 
 over the number that casual concurrence will, account for 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 125 
 
 justifies the presumption, in that excessive number of cases, of 
 a causal connection. 
 
 The presumption that fog is a cause of bronchitis is entirely 
 justifiable, and is justified by the same principle. Not everyone 
 who is exposed to fog has bronchitis ; not everyone who has 
 bronchitis has been exposed to fog. Clearly, therefore, fog is 
 not a necessary cause of bronchitis : it can be a cause, if at all, 
 in certain conditions only ; and clearly, fog cannot be the only 
 cause of bronchitis. Nevertheless we may safely presume that 
 in certain conditions fog is a cause of bronchitis, because, 
 though the association is not constant, it is much more 
 ffequent than mere casual concurrence will account for. In 
 this instance the method of association grades off and merges 
 into the method of concurrent and proportional variation, for 
 not only is the number of cases of bronchitis increased whenever 
 there is a fog, which exemplifies the first method, but also the 
 number of cases of occurring bronchitis has a direct relation to 
 the severity and duration of the fog, so that there is to some 
 extent concurrent and proportional variation. The proportion 
 is, however, but very vague, for on the one hand, though we can 
 measure the duration of a fog, we cannC*, or do not, measure its 
 severity ; and on the other, though we register the number of 
 deaths from bronchitis, we do not register the number of cases 
 that occur ; and this vagueness in the proportion prevents us 
 from applying Method V (Concurrent and Proportional Varia- 
 tion) with any strictness ; and in fact our presumption, our 
 valid and justifiable presumption, that fog is one cause of 
 bronchitis rests in the main upon the observation that they 
 occur in association much more often than a casual concurrence^ 
 would account for. . 
 
 Many of the assigned causes of disease, and most of the 
 assigned causes of insanity, are assigned upon this principle 
 when they are assigned on any principle at all. No alienist 
 has any doubt that childbirth is a cause of insanity, nor need 
 he have any doubt, although by far the greater number of 
 childbirths are not followed by insanity, and by far the greater 
 number of attacks of insanity are not preceded by childbirth : 
 in fact, many cases of insanity occur in males, and could not 
 
 [is 
 
126 
 
 I* 
 
 \i 
 
 ,1 
 
 
 ON CAUSATION, 
 
 own this cause. The reasons which justify us in presuming 
 that childbirth is a cause of insanity are first, the rapidity with 
 which the insanity follows the childbirth, which goes some way 
 to bring the case under the first Method of ascertaining causes, 
 the xMethod of Instant Sequence ; and second, and mainly, the 
 fact that insanity and childbirth are associated together more 
 frequently than can be accounted for by casual concurrence. 
 That they are more frequently associated is always taken for 
 granted, and though it has never been avowed, or even dis- 
 covered, that it is this more frequent association that is the 
 warrant for our presumption of a causal connection, there is 
 not the slightest doubt that this is our warrant. Now that the 
 warrant is discovered, it will be easy to show how far it is 
 valid. The aggregate number of the female population of 
 child-bearing age in this country in any year is approximately 
 known. The number of child-births, and the number of women 
 of child-bearing age who become insane, are also known for any 
 one year. From these data it should be easy for any com- 
 petent statistician to calculate the number of child-bearing 
 women who would become insane, on the Doctrine of Proba- 
 bility, if child-bearing had no part in the causation of the 
 insanity. Any excess over this number of cases of insanity at 
 the puerperium must be due to child-bearing, provided, of 
 course, the numbers in the calculation are large. 
 
 Most of the cases in which heredity is alleged as a cause of 
 disease rest, though the assertors do not know it, upon the 
 same principle. Gout, insanity, phthisis, leprosy, cancer, and 
 other diseases, are found sometimes to occur in those whose 
 one or more relatives have suffered from the same disease ; and 
 when this is the case it is usually assumed without hesitation 
 that inheritance was the cause, or had a share in the causation, 
 of the disease. On the principle' now under discussion there 
 is no warrant for such an assumption unless the number of 
 cases occurring in one family is greater than would be normal 
 on the Doctrine of Probability, and unless also causal influences 
 proper to the families, and common to the several members or 
 the families, can be excluded. 
 
 While this principle, if applied strictly, and with caution to 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 127 
 
 ensure that the cases of association are actually more numerous 
 than they would be on the Doctrine of Chances, is sound, and 
 justifies the presumption that the association is causal in some 
 at least, though probably in some only, of the cases in which it 
 is found, yet, when this precaution is not taken, the method is 
 extremely likely to mislead, and is more often the ground of 
 false attribution of causes than perhaps any other method. 
 Nothing is more frequent than to find an action assigned as 
 the cause of an effect on no other ground than that of an asso- 
 ciation, which may have been merely casual, which may not be 
 more frequent than casual concurrence will account for, and 
 which may have been observed in but few cases, or even in but 
 one. It is perhaps the most frequent source of the fallacy of 
 arguing post hoCy ergo propter hoc. 
 
 D. Again, we may assume causal connection from association, 
 even though the association of the action with the effect is not 
 constant, if the associated effect has a constant peculiarity : if, 
 that is to say, whenever that action has preceded, the effect 
 has a certain quality, which is absent when the effect is not 
 preceded by that action. 
 
 Insanity often occurs in persons who have not drunk to 
 excess, or have even been total abstainers ; and often does not 
 occur in those who have drunk to great excess for many years. 
 The association between drinking to excess and insanity is 
 very inconstant. But when insanity does occur in those who 
 have long drunk to excels, it has certain features which are 
 peculiar — which are alike in all such cases, and are never seen 
 in the insanity of those who have not drunk to excess. This 
 constant quality in the effect warrants a confident presumption 
 that the cause in all such cases is similar; and as the only 
 constant preceding action is excessive drinking, we assign this 
 as the cause. 
 
 Similarly, there is no constant association between total 
 abstinence from alcohol and self-righteousness. There are 
 many total abstainers who are not self-righteous, and many 
 self-righteous persons who are not abstainers ; but when a 
 total abstainer is self-righteous, there is a smugness in his self- 
 
128 
 
 ON CAUSATION. 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 129 
 
 
 l^f 
 
 righteousness that is so constant that it warrants us in attri- 
 buting the self-righteousness to the total abstinence, or at least 
 in presuming a causal connection between them. 
 
 The handling of primula ohconica^ humea elegans, whitlavia 
 grandiflora, and certain other plants, is apt to be followed by 
 the appearance of nettle-rash on those who handle them. The 
 association is not constant : nettle-rash does not always follow 
 the handling of these plants, and often occurs in people who 
 have never been near any of them ; but when nettle-rash does 
 follow the handling of the plants, it has certain characters that 
 are the same in each case, and do not appear in other cases 
 of nettle-rash. Hence we may presume, from this constant 
 character, a causal connection between the nettle-rash and the 
 handling of the plants. 
 
 Rain often falls without the accompaniment of a thunder- 
 storm : thunderstorms sometimes occur without the accom- 
 paniment of rainfall ; but when rain does accompany a thunder- 
 storm, it has, in the large size of the drops, a peculiar character 
 by which it may be recognised, and which justifies us in pre- 
 suming a causal connection between the thunderstorm and the 
 f^rain. 
 
 This is as appropriate a place as any in which to examine 
 Mill's fourth Canon, which runs as follows : — * Subduct from any 
 phenomenon such part as is known by previous inductions to 
 be the effect of certain antecedents, and the residue of the 
 phenomenon is the effect of the remaining antecedents.' 
 
 Why Mill should have invented the word * subduct ' when he 
 had already to his hand the familiar words subtract and deduct, 
 it is not easy to say. Used by a latter-day philosopher, one 
 would surmise that it had been employed to conceal poverty of 
 thought, to strike awe into the mind of the reader, and impress 
 him with an expectation of the profundity of the wisdom and 
 penetration of what follows ; but Mill was too honest to have 
 recourse to such a stratagem unless he had first deceived him- 
 self, and this was probably the case. Passing this, we may 
 next notice that the method has no claim whatever to the title 
 of Experimental. The instance given, not by Mill, but by every 
 other authority, is the discovery of the planet Neptune, and 
 
 Mill, though he does not give this particular illustration, gives 
 others from the science of astronomy. But no experiment was 
 employed in the discovery of Neptune, nor is it possible to 
 experiment with the positions of the planets or the stars. This 
 Experimental Method for the discovery of causes is therefore 
 neither experimental, nor is it employed in the discovery of 
 causes. We have already seen that it was not the method by 
 which Neptune was discovered, and if we analyse the instances 
 that are adduced by Mill and other writers, we shall find that 
 in not one case has the cause of anything ever been discovered 
 by the Method of Residues. I do not say that it is impossible 
 to discover a cause by this method, though I think it very 
 unlikely that it can be done ; but it has certainly not been done 
 yet. All that has ever been discovered by the method is that 
 there is something new to be accounted for, something of which 
 the cause is not yet known, and then the cause of this new 
 * phenomenon ' is discovered by one of the methods set forth 
 in this Chapter, but not by the Method of Residues. 
 
 V. Concurrent Variation. 
 
 Causal connection may be established by the discovery of 
 concurrent and proportional variation of action and effect ; and 
 is the more warrantable the closer the concurrence and the 
 more exact the proportion. 
 
 This is a very far-reaching method, and though its employ- 
 ment is seldom in comparison with some of the other methods, 
 it gives results when their employment is impracticable. In 
 'some cases, as will be seen in the examples adduced hereunder, 
 it is impossible to trace any action upon the thing changed, but 
 the concurrent and proportional variation of the action and the 
 change impels us irresistibly to conclude a causal connection 
 between them. 
 
 The method, as stated above, replaces Mill's Method of Con- 
 comitant Variations, which, as he states it, is manifestly false. 
 His fourth Canon runs : 
 
 * Whatever phenomenon varies in any manner whatever 
 whenever another phenomenon varies in some particular 
 
130 
 
 ON CAUSATION. 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 i 
 
 manner, is either a cause or an effect of the phenomenon, or is 
 connected with it through some fact of causation.' 
 
 This Canon is, if possible, more ludicrously inept than the 
 others, but it has nevertheless been endorsed by every writer 
 of the school of Mill since he first stated it. According to this 
 Canon, if the weather varies in any manner whatever whenever 
 a child is growing, then the weather is either a cause, or an 
 effect of the child's growth, or is connected with the child's 
 growth through some fact of causation. Similarly, if the tide 
 varies in height when the corn is ripening ; if the fashion in 
 women's dress * varies in any manner whatever ' whenever 
 icebergs are unusually numerous in the Atlantic ; if slugs 
 become very numerous when Halley's comet reappears; then 
 these * phenomena ' are connected through some fact of causa- 
 tion. Manifestly, it is not enough that the one * phenomenon ' 
 should vary in any manner whatever ; such a stipulation is of 
 no value, as any child can see. The one phenomenon must 
 vary proportionally with the other. The proportion need not 
 be exact, but some proportion there must be between the two 
 occurrences or changes to enable us to presume a causal con- 
 nection ; and the more exactly the proportion is maintained, 
 and the closer in time the one change to the other, the more 
 confidently we may presume the connection. 
 
 The most familiar instance is the concurrent and propor- 
 tional variation between the turning of a tap and the flow of 
 water or the size of the gas flame. As the tap is turned more 
 and more towards the straight position, so, concurrently and 
 proportionally, does the flow of water increase in volume or 
 the flame increase in size. As the tap is turned more and 
 more towards the cross position, so, concurrently and propor- 
 tionally, does the flow of water or the size of the flame 
 diminish. The variation is not exactly proportional through- 
 out the whole range. When the tap is near the straight posi- 
 tion, the additional effect produced by additional alteration is 
 less than when it is near the cross position ; and when it is 
 straight, or nearly straight, slight alterations of position have 
 no answering alterations in the flame or the stream of water ; 
 but still, on the whole, the variation in the size of the flame or 
 
 131 
 
 i! 
 
 the stream are so closely concurrent with the variations in the 
 position of the tap, and generally observe so strict a proportion, 
 that a bystander who had never before seen a tap or a gas 
 liame would be compelled to presume the causal connection, 
 and would feel his conclusion the more inescapable, the more 
 often he saw the experiment repeated. Still more assured would 
 his certainty become when he found that the more rapid or the 
 slower the action, the more rapid or the slower was the effect, and 
 that any interruption of the one was attended by interruption 
 of the other. Concurrence so close, and generally so closely 
 proportional, would carry to his mind the irresistible conviction 
 of causal connection. It is true that in this case our conclusion 
 is partly derived by the Method of Instant Sequence, but, as 
 will be more fully shown hereafter, we usually employ more 
 than one method. 
 
 The great importance of the method of concurrent and pro- 
 portiond j^nation is that it can be applied when no other 
 "method of ascertaining causation is applicable, when experi- 
 mentation is impossible, and even when the means by which 
 the effect is produced are beyond our knowledge and beyond 
 conjecture. It is by this method that a causal connection has 
 been established beyond all doubt between spots in the sun 
 and magnetic storms on the earth, a causal connection that 
 could not possibly have been established in any other way. It 
 is by this method that a causal connection has been established 
 beyond all doubt between the tendency of mankind to suicide 
 and the length of the day. The number of suicides in Europe, 
 and the proportion of suicides to the population, have been 
 found to be subject year after year to seasonal variations. The 
 number of suicides is lowest in December, when the days are 
 shortest, and highest in June, when the days are longest. The 
 proportional variation is not exact : if plotted on a curve, the 
 curve would be irregular, and would vary from year to year and 
 from country to country : but still, taken over many years and 
 in many countries, the number of suicides increases with an 
 approach to regularity, month by month from the winter 
 solstice, until, when the summer solstice is reached, the number 
 is doubled, and it then declines again irregularly through the 
 
 V 
 
132 
 
 ON CAUSATION. 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 133 
 
 r 
 
 
 .*« 
 
 iili 
 
 pi? 
 
 summer and autumn months to its minimum in November and 
 December. Since the proportion is not exactly maintained, 
 it is clear that other influences are at work ; but since the 
 proportion obtains generally year by year in every European 
 country, we are compelled to presume a causal connection 
 between the number of suicides and the length of the day, even 
 though we are utterly unable to conjecture the manner in which 
 the causal influence is exerted. It is clear that the number of 
 suicides cannot affect the length of the day ; and w^e cannot 
 suppose that longer hours of daylight affect the mind of the 
 potential suicide so as to confirm his purpose. Through what 
 devious channels the causal influence travels we cannot conjec- 
 ture ; but that the length of the day is in some way causally 
 connected with the number of suicides we cannot doubt. 
 
 In such a case as has just been examined, the facts are 
 beyond doubt, and admit of no uncertainty ; but the method 
 requires care in its application, and is open to more oppor- 
 tunities for error than any other method, for this reason among 
 others, that it is employed usually in cases that are complex 
 and intricate; in cases in which many causes, some perhaps 
 unsuspected, may be contributing to a result; in cases in which 
 other methods cannot be employed to check and control our 
 conclusions ; and also because it usually depends on the collec- 
 tion of statistics, with all the numerous and inevitable errors to, 
 which the collection of statistics is liable. The manipulation 
 of numbers is perhaps the most accurate process of which the 
 human intellect is capable. Given a set of numbers to start 
 with, every step in calculation can be checked with the most 
 rigid exactness, so that it is scarcely possible for two competent 
 calculators to arrive at different results ; but the apphcability 
 of these results, and the correctness of the inferences to be 
 drawn from them, depend entirely on the correctness of the 
 original figures from which the start was made, and this is 
 usually sadly to seek. It is easy, for instance, to establish a 
 concurrent and proportional variation in the amount of drunken- 
 ness in a community and the number of crimes committed in 
 that community, and hence to establish a causal connection 
 between drunkenness and crime ; but consider the methods in 
 
 which the statistics of crime and of drunkenness are collected. 
 
 The statistics of crime are taken from the records of the police, 
 
 but different chief constables have very different views of what 
 
 should constitute an offence * known to the police ', and their 
 
 statistics will vary accordingly. When loss of property is 
 
 reported to one chief constable, he enters it at once as a theft. 
 
 If it is subsequently discovered to have been an accidental loss, 
 
 it is taken out of the class of thefts ; but if the manner of the 
 
 loss is never discovered, the loss remains recorded as a theft. 
 
 Another chief constable will not enter a loss as a theft unless 
 
 there is good reason to believe that the property has been 
 
 stolen ; and a third will not enter anything as a theft unless 
 
 the thief has been caught and prosecuted, and a conviction 
 
 obtained in a court of justice. It is clear that to compare with 
 
 one another the statistics of theft in these three districts would 
 
 be absurd. Again, in a district in which the Watch Committee 
 
 contains a large proportion of teetotalers, and the magistrates 
 
 take a stern view of drunkenness, the number of drunkards 
 
 apprehended, or summoned, and convicted will be at a maximum. 
 
 In an adjoining district, in which the amount of drunkennesss is 
 
 not less, or may even be greater, but in which the police have 
 
 instructions to look leniently on slight departures from sobriety, 
 
 and rather to see a man home or to put him in care of a friend 
 
 than to arrest him, and in which the magistrates are prone to 
 
 give offenders the benefit of any doubts they may entertain, the 
 
 statistics of drunkenness may be less by a third, or even a half. 
 
 Again, ' serious ' offences are those which are tried at assizes 
 
 or quarter sessions : ' trivial ' offences are those disposed of in 
 
 ^ courts of summary jurisdiction ; but in many cases the offender 
 
 has an option whether he will have his case disposed of by the 
 
 magistrate, or whether he will elect to go for trial; and in 
 
 exercising this option he will be influenced by the reputation of 
 
 the magistrate for leniency or severity ; and in this case again 
 
 the statistics of ' serious ' crime in the jurisdiction of one 
 
 magistrate are not comparable with those of such crime in the 
 
 jurisdiction of another. Differences such as these are seldom 
 
 allowed for by the statistician. In his eagerness to have a set 
 
 of figures to manipulate, and to produce a result that shall be 
 
 
134 
 
 ON CAUSATION. 
 
 
 , i 
 
 * mathematically accurate ', he is too often blind to the initial 
 errors of the figures that form the basis of his calculations. 
 
 In most cases, variation, when concurrent and proportional, 
 is so within certain limits only, and unless these limits are 
 observed the causal connection will be stated too absolutely, as 
 in fact it usually is. Within certain limits, the rate at which a 
 plant grows is concurrent and proportional to the temperature ; 
 but there is a certain lower limit of temperature at which the 
 plant will not grow at all, and however much this limit may be 
 exceeded, the growth of the plant exhibits no proportional varia- 
 tion ; and there is a certain higher limit at which the plant 
 suffers damage, and will not grow, and however much this limit 
 may be exceeded, the growth of the plant exhibits no pro- 
 portional variation. Within certain limits, the consumption of 
 a commodity varies in inverse proportion to the price ; but 
 there is a certain lower limit of price at which the consumption 
 is at a maximum, and however much the price may be lowered 
 beyond this limit, the consumption will not increase ; and there 
 is with many commodities a certain price at which the con- 
 sumption of that commodity is at a minimum, and however 
 much beyond this the price may be increased, the consumption 
 of the commodity will not diminish. Within certain limits, 
 the amount of work that a man can do varies concurrently and 
 proportionally with the amount of food he eats; but there is in 
 the quantity of that food a certain lower limit at which he can 
 do no work, and no diminution of the food below this limit can 
 diminish his work ; and there is in the quantity of this food a 
 certain upper limit at which he can do the maximum of work, 
 and any increase beyond this does not increase, but diminishes, 
 the quantity of his work. This limitation of the application of 
 the method of concurrent and proportional variation, obvious 
 as the limitation is, has never been noticed by any writer on 
 the subject ; but then no one but logicians have written on the 
 subject, and, as I have said elsewhere, logicians are blind to the 
 obvious, naturally blind ; but they must have taken great pains 
 not to see many of the things they neglect. Such an excess 
 of unobservation is not in nature. 
 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 VI. Common Rarity. 
 
 135 
 
 If an unusual effect is associated with an unusual action, we 
 are apt to assume a causal connection between them, and the 
 assumption has the more justification the more unusual both 
 the action and the effect are. 
 
 In the early '8o's of the last century there was a terrific 
 volcanic eruption at Krakatoa, in Java, a great part of the 
 mountain being blown up and dissipated. An eruption of such 
 violence had not occurred in historic times. Weeks afterwards 
 there occurred in this country, and indeed almost the world 
 over, a prolonged series of most wonderfully coloured sunsets, 
 such as no one living had ever witnessed before. This extremely 
 unusual effect was connected by its very rarity with the 
 extremely unusual volcanic action, far away as that action was ; 
 and it was argued, and the argument was generally accepted, 
 that the gorgeous sunsets were due to the presence in the air of 
 an unusual quantity of impalpably fine dust, which had been 
 projected into the upper regions of the air by the explosion of 
 the volcano, and had floated to distant parts of the earth. It 
 was the common rarity of the action and the effect which 
 suggested a causal connection between them. 
 
 In the great frost of 1686 many great trees suddenly split 
 from top to bottom with a loud report like that of a cannon. 
 Our ancestors did not know how the frost could produce this 
 effect ; but it is a very rare occurrence, and so intense a frost 
 was a very rare occurrence ; and the common rarity of the two 
 events led to the assumption that they were causally connected, 
 and that the frost was the cause of the splitting of the trees. 
 
 In sparsely populated countries the advent of a visitor is a 
 rare occurrence. If, after such an occurrence an object is found 
 to be missing, and this also is a rare occurrence, causal con- 
 nection between the occurrences will be presumed on the 
 ground of their common rarity. 
 
 In the very exceptionally severe winter of 1895, seagulls 
 appeared for the first time as far inland as London Bridge. 
 The common rarity of the two events pointed inevitably to a 
 causal connection between them. 
 
 I 
 
smsrs 
 
 ^s^ 
 
 
 136 
 
 ON CAUSATION. 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 137 
 
 ^ti 
 
 I: 
 
 4 
 
 !l! 
 
 
 r.i 
 
 r? 
 
 VII. Corresponding Qualities. 
 
 Any peculiar quality in an effect points to a corresponding 
 quality in the agent that produces the effect. 
 
 This principle is very frequently employed in practice, so 
 frequently that it is puzzling that writers on causation have 
 overlooked it. Like several of the other methods here described, 
 it jumps up and hits in the face anyone who gives a moment's 
 consideration to the subject ; and like others of the methods, it 
 has been familiar to us from our earliest years. The leading 
 case is that of Robinson Crusoe and the footprint. When he 
 saw the footprint in the sand, did Crusoe wait until he had seen 
 two or more instances of the phenomenon having only one 
 circumstance in common, and two or more instances in which 
 the phenomenon was absent having nothing in common but 
 the absence of that circumstance ? Not being a logician or a 
 lunatic, he did nothing of the kind. He said at once * A man 
 has trodden here.' What was his justification for this conclu- 
 sion ? It was that he saw in the print certain peculiar qualities 
 which pointed irresistibly to corresponding qualities in the 
 agent that produced the print. These peculiar qualities in the 
 print corresponded with peculiar qualities of the human 
 foot. No other agent possesses them. The inference was 
 inescapable that the human foot was the agent that produced 
 the print. 
 
 This method is particularly valuable when it is desired to 
 identify, not so much the cause, as the agent that has produced 
 a certain effect. It is therefore especially used by the police in 
 criminal investigations, in which the cause, human agency, is 
 already known, and what is desired is to identify the agent. 
 The modern method of criminal investigation, devised by Major 
 Atcherley, the Chief Constable of the West Riding, is avowedly 
 founded on this principle. He takes it as an accepted fact that 
 no two men are exactly alike, and that the differences, small but 
 easily distinguishable, that enable us to identify the face and 
 figure of every man, and to distinguish him from his fellows, are 
 paralleled by differences that, if small, may be distinguished by 
 skilled and trained observation, between their modes of action. 
 
 r 
 
 Thus it is found that each criminal has his own special depart- 
 ment of crime, to which he confines himself wholly or mainly. 
 One is a burglar, another a pickpocket, another 'a long firm 
 swindler, another an area sneak, another a perpetrator of the 
 confidence trick, and so on. More than this, each pickpocket, 
 each burglar, each long firm swindler, and so on, has his own 
 minor peculiarities of action, which leave their peculiar impress 
 on the effects that he produces ; so that, given all the details 
 of the effects produced by a crime, it is usually possible to con- 
 clude which particular criminal known to the police has 
 committed it. 
 
 In order to secure a conviction, however, it is not enough 
 that the police should know what criminal has committed the 
 crime ; it is necessary in addition that they should have 
 evidence to lay before the jury connecting the criminal, as 
 agent, with the crime as effect or result. This can only be done 
 by proving some peculiar quality in the crime, or in some 
 accompaniment, part, or condition of the crime, that corre- 
 sponds with a peculiar quality, either in the agent himself, or in 
 some instrument peculiar to him. 
 
 Thus, if a wound has such qualities as show that it was inflicted 
 by the left hand, and the accused is left-handed, the conjunc- 
 tion is evidence against the accused; but since left-handedness, 
 though unusual, is not peculiar to the accused, he should not 
 be convicted on this evidence alone. If, however, the print of 
 a bloody hand shows that the criminal had lost half the second 
 finger and the whole of the third, and if the accused has lost 
 these parts, then he must be convicted, for such qualities are 
 peculiar to him. It is on this principle that the evidence of 
 finger marks is conclusive of the presence of the person with 
 whose fingers they correspond ; for the finger markings of each 
 individual person are peculiar to him alone. 
 
 If a jemmy found in the possession of the accused exactly 
 fits marks on a door that has been prized open, the jemmy is 
 evidence against the accused ; but it is not proof, for many 
 jemmies may be made of the same bar of steel, and many bars of 
 steel by the same rollers, and therefore the quality of the jemmy 
 would not be peculiar or proper to that jemmy ; but if the edge 
 
 m 
 
 
I 
 
 (.1 
 
 14 
 
 138 ON CAUSATION. 
 
 of the jemmy is chipped and shows a notch, and if the mark on 
 the door fits the edge of the jemmy, notch and all, then the 
 identification of the jemmy, as the agent that produced the 
 effect, is beyond doubt, for now the corresponding qualities of 
 the effect and the agent are peculiar. 
 
 When Crippen was accused of the murder of his wife, certam 
 human remains were found in his cellar wrapped in pyjamas. 
 So far this was no evidence against Crippen; but it was 
 subsequently proved that he had bought those very pyjamas ; 
 and thus an instrument of the crime was shown, by the 
 possession of peculiar qualities, to have been in his ownership. 
 An anonymous letter, typewritten throughout, is received. 
 The script is that of a common make of typewriter, and is not 
 peculiar ; but every impression of one of the letters exhibits a 
 certain defect. If a typewriter can be found having that 
 peculiar defect in that letter, then there is no doubt that this 
 typewriter was the agent employed, and that the person who 
 wrote the anonymous letter had access to that typewriter. 
 
 A gardener finds his seedlings gone, and on the soil on which 
 they grew he finds a shining track of dried slime. He concludes 
 at once that the agent that has taken his seedlings is a slug, 
 for the quality of the shining track is peculiar, and corresponds 
 with the peculiar quality of slugs of leaving such a trail behind 
 them. He knows, moreover, that slugs have an appetite for 
 seedlings, having often lost seedlings by slugs before. Thus by 
 a combination of the Method of Corresponding Qualities with 
 the Method of Similarity he concludes that the criminal that 
 stole his seedlings was a slug. 
 
 It is usual in English parks to see all the trees, however 
 irregular the rest of their outline may be, present a flat surface 
 towards the ground, at the same distance from the ground in 
 every tree. The common effect points to a common cause : the 
 peculiar quality of the effect points to a peculiar quality in the 
 agent : the agent must be one that can reach to just the height 
 from the ground at which the foliage terminates ; and the only 
 such agents that have access to the trees are the cattle or deer 
 that are pastured in the park. 
 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 VIII. Coincidence in Area. 
 
 139 
 
 ^ If an action has taken place on a certain area of a thing, and 
 if subsequently a certain effect is found to be precisely limited 
 to that area, then we may confidently presume that that action 
 was the cause of that effect. It is more frequent, however, to 
 infer from coincidence of area the influence of a condition 
 than that of a cause, and in many cases the distinction is 
 practically unimportant. 
 
 When a picture that has long been hanging on a wall is 
 taken down, it is usual to find the area of wall paper that was 
 behind the picture deeper in colour than that of the surround- 
 mg wall paper, and the area of the deeper colour coincides with 
 the area of the picture. In such a case we are driven to the 
 conclusion that the prolonged presence of the picture in that 
 place was a condition of the retention of its colour by the 
 paper behind. 
 
 If in summer a drain is laid across a lawn, and the ground 
 is filled in, and the turf relaid, it may be found in the 
 following winter that hoar frost is thick upon the ground over 
 all the rest of the lawn, but that the line over the drain is free 
 from frost. The coincidence in space compels us to presume 
 that the altered state of the ground brought about by laying the 
 drain is a condition of the non-appearance of the frost, and that 
 the action of laying the drain was an indirect cause of this 
 unchange. 
 
 It sometimes happens that a rash appears on a person's legs 
 exactly up to the level of the top of his stockings, and there 
 ceases abruptly. Such coincidence in area compels us to pre- 
 sume that the wearing of the stockings is a condition of the 
 effect, the putting of them on an indirect cause of the 
 effect, and the action of something in the stockings the direct 
 immediate cause of the effect. 
 
 In experimental agriculture it is a frequent practice to sow 
 an area of soil uniformly with a certain kind of seed, after 
 different portions of the area have been treated with different 
 manures, and one portion of the area with none. Any difference 
 m the crop which is uniform over one portion so treated, and 
 
(ill 
 
 
 Pi 
 
 i i 
 
 
 il*' 
 
 
 140 
 
 ON CAUSATION. 
 
 coincides with the area treated, is presumed to be due to the 
 presence of the manure in that area, which was a condition, as 
 the manuring was an indirect cause, of the result. 
 
 It has been found that the vegetation of a meadow is ditterent 
 in two narrow parallel lines a few inches wide, extending from 
 one gate across the meadow to another. When it was remem- 
 bered that a cart was driven across the meadow from one gate 
 to the other, and that the lines of different vegetation coincide 
 with the cart track, it could not be doubted that the traverse 
 of the cart was the cause of the difference in the vegetation. 
 
 The area over which the action extends, and to which the 
 effect is limited, need not be continuous. 
 
 Every gall that grows on trees or plants is found to contain, 
 or to have contained, the larva of an insect. It is therefore 
 presumed that the presence of the larva in the gall is causally 
 connected with the formation of the gall. From other sources 
 of information we know that in each case the larva grows 
 from an egg that has been inserted by the mother insect into 
 the tissues of the plant. As galls do not grow on any part of 
 a plant into which an egg has not been inserted by an insect, 
 the coincidence in area, of the attachments of the galls with the 
 places into which eggs have been inserted, compels us to presume 
 that it is the operation of inserting the egg, or something 
 accompanying that operation, which is the cause of the galls. 
 
 The same principle is constantly employed in the physio- 
 logical and pathological laboratory. To find the physiological 
 action of a food or a drug, two animals as nearly as possible 
 alike are taken, and placed under similar conditions. The food 
 or drug is then administered to one, and not to the other ; and 
 any phvsiological change that is limited to the one to which the 
 food or^drug has been administered is presumed to be due to 
 
 the administration. 
 
 Similarly, in experimenting on or with bacteria, two or more 
 test-tubes or surfaces are taken, and are treated similarly in 
 every respect but one. Whatever difference ultimately appears 
 between them is held to be due to the one respect in which 
 they were differently treated. 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 IX. Coincidence in Time. 
 
 141 
 
 As the method of Instant Sequence is limited in application 
 to the discovery of those effects, or of the causes of those effects, 
 that are changes, so the method of Coincidence in Time is 
 limited to the discovery of the causation of those effects that 
 are unchanges ; with this exception, that by the latter method 
 we may sometimes identify the agent that produces repeated 
 instances of change. This we do by ascertaining the presence 
 during the whole time these effects are being produced, of a 
 certain agent, or of similar agents. 
 
 If, upon making a manure heap near a house, that house 
 becomes infested by a plague of flies, and if, upon the removal 
 of the manure heap, the plague is stayed, then we should 
 presume a causal connection between the manure heap and the 
 flies, even if we did not know that flies breed in manure. 
 
 How do we gain the belief that sea-sickness is due to the 
 motion of the boat ? The sole foundation for the belief is in 
 the coincidence in time of the motion with the unpleasantness. 
 
 How do we know that the din of a factory is due to the 
 motion of the machinery ? Partly, no doubt, by Subsumption 
 of the case under the law that all noise is due to motion ; 
 partly by the method of Concurrent and Proportional Varia- 
 tion, since the nearer we approach to the apartment in which 
 the machinery is, the louder the noise becomes, and vice versa ; 
 but mainly by the knowledge that when the machinery starts 
 the noise begins; that the noise continues as long as the 
 machinery is going ; and subsides into silence the instant the 
 machinery stops. 
 
 How do I know that the draught that is blowing my papers 
 about comes from the open window ? By observing that it 
 began the moment the window was opened, continued as long 
 aS'- the window remained open, and ceased as soon as the 
 window was shut. 
 
 It is necessary, I suppose, to adduce an instance from 
 * science,' and therefore I may here point out that the 
 causation of magnetic storms by sunspots, which is ascertained 
 partly, as already shown, by the method of Concurrent and 
 
142 
 
 ON CAUSATION. 
 
 f 
 
 i: 
 
 
 1^/ 
 
 Proportional Variation, receives corroboration from the method 
 now under consideration, of Coincidence in Time. ^ 
 
 If a number of thefts take place in a house, and if, upon one 
 of the servants leaving the house, the pilferings cease, and 
 especially if it is then remembered that the pilferings did not 
 begin until after that servant entered the house, the presumption 
 is very strong that that servant is the pilferer. In this case the 
 coincidence in time is not between a cause and an effect, but 
 between the presence of an agent and a series of effects. 
 
 If it is found that explosions in coal mines coincide in time 
 with depression of the barometer, the presumption is raised that 
 the lowness of the pressure of air has a causal influence on the 
 explosions. It is evident that, while from one aspect this may 
 be regarded as a case of Coincidence in Time, from another 
 aspect it may be regarded as a case of Association. 
 
 These, then, are the nine or twelve circumstances that warrant 
 us in presuming a causal connection between an action, an 
 agent, or a condition, and an effect or result. Any one of them, 
 if fully established, justifies the presumption of causation or of 
 causal connection, but in practice we rarely limit ourselves to 
 one method, and in practice, moreover, they are not as distinct 
 as they are here made to appear by systematic description and 
 somewhat artificial separation. When we seek to discover a 
 cause, or a condition, or an agent, we use what means we can ; 
 and it is only after our reasonings are complete that we are 
 able to analyse them, and to extricate from the various con- 
 siderations that influenced us the separate elements that are 
 here disentangled and separately displayed. In practice they 
 are no more pursued in isolation from one another than deduc- 
 tion and induction, fundamentally different as they are, are 
 employed in isolation from each other. Few of the methods 
 of ascertaining causation can be employed quite separately, for 
 as most of them have a common origin in the Axiom of 
 Causation, they are not wholly different, but merge and blend 
 into one another; what separation they have being largely 
 artificial, so that a given instance may often be ranked under 
 one or another method according to the way in which we 
 
 w ' f^: ?^' : J^gw^ . w 'iB W-wjia^ ' gHiHf iiBaBTi 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 143 
 
 •contemplate it, and according to the feature to which we give 
 prominence. The only methods that are not derived from the 
 Axiom of Causation are the Method of Instant Sequence, the 
 Method of Coincidence in Time, and the first application of 
 the Method of Association. It will be interesting to inquire 
 what grounds we have for inferring causation by the use of 
 these methods. 
 
 What warrant we have for concluding that a change in a 
 thing that instantly follows upon an action on that thing is the 
 effect of the action, is not immediately apparent. Few con- 
 victions are more firmly and deeply rooted in our minds, and 
 at a very early age too, as we see when the baby in arms blows 
 upon a watch. Having seen the change follow once, the child 
 concludes that it is the effect, and that it does draw this 
 conclusion is proved by the child repeating the action with the 
 evident intention of seeing the change repeated. If the 
 sequence, of a change in a thing occurring instantly upon an 
 action on that thing, were constant in experience, the empirical 
 ground of the conviction would be manifest and would be sure ; 
 but there is no such constancy in experience. We frequently 
 witness actions that are not instantly followed by perceptible 
 changes in the thing acted on, and we frequently witness 
 changes m things that are not instantly preceded by perceptible 
 action on the thing changed. The experience of instant 
 sequence is no doubt frequent ; but it is by no means constant 
 in experience. The real ground of the inference is, I believe 
 in our experience of our own acts—in the changes in our own 
 bodies that instantly follow the exertion of our wills, and in the 
 changes instantly produced both in things around us and in 
 ourselves by our own acts. The first sequence is strictly 
 constant in experience. Our own movements instantly follow 
 the action of our wills, and never in health take place except 
 m instant sequence to volition. It is often objected that this 
 cannot be the origin of our notion of causation, because we do 
 not know how the mental operation of the will can produce a 
 bodily movement ; but this is beside the question. Such 
 knowledge is quite unnecessary for the origin of the notion 
 It IS enough for us that the exertion of the will is to us an 
 
144 
 
 ON CAUSATION. 
 
 METHODS OF ASCERTAINING CAUSES. 
 
 I4S 
 
 action It is an exertion of the activity of the self, and is not 
 only to us an action, but is, I believe, the ultimate source of 
 our notion of action. And it is, to us, an action on our bodies 
 and limbs. Whether the will does or can act upon the body, 
 and if so by what means, is beside the question. It is indis- 
 putable that it seems to us to do so, and that, until our minds 
 are sophisticated by the teaching of philosophers, it is to us as 
 unquestionable a certainty as the existence of an external world 
 or as our own existence. The second sequence also, that ot 
 the instant changes that follow our own acts on things around 
 us, is constant in experience. It is true that some of our 
 actions on things around us are not instantly followed by- 
 perceptible changes in them, as when we hit a brick wal with 
 the fist, but there is always an instant change either m them, 
 or in ourselves, or in both. Even when we hit a brick wall 
 with the fist, the action is instantly followed by the sound ot 
 the blow and by the pain of the blow. I think, therefore, that 
 the ground of our belief in the causation of a change that 
 instantly follows an action is empirical, and is based, as so many 
 of our most certain convictions are based, upon the enumeratto 
 
 simplex. , , , . .• 
 
 That we should argue causation from Isolated Action is more 
 easily explained. We come to the instance with the conviction 
 in our minds that a change in a thing must be due to an 
 action on that thing ; and if the change is preceded by one 
 action only, or by but one material action, that action must be 
 
 the cause of the change. . 
 
 The method of Coincidence in Time rests upon the manifest 
 connection that this coincidence establishes. A cause is an 
 action connected with a change or unchange in the thing acted 
 on If we can establish a coincidence in time between the 
 unchange and an action, we have gone far to identify the cause; 
 for, as already shown, the action that causes an unchange is 
 necessarily contemporaneous with the unchange, and begins, 
 continues, and ends with the unchange. 
 
 All the other methods derive their validity from the funda- 
 mental Axiom of Causation, that like causes in like conditions 
 ■produce like effects. The Method of Assimilation is the direct 
 
 application of the principle. Subsumption under a general 
 law is a direct, but a wider application of it, to cases funda- 
 mentally similar though superficially different. It is effected 
 by establishing similarity in material features between the 
 case in hand and the cases assembled under the law. Constant 
 Association of the action with the effect means the constant 
 association of similar action with similar effects, so that if 
 one pair is causally connected, the other pairs are causally 
 connected. 
 
 Constant Association of an action with some quality in the 
 -effect comes under the same rule. An association that is 
 more frequent than casual concurrence will account for again 
 implies the comparison and assimilation of cases, and assumes 
 that in similar conditions similar effects are produced by 
 similar causes. The Method of Concurrent and Proportional 
 Variation rests upon the assumption that not only do like 
 causes in like conditions produce like effects, but also like 
 differences in causes produce like differences in effects ; and 
 similarly, the other Methods manifestly obtain their validity 
 from the same fundamental axiom, or from some derivative 
 of it. 
 
 It follows that the methods, being founded upon the same 
 principle, and being but different applications of the same 
 principle, are not only fundamentally similar, but merge and 
 blend into one another, so that not only may we employ 
 more than one concurrentlv, but also the method that we 
 employ in any individual case may often be relegated to one 
 or another of the twelve methods, according as we choose to 
 regard it, or according as we lay stress on this or that feature 
 in our method. The Method of Coincident Areas, for instance, 
 may be regarded as a case of the Method of Association. It 
 may be called a case in which the addition alone of an action 
 is followed by an effect, or the withdrawal alone of an action 
 is followed by the disappearance of an effect. In this way of 
 stating the matter, however, the time element is brought into 
 prominence; but in applying the Method of Coincident Areas 
 we drop the time element out of consideration, and found our 
 conclusion directly upon the coincidence in space which is a 
 
 10 
 
 ■»■.»■ ijf 
 
 ■j^H ^^^Ij^t^ f t**^-*^ 
 
 I 
 
 i 
 
I 
 
 146 
 
 ox CAUSATION. 
 
 hi 
 
 \4 
 
 
 Ui 
 
 
 fc: 
 
 guide or indication to the presence or absence of the action. 
 The Method of Common Rarity is, in one aspect of it, another 
 instance of the first Method of Association. Seeing that Like 
 effects in like conditions are always owing to like causes, it 
 follows that a rare effect must be due to a rare cause or to 
 rare conditions ; and when it is preceded by a rare action we 
 are justified in associating the rare action with the rare effect, 
 because common actions can be excluded if the conditions are 
 common. It is possible, therefore, to diminish the num.ber of 
 methods, but only at the cost of exercising a certain amount 
 of ingenuity in bringing seme under others ; and it would be 
 possible to increase the number, but only by making dis- 
 tinctions scarcely worth making, and at the cost of increasing 
 the burden on the memory. As they are stated, they present 
 a useful and practical compromise. 
 
 Stniwiary. 
 
 The methods of ascertaining causation used by scientific 
 men in scientific matters are precisely the same as those used 
 by everyone else in the common affairs of daily life, and are 
 nine in number, one of them including four distinct methods, 
 so that there are twelve in all, as follows — 
 I. Instant Sequence. 
 II. Subsumption under a general law. 
 
 III. Assimilation. 
 
 IV. Association. 
 
 A. When sole, or isolable. 
 
 B. When constant. 
 
 C. W^hen too frequent to be casual. 
 
 D. When attended by a constant peculiarity 
 
 in the effect. 
 V. Concurrent and Proportional Variation. 
 VI. Common Rarity. 
 VII. Corresponding Qualities. 
 VIII. Coincidence of Area. 
 IX. Coincidence in Time. 
 These are here substituted for Mill's four Methods of 
 
 METHODS OF ASCERTAINING CAUSES. i^^ 
 
 Experimental Enquiry, which are not four, but five- some 
 of which cannot be, and none need be, experimental, and none 
 of which ever has been used or ever could be used Mill's 
 methods are examined and found to be all absurd, and one 
 of them unintelligible. 
 
 Each of the methods above enumerated is examined, and 
 shown by illustrative examples to be in use for the discovery 
 of causes, both in scientific and in other matters. In practice it 
 IS usual for more than one method to be employed without 
 discrimination in the same case ; and as all but three of them 
 are founded on the Axiom of Causation, separate discrimination 
 ot any but these three is to some extent artificial. 
 
 M 
 
ERRORS IN ATTRIBUTING CAUSATION. 
 
 149 
 
 'A 
 
 if 
 
 If; 
 
 M 
 
 CHAPTER VII. 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 Causation has been defined as the connection between 
 
 action on a thing and the sequent change or accompanying 
 
 unchange in the th.ng acted on. It follows that m order to 
 
 prove causation we must prove ^u,„„pH 
 
 (1) Action on the thing changed or mamtamed unchanged. 
 
 (2) Sequence of the change on the action, or contemporaneous 
 
 action and unchange. t, „= ,^,. 
 
 (3) Connection between the action and the change or 
 
 unchange. 
 
 It follows also that the following blunders in attributing 
 causation are possible, and in fact they are often committed, 
 (i) An agent may be taken for a cause. 
 (2) The agent may not exist. 
 
 (:0 The action may not exist. , . , , rr ^ • 
 
 (4) The action may not be on the thing in which the effect is 
 
 ^'trii^ action on the thing changed may not be connected 
 
 with the change. 
 
 (6) The action may not precede the change or accompany 
 
 the unchange. 
 
 (7) A condition may be taken for a cause. 
 
 (I) A cause is an action, and an action implies an agent. 
 It would seem, therefore, that the first step in discovermga 
 
 
 cause is to discover the agent ; but this is not necessary. A 
 cause is an action, and when we have identified the action that 
 causes the effect, we know the cause, and need not go behind 
 it to discover the agent. Before the discovery of gravitation, 
 the action of the earth, in attracting bodies on its surface 
 towards the centre, was as well known as it is now, but 
 that action was attributed, not to the earth, which contributes 
 immeasurably the greater part of the action, but to the heavy 
 body, which contributes but an infinitesimal part. When we 
 have discovered that a man's death is due to the action upon 
 him that we call typhoid fever, we know the cause of his 
 death ; and this cause was known long before the agent, the 
 micro-organism, was discovered. When we find a window 
 starred, we have no doubt that the starring is due to the impact 
 of a hard body, though we may be quite unable to discover 
 the body, the agent w^hose action was the cause of the 
 damage. 
 
 An action is sometimes mistaken for an agent. Natural 
 Selection, which is the action upon living organisms of 
 destructive agents, is often spoken of as an agent, and taken 
 to be an agent. Few expressions are more frequent in the 
 writings of biologists than ' the action of Natural Selection ', 
 an expression that is quite correct if it means * the action that 
 is called Natural Selection ', but that is mistaken if it means, as 
 it often does, * the action that is produced by Natural Selec- 
 tion.' Passing this error, which is something more than an 
 error in nomenclature, we come to the first of the errors 
 enumerated in our list, the taking of an agent for a cause. 
 This is a very common error in popular speech. * Thou art 
 the cause of this anguish, my mother.' ' You are the cause 
 of this disaster.' Mill even considered the earth to be the 
 cause of the fall of a stone. It is, of course, the action of the 
 mother, and of the other person accused, and of the earth, that 
 were the causes. The persons w^ere the agents, and not being 
 actions, could not be causes. I think every one with a nice 
 sense of the use of language, and of the meanings of words, will 
 admit that to speak of a person, or indeed of any other agent, 
 as a cause, is a perversion of language. 
 
ISO 
 
 ON CAUSATION. 
 
 (2) In the search for causes we are not obliged to go back as 
 far as the agent. The cause is already discovered when we 
 have discovered the action connected with the change or 
 unchange in the thing acted on ; but it is often extremely 
 useful to identify the agent, and some of our investigations 
 mto causation, such as those into the causation of crimes, have 
 no other purpose. Still, as we have seen, the action and the 
 agent are often identified, and very often indeed no sufficient 
 distmction is drawn between them, and search is made for an 
 agent instead of for an action. Nay, the fancied necessity for 
 finding an agent is so urgent, that not only may that be taken 
 for an agent which exerts no action on the thing changed or 
 unchanged, but also an agent that is purely imaginary may be 
 invented ad hoc, and the cause may be identified, not only 
 with an agent that is no agent for the purpose in view, but 
 even with an agent that does not exist. 
 
 The attribution of causation to agents that have no existence 
 except in the im.agination of the searchers after cause appears 
 a priori unlikely, but in experience it is frequent enough. 
 Gardeners attribute canker in fruit trees to the action of 
 sourness in the subsoil on the roots of the trees, but there is 
 neither proof nor evidence that the subsoil is sour. I have 
 myself tested the soil three feet below a badly cankered fruit 
 tree, and found no acid reaction ; but this is, I am pretty 
 sure, the only attempt that has ever been made to test the 
 subsoil for sourness. The spiritualistic medium accounts for 
 the table rapping out a wrong answer, by the existence of a 
 lying spirit in the table ; but there is no proof and no evidence 
 that the spirit of the medium has entered into the table. The 
 Mendelian accounts for feeble-mindedness in other people by 
 the transmission of a unit-character from the parents of the 
 feeble-minded ; but there is no proof and no evidence of the 
 existence of a unit-character in either parents or child. Perhaps ' 
 the most remarkable and the least justifiable of these imaginary 
 agents is that of the psycho-analyst. He assumes that the 
 cause of your forgetting a word is some unpleasant association 
 of the word in your mind. In fact, in most cases there is 
 no evidence of any such unpleasant association ; but the psycho- 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 151 
 
 analyst, like the spirit rapper, is equal to the occasion. He 
 says the very fact, that you cannot remember any unpleasant 
 experience connected with the word, is itself proof that you 
 have had such an experience; for, being unpleasant, you have 
 thrust it out of your mind. The less you remember it, in 
 fact, the more certain it is that you are wilfully putting it out 
 of your mind, and the more you wilfully put it out of your mind, 
 the more certain it is that the remembrance is unpleasant. In 
 short, the less evidence there is that you have had such an 
 experience, the more certain it is that you must have had it. 
 Deny that you have wilfully put out of your mind either the 
 word you have forgotten or its unpleasant association, and still 
 the psycho-analyst is ready for you. Your will was exercised 
 unconsciously. "' Manifestly, by such means as this one could 
 prove anything. What cannot be accounted for by uncon- 
 scious volition is accounted for by repressed sexual passion, the 
 existence of which is assumed with a similar disregard of the 
 necessity of evidence. It is another imaginary agent. It would 
 be tedious to enumerate but a tithe of the imaginary agents that 
 have been invoked as causes of phenomena. They range from 
 the sour subsoil of the gardener, through the repressed com- 
 plexes of the psycho-analyst, the Social Contract of Rousseau, 
 and the arch^us of Paracelsus, to the hypostatised Ideas of 
 
 Plato. 
 
 The imaginary agent invoked as a cause was the causa non 
 
 vera of the Scholastic writers. 
 
 (3) Next in gravity of error to imagining an agent that is 
 ^ imaginary is to take for a cause an action that is imaginary. 
 Though not quite so grave or so gratuitous a blunder as the 
 last, this is bad enough, and it is extremely frequent. It is 
 the error that underlies judicial astrology, and the greater part 
 of the bewildering lore of amulets, mascots, omens, talismans, 
 phylacteries, and lucky and unlucky things of all descriptions 
 Astrologists declared, yes, and still declare, for there are still 
 survivors of this queer class of believers, that the position of the 
 planets at the moment of a man's birth determines the whole 
 course of the subsequent life of the ' native.' The planets do 
 
152 
 
 ON CAUSATION. 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 I5J 
 
 really exist. They are not mere phantoms of the imagination,, 
 like the lying spirit of the table or the unconscious pain of the 
 psycho-analyst ; and having a real existence, they are agents, 
 in some respects and towards some things. They act, for 
 instance, on their satellites, and on one another. But there is 
 not a smidgeon of evidence that they act upon the course of 
 human lives in the way the astrologers imagine. Similarly, 
 charms and amulets, and the whole apparatus of popular 
 superstitions, do exist as material objects ; and having a real 
 existence, they are capable of action of some sort, if only by 
 their weight ; but there is no evidence that they exert the 
 action that is attributed to them by popular fancy. 
 
 It is common to find that people who go to warmer, 
 damper, and more low-lying places sleep more and are less 
 energetic than they were when at home ; and it is common 
 to find that people who go to colder, higher, and drier places 
 appear to gain energy and to be capable of m.ore exertion. 
 These effects are always attributed to the action of the air in 
 such places, which is said to be * relaxing ' in the one case, 
 and * bracing' in the other. There is no evidence that the 
 air has any such action, or that there is any difference in the 
 air of the one place and the air of the other. Not seldom 
 places of the two different qualities are near together, and the 
 wind frequently blows from the relaxing place to the bracing 
 place, and vice versa. It is most improbable therefore that the 
 air in the one place is appreciably different from the air in the 
 other ; and if a difference were found, it would still remain to 
 be proved, by one of the twelve methods set forth in the last 
 chapter, that this difference has or can have such an action 
 on the human body as is attributed to it: 
 
 Many temporary and obscure ailments are attributed, not 
 only by the laity, but by some medical practitioners, to * a 
 sluggish action of the liver,' or to * a chill on the liver.' The 
 actions of the liver are many, and are imperfectly known, but 
 in the cases in question there is not a shadow of evidence that 
 any one of them is being performed less actively than usual,., 
 nor is there any evidence that the liver has been chilled. The 
 liver is deeply seated, and is covered by thick layers of muscle^ 
 
 bone, skin, and other structures, and could not possibly be 
 chilled unless the temperature of the whole body were reduced ; 
 and if it were, there is no evidence whatever that such lowering 
 of the temperature of the liver could produce the effects that 
 are attributed to it. Many drugs are advertised and taken for 
 the purpose of purifying or cooling the blood ; but apart from 
 the want of evidence that the blood of the person taking them 
 is impure, or is unduly hot, there is no evidence whatever that 
 these drugs exert any purifying or cooling action upon it. 
 
 Gardeners and rustics commonly attribute changes in the 
 weather to changes in the moon, which are really changes in 
 the relative positions of moon, earth, and sun ; but that these 
 relative positions have any influence upon the weather there is 
 no evidence to show. 
 
 At a certain spiritualistic seance at which Dr. (now Sir James) 
 Crichton Browne was present, ' manifestations ' occurred until 
 he so plugged the eyes and ears of the medium that the medium 
 could neither see nor hear; then the manifestations ceased. 
 At the end of the sitting, a believer who was present attributed 
 the cessation of the manifestations to ' the offensive incredulity 
 of Dr. Crichton Browne.' There was no evidence, however, 
 that this mental attitude of the sceptic exerted any action upon 
 the medium, or upon the spooks who were supposed to be in« 
 relation with the medium ; while there was another action of 
 Sir James' upon the medium to which the effect might wxU 
 
 have been attributed. 
 
 When the Hawke rammed the Olympic in the Solent, those 
 
 ^on board the Olympic attributed the change in the course of 
 
 the Hawke to the action of starboarding her helm ; but it was 
 
 proved at the trial that this action was imaginary : the Hawke 
 
 had not starboarded her helm. 
 
 The mistake of attributing as a cause an action that is entirely 
 imaginary is as old as humanity, and shows little sign of be- 
 coming less frequent, although the most impressive exposure of 
 it that has ever been made is three thousand years old. It is to be 
 found in the Wisdom of Solomon, xiii, ii, and runs as follows :— 
 
 * Now a carpenter that felleth timber, after he hath sawn 
 down a tree meet for the purpose, and taken off all the bark 
 
154 
 
 ON CAUSATION. 
 
 skilfully round about, and hath wrought it handsomely, and 
 made a vessel thereof fit for the service of man's life ; 
 
 'And after spending the refuse of his work to dress his meat; 
 hath filled himself; 
 
 ' And taking the very refuse among those which served to no 
 use, being a crooked piece of wood, and full of knots, and hath 
 carved it diligently when he had nothing else to do, and formed 
 it by the skill of his understanding, and fashioned it to the image 
 of a man ; 
 
 ' Or made it like some vile beast, laying it over with ver- 
 milion, and with paint colouring it red, and covering every spot 
 therein ; 
 
 * And when he had made a convenient room for it, set it in a 
 wall, and made it fast with iron ; 
 
 ' For he provided for it that it might not fall, knowing that 
 it was unable to help itself ; for it is an image, and hath need 
 of help ; 
 
 *Then maketh he prayer for his goods, for his wife and chil- 
 dren, and is not ashamed to speak to that which hath no life. 
 
 ' For health he calleth upon that which is weak; for life he 
 prayeth to that which is dead ; for aid humbly beseecheth that 
 v/hich hath least means to help ; and for a good journey prayeth 
 of that which cannot set a foot forward ; 
 
 * And for gaining and getting, and for good success of his 
 hands, asketh ability to do of him that is most unable to do 
 anything. 
 
 * Again, one preparing himself to sail, and about to pass 
 through the raging waves, calleth upon a piece of wood more 
 rotten than the vessel that carrieth him.' 
 
 No doubt it will startle the ecclesiastically minded ladies who 
 throw some of the spilt salt over their shoulders to avoid 
 disaster, to know that their attitude of mind is the same as that 
 of the idolater. 
 
 (4) The action attributed as a cause may not be on the thing 
 in which the effect is produced. 
 
 This is the fundamental error of witchcraft, of spells and 
 charms, and many other superstitions. Witches undoubtedly 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 15s 
 
 existed : the agent was not imaginary. Nor was the action 
 imaginary, for the witches did undoubtedly exercise their craft. 
 They did cast spells and execute incantations, they did say the 
 Lord's prayer backwards, they did make wax figures, and stick 
 pins in them, and exercise in other ways the craft of the witch ; 
 and these things they did in order to influence the weather, to 
 produce illness and misfortunes to their neighbours, to make 
 their cattle slip their calves, their children have fits, and to 
 cause other effects. But the gap in the chain of causation was 
 that the action they exercised was not upon the thing they 
 desired to change. Whatever incantations they uttered exer- 
 cised no action on the weather. The pins which would have 
 produced pain and injury if they had been stuck into the persons 
 of the witches' enemies, were not stuck into their persons ; they 
 were stuck into images of them. The action was not on the 
 thing in which the effect was to be produced. The spells that 
 they cast upon the cattle or the children did not act upon the 
 cattle or the children ; and if any effects on the various objects 
 followed the witchcraft, they could not have been due to the 
 witchcraft, which did not act on the things in which the effects 
 were produced. 
 
 It is currently believed that if you cut your nails on a Friday, 
 or bring a peacock's feather into the house, or cross the knives, 
 or spill the salt, or view the new moon through glass, or do 
 any of a hundred other harmless acts, the action will bring 
 misfortune upon you. In each of these cases there is an action; 
 but in none of them is the action upon the thing in which any 
 . unfortunate effect that may follow is produced. You cut your 
 nails on Friday, and on Sunday you put a sovereign instead 
 of a shilling into the offertory. The misfortune happens right 
 enough, but the action was on the nails, not on the sovereign. 
 You bring a peacock's feather into the house, and in the follow- 
 ing week your child at school is attacked by measles ; but your 
 action was on the feather, not on the child. You spill the salt, 
 and next day your horse casts a shoe, or your motor tyre bursts 
 at an inconvenient moment ; but your action was on the salt 
 and the tablecloth, not on the horseshoe or the tyre. 
 
 A certain Irish tenant tried to diminish what he considered 
 
156 
 
 ON CAUSATION. 
 
 his landlord's rapacity by shooting the landlord's agent ; but 
 the action, strenuous though it was, was not directed at the 
 thing, the landlord, that the tenant desired to alter, and was- 
 therefore ineffectual ; and so the landlord explained. * If you 
 think ' said he * that you can intimidate me by shooting my 
 agent, you are very much mistaken.' 
 
 An old woman who had the reputation of a witch acquired a 
 large practice by uttering a certain spell, to which immense 
 efficacy was attributed by her neighbours, who willingly paid 
 her for it the fee that she demanded, which consisted of a loaf 
 and a penny. At length her practices reached the ears of the 
 authorities, who seized her and threatened to tie her thumbs 
 and great toes together, and to duck her in the horse-pond, 
 secundum artem, unless she revealed the spell by which the 
 wonders were worked. I trust I do them no injustice if I 
 surmise that the authorities would not have been unwilling to 
 have in their own hands an instrument of such power. Under 
 this duress the poor woman consented to reveal the text of her 
 spell, which ran, so she said, as follows : — 
 
 Thy loaf in my lap, 
 
 Thy penny in my purse ; 
 Thou art never the better, 
 
 And I am never the worse. 
 
 It seems unlikely that the action of uttering this could have 
 had the causal influence with which it was credited, and the 
 same may be said of all spells and incantations, whether of 
 witches or of psycho-analysts. 
 
 (5) The action on the thing changed may have no connection 
 with the change. 
 
 To attribute an effect to an action with which it has no con- 
 nection is a blunder, and a very frequent blunder, but it is a 
 much more pardonable blunder than any that we have con- 
 sidered hitherto. As we have seen in the seasonal variations in 
 the frequency of suicide, it may be impossible to trace the nature 
 of the connection, even when the facts render a connection of 
 some kind certain ; and experience of such cases might well. 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 157 
 
 lead us to suppose a connection when the nature of the con- 
 nection is obscure. But the error we are now examining does 
 not rest on experience of such cases, and does not consist m 
 inferring a connection that is obscure : it consists in inferring 
 a connection without sufficient evidence. The seasonal varia- 
 tion of suicides, the concurrent variations of sunspots and 
 magnetic storms, and many other instances, show that to 
 establish a connection it is by no means necessary to discover 
 the nature of the connection ; but it is necessary to establish, 
 by one of the twelve methods described in the previous 
 Chapter, that there is a connection, or causation cannot properly 
 
 be inferred. 
 
 It is evident that the fallacy in all the previous cases that 
 have been examined lies in the absence of any connection 
 between an action and the change or unchange in the thing 
 acted on. Such a connection is necessarily absent when the 
 supposed action is that of an imaginary agent, such as acid in 
 the subsoil, or unconscious pain, or a Social Contract ; or is 
 itself imaginary, such as the supposed action of the planets on 
 human life, or that of a chill on the liver ; nor can there be a 
 connection between an action and an effect if the action is on 
 something other than that in which the effect is produced, as 
 when witches stick pins into the effigy of a person they desire 
 to bewitch, or a tenant shoots the agent in order to affect the 
 landlord ; in all these the connection is wanting, but is not the 
 only thing that is wanting. There remain still other cases in 
 which an agent that actually does exist, exerts a real action 
 upon the thing on which the effect is produced, and yet we are 
 ^ not justified in regarding it as a case of causation, for want of 
 evidence, such as is required by the Methods described in the 
 last Chapter, of connection between the action on the thing 
 ;and the effect produced in that thing. In these cases, since so 
 many more of the conditions of causation are satisfied, and the 
 last link only is wanting, the error is less enormous, and may 
 easily be committed by those who have sense enough to avoid 
 the greater errors; while, on the other hand, those whose 
 menUl equipment is insufficient to save them from the greater 
 i>lunders are scarcely likely to avoid the less. 
 
158 
 
 ON CAUSATIOxN. 
 
 The opportunities for committing the error now under con- 
 sideration are perhaps greater in medical practice than in any 
 other range of observation. When a drug is administered to 
 a person who is ill, and thereafter the symptoms change for 
 better or for worse, it is difficult not to assume that the admini- 
 stration of the drug was the cause of the change, especially 
 if the change is in the direction of improvement. In such a 
 case all the gross errors are eliminated. The agent, the drug 
 does exist; it does exert action; its action is upon the thing' 
 the body of the patient, that changes ; and moreover the action 
 definitely precedes the change. All these conditions are satis- 
 fied, but we are still in doubt, or ought to be in doubt, whether 
 the action of the drug was the cause of the change in the 
 symptoms ; for connection between the action and the chancre 
 is not established. '^ 
 
 There is a widespread notion, dating from the battle of 
 Waterloo, that the firing of heavy guns is a cause of rain. 
 The firing of heavy guns does produce an action, and a powerful 
 action of its kind, upon the thing, the atmosphere, in which 
 a change occurs when it begins to rain ; but no connection 
 has been shown between the cause and the effect. At the 
 battle of Waterloo, and no doubt many times before and since 
 that battle, there was an association between the cause and the 
 effect : but in the first place, the alleged cause did not precede 
 the effect, for it had rained heavily for several days before ; 
 and in the second place it has never been shown, A, that the 
 action was isolated— that it was the only action upon the 
 atmosphere at that time— ; nor, B, that the association is con- 
 stant— that the firing of heavy guns is always followed by rain—; 
 nor, C, that it is followed by rain more frequentlv than casual 
 association would account for; nor, D, that there is any pecu- 
 liarity in the rain that falls after the firing of heavy guns, 
 that is constantly present in such rain, and absent from other 
 rain. We may therefore confidently assert that the firing of 
 heavy guns has not been proved to be a cause of rain. 
 
 The fallacy of arguing /^os^ hoc, ergo propter hoc is so frequent 
 and so well recognised that further illustrations are not needed, 
 but what is needful is to point out, what never has been pointed 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 159 
 
 out, viz. : why it is a fallacy when it is fallacious. For it is not 
 always fallacious. Quite the contrary. In every case in which 
 a cause acts and produces a change, the effect follows the 
 cause, and is both post hoc and propter hoc ; and in those cases 
 in which the effect imm.ediately follows the cause we argue 
 propter hoc because of the immediacy />os^ hoc, and on no other 
 ground. It is only when an interval of time elapses between 
 the action and the effect that there is opportunity for fallacy 
 to enter into the reasoning ; and whenever the interval is short, 
 the fallacy is extremely alluring and extremely frequent. Never- 
 theless, it has been recognised as a fallacy for two thousand 
 years, and yet, in the face of this common knowledge, Hume 
 and Mill, and all their followers down to the present hour, have 
 taught that causation is nothing but sequence— invariable 
 sequence it is true, but still, invariable sequence and no more. 
 
 What constitutes the argument post hoc, ergo propter hoc a 
 fallacy when it is fallacious, is, of course, the absence of any 
 proof of connection between the action that is ante and the 
 effect that is post. This is the element that must be added 
 to mere sequence in order to transform it into causal sequence ; 
 and this is the element that Hume perversely denied, and that 
 Mill and all his followers have failed to appreciate, although 
 in every case of causation that they witnessed throughout life 
 it must have jumped at them and hit them in the face. When 
 the sequence is instant and immediate, we argue connection 
 from sequence alone : in other cases it must be proved by one 
 of the methods set forth in the last Chapter, on the Methods 
 of Ascertaining Causes, for each of these methods is a method 
 of establishing connection between action and effect. Until a 
 connection is established, that which is post can never safely be 
 assumed to be propter : as soon as the connection is estab- 
 lished, causation is proved. Of course, if causation were mere 
 sequence, or invariable sequence, or unconditional sequence, 
 whatever that may mean, the argument post hoc, ergo propter 
 hoc would not be fallacious; but the very same writers who 
 declare that causation is nothing but sequence insist in another 
 chapter that to argue from post hoc to propter hoc is a notorious 
 fallacy. 
 
■i6o ON CAUSATION. 
 
 (6) The action may not precede the effect if it is a change, 
 •or be contemporaneous with it if it is an unchange. 
 
 Of all the errors in attributing causation this is the most 
 difficult to avoid, and the most pardonable when it is incurred. 
 In some cases it is so difficult to determine precedence that 
 the only justifiable course is to suspend our judgement; but 
 this course, always difficult, seems to be most difficult in 
 attributing causation. In many cases the action, which is 
 the cause, arises so gradually that it is difficult to fix its 
 position in time ; and the change also that it effects may 
 be spread over a considerable duration, so that the cause and 
 the effect are for part of their duration contemporaneous, even 
 when the effect is a change. When the effect is an unchange, 
 contemporaneousness may be difficult to establish ; and when 
 the effect as well as the cause is an action, as it sometimes is 
 in the case of an unchange, cause and effect are reciprocal, and 
 which is to be called cause, and which is to be called effect, 
 depend on the way in which they are contemplated. 
 
 Was his excessive drinking the cause of his insanity ? 
 Granted that the proper association is established, so that 
 we may be sure there is a causal connection between the 
 drinking and the insanity, then the answer to this question 
 depends on which came first. If the drinking preceded the 
 insanity by months or years, that settles the question ; but 
 supposing that he did drink heavily for a short time before 
 the insanity was recognised, is it certain that the insanity was 
 recognised as soon as it existed ? One of the earliest symptoms 
 of insanity is defect of self-control, and defect of self-control 
 is a condition that favours excessive drinking. Insanity in 
 the early stage is often difficult to detect, and to be sure of. 
 Is it not possible then, that the excessive drinking was rather 
 .an early symptom than a cause of the insanity ? 
 
 A certain game becomes popular, and about the same time 
 a book upon it is published. It is said that the publication 
 of the book is the cause of the game becoming popular, but 
 may it not be the other way about ? A book is not often 
 published unless there is a public to which it appeals, and 
 the existence of such a public is just the thing to stimulate 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 I6l 
 
 an enterprising publisher. In such a case we must ask which 
 came first, but this cannot be determined with certainty. The 
 date of publication of the book can, indeed, be determined 
 with accuracy, but how are we to determine when the game 
 became popular? Attaining popularity is a gradual process, 
 and may spread over months or years. In such a case we 
 must suspend our judgement pending further information, and 
 it may be that the matter cannot be determined. 
 
 Increase of population has been said to be a cause of taking 
 inferior and hitherto uncultivated land into cultivation ; and 
 reversely, the taking of such land into cultivation has been 
 said to be the cause of increase in the population. Which is 
 correct ? It seems that the only way to determine is to 
 discover which was first ; but by the nature of the case this 
 cannot be discovered, for both are slow and gradual processes, 
 having no definite time of beginning. 
 
 Is the failure in the flow of the sap the cause of the death 
 of the leaves in autumn ? or is the death of the leaves the 
 cause of the failure of the sap to rise ? or are they not common 
 effects of some other cause ? In this case again, the causal 
 connection is established ; but again it is quite impossible to 
 say whether the slackening of the sap-flow precedes the begin- 
 ning of the death of the leaves first to die, or whether the 
 gradual death of the leaves precedes the gradual failure of the 
 sap-flow. But in this case we can call experiment to our aid. 
 We can ring the tree, and so stop the flow of sap ; and then 
 Ave find that the leaves do in fact die, but they die in a very 
 different manner, and the tree dies too. Or we may strip 
 the tree of leaves and see if the sap ceases to flow ; and when 
 the experiment is tried, we find that the sap does not cease to 
 flow, for the naked branches bud again. In this case, there- 
 fore, we may confidently assert that the death of the leaves 
 and the failure of the sap-flow are common effects of some 
 other cause. 
 
 Is the formation of the heavy rain-drops of a thunderstorm 
 the cause or the effect of the electrical disturbance ? If we 
 could tell which change preceded the other we should have no 
 doubt ; but this we cannot tell. 
 
 II 
 
 m 
 
 vm 
 
 h 
 
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 Ki.\ 
 
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l62 
 
 ON CAUSATION. 
 
 Syphilis is said to have been introduced into Europe in- 
 April, 1494, by Pedro Boyle and Pedro de Margarit, the first 
 a Benedictine monk and the second a Calabrian gentleman, 
 both of whom accompanied Bartholomew Columbus, the 
 brother of Christopher, in his voyage to and from New His- 
 paniola. On the other hand it is alleged that the disease had 
 long existed in Europe, and even that Egyptian mummies 
 have been found with the signs of the disease upon them. 
 If the latter assertion is true, the former is a false attribution 
 of causation. 
 
 It appears from the foregoing considerations that even when 
 we employ our nine or twelve canons for ascertaining causation, 
 we cannot always be successful ; and when we can successfully 
 establish a causal connection between two events, we cannot 
 always determine which is cause and which is effect, or whether 
 both may not be effects of some third action. 
 
 (7) The last error in attributing causation is that a condition 
 may be mistaken for a cause. 
 
 This is a blunder that is very commonly made : it is perhaps 
 the most frequent of all the blunders that are made in assigning 
 causes ; and fortunately it is the least important. If we discover 
 that a certain percentage of potash in the soil is necessary to 
 obtaining the maximum crop of potatoes, it does not greatly 
 matter, from one point of view, whether we speak of the. 
 application to the soil of so much potash as the cause of a 
 bumper crop, or of the presence in the soil of the potash as 
 the cause ; though of course the latter, as a passive state, is 
 a condition, not a cause, of the crop being a bumper crop. 
 On the other hand, to call a man's sex, or age, or the locality 
 or climate in which he lives, a cause of his disease, is clearly 
 a misnomer, and shows a confusion of mind : and it can never 
 be as important, with reference to the causation of his disease, 
 to discover his age or sex as to discover that which acted, 
 on him. 
 
 Though a condition is not a cause, and though the difference 
 between condition and cause is often conspicuous and important,, 
 yet there are many cases in which the distinction is not impor- 
 tant, and many in which it is quite as important to discover 
 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 163 
 
 the conditions of an effect as to discover its causes. The 
 external causes of the growth of plants are few, and are 
 ascertained. They are the action of warmth and light upon 
 the plant ; but the conditions under which a given plant will 
 thrive are often extremely difficult to ascertain. There are 
 certain plants that seem to be animated by feminine caprice. 
 Side by side in the same garden, in the same soil, in the same 
 aspect, subject, as far as we can discover, to the same con- 
 ditions in every ascertainable respect, one plant of tropceoliim 
 speciostim will thrive luxuriantly, and another will dwindle and 
 perish. The sciences of agriculture and horticulture consist 
 almost wholly in the study of conditions. Obviously, a passive 
 state is by its very nature less conspicuous than an action, and 
 therefore the discovery of a condition is almost necessarily 
 more difficult than the discovery of a cause. 
 
 It is often as important to discover a condition as to discover 
 a cause, and for this among other reasons, that the discovery 
 of a condition often points to a cause, or enables us to eliminate 
 an action or an agent that we have thought of as causally con- 
 cerned. The researches of Wells into the cause of dew con- 
 sisted in identifying one after another the conditions under 
 which dew is deposited, and those which interfere to prevent 
 its deposition ; and when these were ascertained they pointed 
 straight to the causal action, namely refrigeration of the stratum 
 of moist air in contact with the bedewed surface, the only 
 action common to all the conditions. One of the conditions 
 of the occurrence of a strong wind is a low pressure of air, 
 as indicated by a low barometer ; and this points straight 
 to the cause — the action of the pressure of the air in a neigh- 
 bouring region of higher pressure. A motor-car runs better 
 after it has been running for some time, and again the con- 
 dition points to the cause ; for the only action that has taken 
 place in the interval has been the action of the engine and 
 moving parts on themselves and each other, and this action, 
 whatever other effect it may have had, must have had the 
 effect of warming up the engine and other moving parts ; and 
 it can be shown a priori that warming them up is likely to 
 improve the running of the car. 
 
 
 4 
 
 I ^!: 
 
 f ■ 
 
1 64 ON CAUSATION. 
 
 On the other hand, the discovery of a condition may assist 
 us in eliminating an action or an agent that we have thought 
 of as possibly having a causal connection with the effect. 
 A man is suspected of having committed a certain burglary, 
 but it is found that one of the conditions of the burglary, the 
 window through which the burglar is known to have entered, 
 is incompatible with this man's action, for it is too small for 
 him to get through. It is surmised that sourness in the subsoil 
 is the agent that causes canker in fruit trees ; but one of the 
 conditions in which the tree grows is the presence of chalk 
 in the subsoil, and chalk is incompatible with sourness. It is 
 suspected that the ship was lost in obedience to the orders of 
 the owners, that they might claim the insurance money ; but 
 it is discovered that the ship was under insured. 
 
 Again it is often important to discover a condition for its own 
 sake. The cause may be well known, but the conditions under 
 which it acts may be obscure, and in that case it is important 
 to discover the governing conditions ; and these are the cases 
 in which it is usual to call the enabling condition the cause. 
 No harm is done in practice by the confusion of nomenclature, 
 but still, the confusion is there, and accurate thought expressed 
 in accurate language would clear it up. It is, however, as 
 prevalent in books on logic as among plumber's labourers. 
 We speak of the absence of a damp-proof course in the walls 
 of a room as the cause of the room being damp. Strictly 
 speaking the effect is not the room being damp, but the room 
 becoming damp ; and the cause of this is the action of the 
 moisture from the soil, creeping, by capillar}^ attraction and 
 other forces, up the walls. One condition of this penetration 
 of moisture into the wall is the absence of a damp-proof course ; 
 and so we speak of the absence of this course as a cause of the 
 room being damp. It is not a cause. The absence of a thing 
 cannot possibly be a cause. It is a condition. If there were 
 a damp-proof course in the wall, the moisture could not pene- 
 trate that course, and could not rise above it ; and the wall not 
 becoming damp, the room would not become damp. Still, for 
 practical purposes we call the absence of the course the cause, 
 because we know now what prevention to apply, and where to 
 
 ERRORS IN ATTRIBUTING CAUSATION. 
 
 I65 
 
 apply it. What is the cause of the oven not getting hot ? 
 The cook will tell you it is the door or the window being open ; 
 but these are passive states, and therefore conditions, and not 
 causes. The cause is the action of the draught of cold air ; 
 and this is not caused, but permitted, by the door or the window 
 being open. If she said that the opening of the door or of the 
 window was the cause of the oven being refractory, she would 
 be punctually correct, for this, though not the proximate cause, 
 was the cause of the proximate cause, and therefore a cause of 
 the effect. A cause is an action, and an effect is a change or 
 unchange. But when the result of an action upon a thing is 
 to produce a change, the changed state or result may be a 
 condition of further change in that or other things. In the 
 instances just given, the confusion of cause with condition is 
 not important for the purpose of the cook, or of the builder who 
 is called in to remedy the dampness of the room, but it is 
 important for the logician who is discussing the nature and 
 relations of cause and effect, and the rules for discovering them. 
 The importance of the distinction appears very plainly in the 
 indescribable muddle that, for lack of it, appears in the books 
 that discuss these subjects, omnes libros canentes eandem 
 cantilenam, as Van Helmont says. 
 
 Summary. 
 
 In order to prove causation it is necessary to prove 
 
 (i) Action on the thing on which the effect is produced. 
 
 (2) Precedence of the action on the change, or accompaniment 
 of the action with the unchange. 
 ^ (3) Connection between the action and the effect. 
 
 In thus endeavouring to prove causation, the following 
 blunders are committed : — 
 
 (i) An agent may be taken for an action. 
 
 (2) The agent may be imaginary. 
 
 (3) The action may be imaginary. 
 
 (4) The action may be real, but not on the thing changed or 
 
 unchanged. 
 
 (5) The action may be on the thing, but unconnected with the 
 
 effect. 
 
 ■41 
 
 * '-I 
 
 
w enw - : i- ' ^» * wae' *T'wtt ' ."-«-g 
 
 166 
 
 ON CAUSATION. 
 
 (6) The action may not precede the change or accompany 
 the unchange. 
 
 (7) A condition may be taken for a cause. 
 
 The first blunder is frequent, but not often very important. 
 The second is the worst of all, and is not made except by the 
 most muddleheaded. The next is nearly as bad, and the rest 
 decrease in importance in succession until the last is often 
 practically unimportant, though it is one which a clear thinker 
 would never make. 
 
 CHAPTER VIII. 
 
 f 
 
 CAUSES OF DEATH. CAUSES OF INSANITY. 
 
 How great is the need of clear and correct concepts of cause 
 ■and effect, and how great, too, the need of a knowledge of the 
 proper methods of ascertaining and assigning them, is well 
 shown by the official publications on the causes of death and 
 of insanity. The Registrar General and the Board of Control 
 annually publish elaborate Tables, from which it is evident that 
 neither of these authorities has any clear notion of what is 
 meant by a cause, or of the means that should be adopted to 
 verify causation. Both authorities publish as causes what are 
 not causes, and both authorities have altered from time to time 
 the construction of their Tables without improving materially 
 their illogical character. The Board of Control, the successor 
 of the Lunacy Commission, has followed its dignified prede- 
 cessor in frankly abandoning the attempt to distinguish causes 
 of insanity, not only from its conditions, but even from its 
 accompaniments. This seems to me a deplorable admission of 
 incompetence. The old Table, that did at least purport and 
 pretend to be a Table of Causes, is now superseded and 
 replaced by a Table of ^Etiological Factors and Associated 
 Conditions. 'iEtiological Factors ' would not be a bad term if 
 it were intended to embrace causes, direct and indirect, imme- 
 diate and remote, as well as conditions. It is a sound, logical, 
 .comprehensive term, which might properly be employed to 
 include all these things ; but I am sure that I do no injustice 
 to the Committee of the Medico-Psychological Association 
 which drew up the Table and gave to it its title, when I say they 
 
 H 
 
 I'. 
 
i68 
 
 ON CAUSATION. 
 
 had no such meaning and no such intention. There is not 
 the least doubt that their reason for giving to the Table this 
 new title was to seek in vagueness a refuge from uncertainty. 
 They did not know what constitutes a cause, nor did they know 
 the rules or methods by which causes should be assigned ; and 
 small blame to them, for philosophers could not tell them, and 
 if they knew, which is improbable, of the various definitions of 
 cause given in the books, they had the good sense to disregard 
 them. They collected a hotch-potch, whose constituents they 
 were unable to discriminate from one another, and they selected 
 a title that is a dignified name for a hotch-potch. If it is 
 objected, as it well may be, that many of the items in the 
 Table are not Causes nor Etiological Factors, they can reply 
 that at any rate they are Associated Conditions, and thus 
 silence that criticism. It is true that they lay themselves open 
 to the much more damaging criticism that such a hotch-potch 
 is of no conceivable use to any human being ; but this, perhaps, 
 they did not foresee. 
 
 I. Causes of Death. 
 
 The Registrar General divides causes of death into Primary 
 causes and Secondary causes ; and it is significant of the 
 validity of the distinction that at different times he has defined 
 them in different ways. Originally, in 1845, the instruction of 
 the Registrar General was : ' Write the causes of death in the 
 order of their appearance, and not in the presumed order of 
 their importance.' As he did not mean primary and secondary, 
 that is to say, first and second in order of importance, it is a 
 pity that he used these terms ; and as he meant first and 
 second in the order of time, it is a pity that he did not use 
 terms, like first and second, or earlier and later, which would 
 have expressed accurately what he did mean. However, some 
 of the medical practitioners to whom the forms were issued 
 persisted in assuming that the Registrar General meant what 
 he said, and accordingly returned as primary cause of death 
 that which they considered more important, and as secondary 
 that which they considered less important. As this practice 
 grew and increased, the statistics naturally lost in value, and 
 
 CAUSES OF DEATH. 
 
 169 
 
 became much confused, so that it might have been supposed 
 that the Registrar General, who recognised and deplored the 
 confusion, would have revised either his formula or his instruc- 
 tions. In fact he did neither. He allowed the terms to remain, 
 and withdrew his instructions altogether, leaving the certifiers 
 to interpret his terms as they pleased. This happened in 1902, 
 and for the next nine years medical men who certified causes 
 of death were left to their own discretion, to interpret primary 
 and secondary as they pleased. The result, which is creditable 
 to the doctors, was that most of them interpreted the terms 
 in their proper sense, as first and second in the order of 
 importance. 
 
 In 1893, a Select Committee reported on the subject, and 
 advised that if the terms primary and secondary were retained, 
 they should be defined * as meaning the order of the develop- 
 ment of the diseases as they occurred,' that is to say that the 
 Registrar General should revert to the former vicious practice of 
 defining the terms in a sense that is false, and that they cannot 
 properly bear. The Registrar General did not take this advice. 
 As I have said, he withdrew the instructions, and left the doctors 
 to do as they pleased ; and then, after a decent interval of nine 
 years, he directed that the primary cause of death was to be con- 
 sidered ' that cause of death which was of greatest importance 
 and upon which any other related causes were dependent.' 
 
 It is unfortunate that the Registrar General, following the 
 example of Mill, whose teaching has so long been dominant in 
 the matter of causation, is not able to make up his mind about 
 the meaning of his terms,, and gives several definitions, which 
 are not only unsatisfactor}', but are inconsistent with each other, 
 and even with themselves. In his Suggestions to Medical 
 Practitioners, he defines primary cause of death (in the case of 
 deaths from disease) as 'the disease, present at the time of 
 death, which initiated the train of events leading thereto, and 
 not a mere secondary, contributory, or immediate cause, or a 
 terminal condition or mode of death.' In a footnote he adds :. 
 * Acute specific diseases, if of recent occurrence, are to be con- 
 sidered the primary cause of death, even though the actual 
 disease, as tested by the power of infection, be no longer 
 
 it 
 
 Ma 
 
 
IJO 
 
 ON CAUSATION. 
 
 present at the time of death.' Thus he warns us that his 
 cardinal test of what is primary may be no test at all. He 
 takes back with one hand what he has just given with the other, 
 and leaves us in confusion. If we turn to the remainder of the 
 definition for guidance we are no better off, for it does not help 
 us much to understand what is meant by a primary cause of 
 death to be told that it is not a mere secondary cause. But 
 even in this he is not consistent, for though this contradictory 
 footnote appears in his Suggestions, it is not embodied in the 
 instructions to medical practitioners that appear on the face of 
 the certificate of death. ' Secondary cause ' he does not attempt 
 to define, though he warns us that a terminal condition or 
 mode of death should not be entered as a secondary (or con- 
 tributory) cause ; but as he does not tell us what he means by 
 a terminal condition or mode of death, this does not give us 
 much assistance ; and if he did, it would only tell us what a 
 secondary cause is not : it would not tell us what it is. 
 
 In most ordinary cases of causation a cause is a cause ; that 
 is to say, it is one of a train of causes, and if it is omitted, if 
 the train is broken at any point, the effect will not be produced. 
 If the cat does not begin to eat the rat, or if the rat does not 
 begin to gnaw the rope, or if the rope does not begin to hang 
 the butcher, the rest of the effects will not be produced, and the 
 old woman will never get home. The case of death, however, 
 is peculiar. The death of every human being is inevitable, and 
 the utmost that any cause of death can do is to hasten or 
 precipitate a result that must take place some day. For 
 practical purposes, however, we look upon the duration of life 
 as indefinite, and call that a cause of death which is the cause 
 that death, which otherwise would have been postponed, occurs 
 at a particular time. In other words, the cause of death is that 
 which hastens or precipitates an event that would in any case 
 have occurred sooner or later. Now it is evident that the 
 extent or degree to which life is shortened by any cause 
 materially affects our estimation of the cause. If a man is 
 already so ill that his life is despaired of, and he may die any 
 hour, we scarcely regard as a serious or important * cause of 
 death ' the dose of morphia that not only relieves his pain. 
 
 CAUSES OF DEATH. 
 
 171 
 
 but overpowers his enfeebled respiratory centre, and accelerates 
 his death by a few hours at most. We should not in such a 
 case enter poisoning by morphia as a cause of death. On the 
 other hand, if a young man in robust health, whose expectation 
 of life is thirty or forty years, were to die with symptoms of 
 narcosis after a large dose of morphia, we should unhesitatingly 
 enter, as the cause of his death, poisoning by morphia. 
 
 We may look upon the living animal as a clock, wound up 
 at conception to go for a certain maximum time. When death 
 occurs, the clock stops ; but, apart from disease and accident, 
 the clock will not stop until it runs down — until the spring has 
 unwound itself and its resilience is exhausted. When this 
 happens, the clock must stop. For the first years of life the 
 spring has double work to do. It has not only to keep the clock 
 going, but also to build it up in bulk and complexity. When 
 this task slackens and ceases, the whole energy of the spring is 
 devoted to keeping life going, and therefore early adulthood is 
 the time of greatest vigour, and the time when the attacks of 
 disease are most easily repelled. As the tension of the un- 
 winding spring diminishes, less and less serious interference 
 suffices to stop the clock. When it is fully wound, the power 
 of the spring will drive the clock even though the pivots are 
 lubricated with cart-grease ; when it is nearly run down, a slight 
 thickening of the oil on a frosty night will arrest the action. 
 So it is with human life. In early adulthood, the motive power 
 is abundant, and it takes much interference to stop the clock of 
 life ; but as age advances, the power of living weakens and 
 fails, until at length in extreme old age, which is to be 
 measured not by years only, but rather by the amount remain- 
 ing of the initial store of energy, a very trifling obstruction, an 
 obstruction so trifling that we cannot identify it, is enough to 
 be a ' cause of death.' It may be in some cases, such as that 
 of the first Duke of Wellington, that the clock merely runs 
 down, and there is no more to be said. The Registrar General 
 deprecates the return of old age as a cause of death, but in 
 5uch a case as that of the Iron Duke it is difficult to see what 
 more accurate return could be made. 
 
 Properly considered, life is what I have called an unchange. 
 
 f 1'' 
 
 1 m 
 
172 
 
 ON CAUSATION. 
 
 It is the maintenance of a continuous state in spite of opposing 
 forces which tend to terminate it. A cause of death is an 
 action that removes one or more of the conditions maintaining 
 the unchange, and allows it to be brought to an end. Life is 
 maintained with effort and with striving, and subject to certain 
 conditions. Any interference with any of these conditions 
 increases the difficulty of maintaining life ; interference with a 
 second condition, or further interference with the same con- 
 dition, further increases the difficulty ; and the concurrence of 
 two or more interferences may increase the difficulty to the 
 point of impossibility. In this way there may be several 
 causes simultaneously tending to bring life to an end, and it 
 may be very difficult in a given case to say hov/ much of the 
 effect is due to one cause, and how much to another. The effect 
 is death, and it is incongruous to speak of part of death being 
 produced by one cause and part by another ; nor is it much 
 less incongruous to speak of death as being partly due to one 
 cause and partly to another. In such a case it is the combina- 
 tion of causes that produced death, and if this is so, and if 
 neither of the causes acting singly would have produced it as 
 and when it happened, can we rightly say that one was a more 
 important cause than the other ? Which is the more important 
 cause of the discharge of a gun — the loading of it, or the pulling 
 of the trigger? This case is scarcely on all fours, however, 
 with the case of death. If one cause would have produced 
 death sooner or later, and the cooperation of a second caused 
 the death to take place sooner, then I think the former may be 
 considered the more important, the less the anticipation pro- 
 duced by the latter. 
 
 The cause of death is always a function of two variables — 
 the power acting to maintain the unchange that we call life, 
 and the action or actions that increase the work that the 
 power has to do. To recur to the simile of the clock, the time 
 of death depends on the amount of resilience left in the spring 
 and the amount of friction in the works that must be over- 
 come. If this friction is materially increased at more than one 
 place in the train, then each increase is a separate cause of the 
 stopping of the clock. The less the power or means of living. 
 
 I 
 
 •i 
 
 CAUSES OF DEATH. 
 
 ^73 
 
 the less interference with the processes of life necessary to 
 bring life to an end ; the greater the life-worthiness, the more 
 powerful must be the interference necessary to cause death. 
 
 Again, the living body may be likened, and the likeness is 
 more than a mere simile, to a besieged fortress. It is con- 
 stantly subject to the assaults of microscopic enemies, who are 
 trying to obtain a footing, but are repelled as long as the 
 garrison is strong enough. If the fortress is attacked by a 
 single foe strong enough to break down its defences and 
 capture it, then the action of that foe singly is the cause of the 
 fall of the fortress. But it may be that while engaged in 
 repelling one invader, which is not strong enough alone to 
 capture it, the fortress is attacked by another, and the com- 
 bined assault succeeds. In such a case the cause of the 
 capture is the combination of assaults. Or it may be that 
 the garrison is completely successful in repelling one assailant, 
 but at such a cost that it falls a prey to a second, of perhaps 
 inferior power, which succeeds in consequence of the exhaustion 
 of the defenders. In such a case the second attack was the 
 cause of the capitulation, but the exhaustion left by the first 
 was a necessary condition. 
 
 If we use the term Cause, with a capital, to include both 
 cause and condition, and cause, with lower case, to mean a true 
 cause or action as distinguished from a condition, then I think 
 the Causes that may combine to produce the death of any 
 individual man may be combined in any of the four following 
 ways : — 
 
 Case I. The first Cause is a cause of the second ; or, other- 
 wise put, death is due to some particular manifestation of a 
 disease, which, without that manifestation, might or might not 
 have been fatal. A man suffers from typhoid fever, from 
 which he might recover, but that the fever causes a perforation 
 of the bowel, which kills him. He might recover from his 
 rheumatism, but for endocarditis which is a manifestation of 
 the rheumatism. He might recover from his endocarditis, but 
 for an embolism which is caused by the endocarditis. He 
 suffers from phthisis, which might endure for years but for an 
 haemoptysis, which is rapidly fatal. He suffers from diabetes. 
 
 i^i 
 
174 
 
 ON CAUSATION. 
 
 and the diabetes causes coma, which ends in death. He suffers- 
 from general paralysis, and dies in status epilepticus, which is a 
 manifestation of the general paralysis. 
 
 The fatal manifestation of a disease is, I surmise, what the 
 Registrar General means by a terminal condition or mode of 
 death ; but as he gives no indication whatever as to what he 
 does mean, this can be no more than a surmise. In such cases 
 the disease may appropriately be called the Principal cause of 
 death, and the manifestation the Precipitating or Subordinate 
 
 cause of death. 
 
 Case II. The first Cause is not the cause, but is a necessary 
 condition of the second. It is necessary in the sense that 
 without it the cause could not have come into operation. A 
 person suffers from a compound fracture, which becomes 
 complicated with pyaemia, of which he dies. The fracture 
 is not the cause of the pysemia. The cause of this is infection 
 with the appropriate coccus ; nevertheless, this infection would 
 never have taken place but for the existence of the compound 
 fracture, regarded as a continuing passive state — as a condition. 
 It is not the occurrence or action of the fracture that produces 
 the infection, and therefore the fracture is not the cause of the 
 infection ; but without the existence of the fracture the 
 infection could not have occurred. The fracture is a necessary 
 condition of the pysemia which is the cause of death. Or a 
 man suffers a chill, which so diminishes his powers of resist- 
 ance that the pneumococci, that before were harmlessly present 
 in his body, are now able to make an effectual attack, to invade 
 his lungs, and to cause pneumonia, of which he dies. Regarded 
 as an action on the body, and it is quite legitimate so to regard 
 it, the chill is a cause of death ; but it is not the cause of the 
 pneumonia. The cause of the pneumonia is the invasion of 
 the pneumococcus, and of this invasion the chill was a necessary 
 condition. But when we regard the chill as a condition, we 
 do not regard it as an action ; we regard it as a passive state ; 
 and as a passive state it is a necessary condition of the attack 
 of pneumonia, for without the existence of the chilled state of 
 the body the infection of the pneumococcus would not have 
 taken place. The chill by itself was not the cause of death. 
 
 »: 
 
 CAUSES OF DEATH. 
 
 17? 
 
 Death would not have occurred from the chill without the aid 
 of the coccus. The pneumonia was the cause of death, but 
 without the chill there would have been no pneumonia. 
 
 In such cases we may call the necessary condition the 
 Preparatory cause of death, and the subsequent cause the- 
 Consummating cause of death. 
 
 Case III. The first Cause is a favouring, but not a necessary 
 condition of the second. Persons who are already suffering 
 from measles or typhoid fever are more obnoxious to the 
 attack of broncho-pneumonia than those not so suffering ; and 
 broncho-pneumonia is more likely to be fatal to those who are 
 already suffering from measles or typhoid fever than to those 
 who are not. Yet measles and typhoid are neither of them a 
 necessary condition of the pneumonia. They are not necessary 
 either in the sense that pneumonia necessarily follows them, or 
 in the sense that one of them must necessarily precede pneu- 
 monia in general. Nevertheless, it may be that in any 
 particular case the precession is necessary, and that without it 
 the pneumonia would not have occurred, or would not have 
 been fatal. Still, since it is impossible to say that broncho- 
 pneumonia cannot occur unless it is preceded' by measles or 
 typhoid, we cannot say that the specific fever is a necessary 
 condition of the broncho-pneumonia. Persons suffering from 
 diabetes are specially liable to be attacked by phthisis. 
 Diabetes is no necessary condition of phthisis, either in the 
 sense that diabetes is necessarily followed by phthisis, or 
 that phthisis is necessarily preceded by diabetes ; but the 
 frequency with which diabetics are attacked by phthisis 
 indicates that the existence of diabetes favours the occurrence 
 of phthisis. 
 
 In this case again the condition may be called a Preparatory 
 cause, and the subsequent disease the Consummating cause of 
 death. 
 
 Case IV. The last case is that in which two causes, neither 
 of which is in any way dependent on the other, combine to 
 bring about a death that neither of them singly might have 
 been able to produce. A man is suffering from heart disease, 
 which does not menace his life as long as the heart is not 
 
 yy 
 
 la 
 
 \ 
 
i 
 
 176 
 
 ON CAUSATION. 
 
 I li 
 
 I 
 
 subjected to extraordinary strain. He is attacked by bron- 
 chitis, which would not be fatal if his heart were sound ; but 
 the effect of the bronchitis is to put a strain upon the heart 
 that, in its damaged condition, the heart is unable to overcome ; 
 and the combination of diseases is fatal. Or he suffers from 
 ague, which by itself might leave him years of life, but that 
 he is attacked by dysentery, which alone would not be fatal, and 
 the combination of the two diseases carries him off. 
 
 In such cases one of the two diseases may be found to play 
 a preponderant part in bringing about the fatal issue. In the 
 first of the two instances given above, the heart disease may be 
 regarded as preponderating, and in the second the dysentery. 
 Thus viewed the causes may be called Preponderant and 
 Adjuvant ; but it is not easy in any case, and in many cases 
 it is not possible, to assign to either of the diseases a prepon- 
 derant part ; and if it is not practicable, then we can only fall 
 back upon the order in time, and speak of the causes as Earlier 
 and Later. 
 
 There are here three pairs of terms that may be used to 
 characterise, in appropriate cases, the several causes of death. 
 They may be characterised as 
 
 Principal and Precipitating or Subordinate, 
 Preparatory and Consummating, 
 Preponderant and Adjuvant, or Earlier and Later. 
 If I am right in my surmise that what I have called a 
 Precipitating or Subordinate cause of death is what the 
 Registrar General means by a terminal condition or mode of 
 death, then, as he advises the certifier not to insert the terminal 
 condition or mode of death into the certificate, this cause is 
 ruled out, and in cases in which the causes of death can be 
 distinguished as principal and subordinate, the principal cause 
 only should appear in the certificate. I should have thought 
 that it would be of value to know the number and proportion 
 of cases in which the precipitating cause of death in typhoid 
 fever, for instance, is perforation, those in which it is haemor- 
 rhage, those in which it is hyperpyrexia, those in which it is 
 exhaustion, and so forth ; but no doubt the Registrar General 
 knows best. 
 
 I 
 
 ;; i\ 
 
 m 
 
 CAUSES OF DEATH. 
 
 177 
 
 Excluding the pair just dealt with, in the very great majority 
 of deaths in which more than one cause can be assigned, the 
 causes are related in the way I have explained as Preparatory 
 and Consummating, or as condition and cause. Most people, 
 I think, would understand the term ' condition ' in the sense 
 in which it is here used, as a pre-existing state, either 
 necessary or helpful to the occurrence of the fatal disease ; and 
 the term Preparatory cause would, I think, be allowed to be a 
 substitute for condition, accurate enough for ordinary use. The 
 term Consummating cause would perhaps scarcely be as readily 
 accepted, but once accepted and become familiar, it would not 
 give rise to difficulty. I do not think there is any other term 
 that expresses the nature of the cause, and its relation to the 
 preparatory cause or condition, with the same accuracy. Im- 
 mediate cause is ambiguous, and might easily be misleading. 
 It would be very apt to be confused with what I have called 
 the Subordinate or Precipitating cause of death. The terms 
 Primary and Secondary have been found in the experience of 
 many years to be misleading and confusing, and I think they 
 would be better abandoned ; but if they are to be retained, then 
 I think it should be explained that in these classes of cases, 
 Primary means Preparatory, and Secondary means Consum- 
 mating, in the senses here explained. 
 
 When the causes of death are two independent diseases, 
 the difficulty is greatest. If it were possible always, or even 
 frequently, to decide which of them took the greater share in 
 bringing about the death, it would undoubtedly be better to 
 ' distinguish them as Preponderant and Adjuvant ; but this is 
 unfortunately not often possible. The alternative is to distin- 
 guish them by the order in time of their occurrence, as Earlier 
 and Later ; but this distinction is ruled out by the instructions 
 of the Registrar General that are now in force. In a consider- 
 able proportion of cases in which two diseases that appear to 
 be independent co-operate to bring about death, we may sus- 
 pect that the earlier in time does in fact facilitate the attack of 
 the later, and therefore many cases that appear prima facie to 
 belong to Class IV may be removed into Class III without 
 doing violence to the facts ; but when the case unmistakeably 
 
 12 
 
 
 m 
 
 
 I; 
 

 u 
 
 178 
 
 ON CAUSATION. 
 
 belongs to Class IV, and it is not possible to apportion the 
 degrees of importance among the causes, I do not see how the 
 terms Primary and Secondary can be made applicable except 
 by taking them to mean first and second, which would not only 
 be contrary to the instructions of the Registrar General, but 
 would introduce inexcusable ambiguity and confusion into the 
 meaning of the terms. It seems that there is no single sense 
 in which the terms Primar>' and Secondary can be used that 
 will cover all the cases of the relation between two causes of 
 death when more than one cause has been in operation ; nor is- 
 there any other pair of terms that can be used for the same 
 purpose, for the relation is not the same in all cases. 
 
 In the tabulation of causes of death, one cause only is 
 entered, and the Registrar selects for this purpose that cause 
 which is ' most important ' out of the two or more that are 
 submitted to him by the certifier. Now, it seems from the 
 language used by the Registrar General, and from the whole 
 trend of his remarks, that he looks upon the ' importance ' of a 
 cause of death as in the first place an ascertainable quality, 
 and in the second place a fixed quality, a quality that is 
 present or absent, and if present at all, present in some fixed 
 degree which does not vary. This, however, is not so. The 
 importance of anything varies with the point of view from 
 which we regard it. Regarded from the point of view of the 
 hostess of a garden party, or of the farmer whose hay is cut 
 but not carted, the state of the weather is of great importance ; 
 regarded from the point of view of the cook, who spends her 
 life in the basement, or the prisoner, who spends his life 
 under cover, the state of the weather is of no importance at 
 all. The cause of death which is important to the doctor who 
 has an hypothesis to test may be of no importance at all to 
 the police ; and the cause of death which is important to the 
 police may not have any importance at all to the company in 
 which the life of the deceased was insured. Before we can say 
 that a cause of death is important or unimportant, or estimate 
 the degree of its importance, we must settle the point of view 
 from which the importance is to be regarded. It is more im- 
 portant, says the Registrar General, that this death, which was. 
 
 CAUSES OF DEATH. 
 
 179 
 
 caused by the combination of measles and bronchitis, should 
 be registered as death from measles than as death from bron- 
 chitis ; but why ? From the point of view of the doctor who 
 has views about bronchitis it may be very much more impor- 
 tant that bronchitis was a cause of death than that measles 
 was a cause of death. If the Registrar General considers that 
 measles is a more important cause than bronchitis, it can only 
 be because for some purpose it seems more important 
 to ascertain the number of deaths in which measles had a share 
 than to ascertain the number in which bronchitis had a share. 
 It is impossible, therefore, to estimate the relative importance 
 of the different causes of death in any given case for the purpose 
 of registration, until we know what this purpose is ; and as to 
 the purpose of compiling tables of the causes of death, the 
 Registrar General does not enlighten us. I do not know for 
 certain what this purpose is. I do not even know whether 
 the Registrar General has any one purpose distinctly and 
 prominently before his mind, and I strongly suspect that he 
 has more than one purpose, but does not distinctly formulate 
 to himself what his purposes are. It is clear, I think, that 
 it is impossible to estimate with any approach to accuracy the 
 relative importance of different causes of death until we know 
 for what purpose the information is required, and in what 
 respect importance is to be estimated ; and i{ more than one 
 purpose is to be served by the estimation, it must often happen 
 that more than one estimate of the relative importance must be 
 made. It is clear that no single set of Tables could be com- 
 piled from both points of view ; and if more than one purpose 
 is to be served by compiling these Tables, the purposes should 
 be clearly before the mind of the compiler, and each purpose 
 should have a separate set of Tables to itself. The suggestion 
 may be a counsel of perfection, and very likely tlie Registrar 
 General would say that it is impracticable ; and with the funds 
 and the staff at his disposal it may be so ; but what I have 
 said is true for all that. Relative importance cannot be gauged 
 until purpose is settled ; and causes, rightly selected for their 
 importance for one purpose, will be wrongly selected if used for 
 another purpose ; and whatever the purpose of the Registrar 
 
 I'vfl 
 
 1 
 
 
i8o 
 
 ON CAUSATION. 
 
 |.ii 
 
 General in selecting this or that cause of death, he should have 
 it clearly before his mind, and he should stick to it. 
 
 II. Causes of Insanity. 
 
 Among the Tables of Statistics issued by the Board of Control 
 is a Table of the ^Etiological Factors and Associated Condi- 
 tions of Insanity. The former Table, now superseded, spoke 
 frankly of Causes of insanity, but this term is now replaced by 
 /Etiological Factors, which is more vague and more cautious. 
 The table is as follows : 
 
 Heredity. 
 Insane 
 Epileptic 
 Neurotic 
 Eccentricity 
 Alcoholism 
 Mental Instability, as revealed by 
 Moral Deficiency 
 Congenital Mental Deficiency 
 
 not amounting to insanity 
 Eccentricity 
 Deprivation of Special Sense 
 Smell and Taste 
 Hearing 
 Sight 
 Critical Periods , 
 
 Puberty and Adolescence 
 Climacteric 
 Senility 
 Child-bearing 
 Pregnancy 
 
 Puerperal State (non septic) 
 Lactation 
 Mental Stress 
 Sudden 
 Prolonged 
 
 Toxic 
 
 Alcohol 
 
 Drug habit 
 
 Lead and other such poisons 
 
 Tuberculosis 
 
 Influenza 
 
 Puerperal sepsis 
 
 Other Specific Fevers 
 
 Syphilis, acquired 
 
 Syphilis, congenital 
 
 Other toxins 
 Traumatic 
 
 Injuries 
 
 Operations 
 
 Sunstroke 
 Diseases of the Nervous System 
 
 Lesions of Brain 
 „ „ Spinal Cord 
 
 Epilepsy 
 
 Other Definite Neuroses (limited 
 to Hysteria, Neurasthenia, 
 Spasmodic Asthma, Chorea). 
 
 Other Neuroses which occurred 
 in infancy (limited to convul- 
 sions and night terrors). 
 
 CAUSES OF INSANITY. 
 
 I8l 
 
 Physiological Defects and Errors 
 Malnutrition in early life 
 Privation and Starvation 
 Over-exertion, physical 
 Masturbation 
 Sexual Excess 
 
 Other Bodily Affections 
 Haemopoietic System 
 Cardio-vascular Degeneration 
 Valvular Heart Disease 
 Respiratory System and Tuber- 
 culosis ^ 
 Gastro-intestinal System 
 Renal and Vesical System 
 Generative System, excluding 
 
 Syphilis 
 Other general affections not 
 above included 
 
 ( The Committee that drew up this Table was cautious, but it 
 was not clear. The Table previously in force was headed and 
 called a Table of the Causes of Insanity ; and a queer hotch- 
 potch it was, in which overwork appeared in one place, and 
 over-exertion in another, and a previous attack was entered as 
 a cause of the existing attack of insanity. I had pointed 
 out that several of the ' causes ' enumerated in that Table were 
 not causes, and could not be causes of anything, and it may 
 have been my protest which induced the Committee to sub- 
 stitute for the term Causes the term iEtiological Factors. The 
 old legal maxim says that fraud lurks in generalities, and to the 
 uncritical it often seems that safety lies in generalities. Certain 
 It is that refuge in generalities is a great saving of thought, 
 and appears a great safeguard against criticism. Any criticism 
 of any item in the Table, based on the ground that it is not a 
 
 . cause, may be met by the defence that it is an Etiological 
 Factor, or at any rate an Associated Condition ; and of course 
 it would be difficult to show, if it existed at all, that it was 
 not one or the other. The manoeuvre, adroit as it is, has the 
 defect, frequent in such manoeuvres, of being too clever by half. 
 It is true that it eludes criticism of the items in the Table, but 
 at the cost of transferring the criticism to the Table as a whole. 
 W^hat is the use of a Table which includes both Etiological 
 Factors and Associated Conditions, and, it may be added, other 
 things as well, and does not distinguish the one class from the 
 other ? 
 
 "B; 
 
 / 11 
 
 r iM 
 
X 
 
 I 
 
 182 
 
 ON CAUSATION. 
 
 Some of the items in the Table are neither Etiological 
 Factors nor Associated Conditions. Mental Instability, for 
 instance, may be sufficiently great to amount to insanity, but 
 then it is the insanity, at least it is so in the eyes of the com- 
 pilers of the Table, to whom insanity means disorder of mind. 
 Mental Instability can no more be an ^Etiological Factor of 
 insanity, or an Associated Condition of insanity, than a move- 
 ment of the air can be an Etiological Factor of wind, or an 
 Associated Condition of wind ; or than sunshine can be an 
 Etiological Factor of light, or an Associated Condition of 
 light. The movement of the air is the same thing as wind : 
 the sunshine is the same thing as light : and the Mental 
 Instability is, at any rate in the eyes of the compilers, the same 
 thing as insanity. It is in truth a part of insanity. 
 
 ^ Again, there are many items in the Table that are not of the 
 slightest value there, and that make one wonder what' on earth 
 they were included for. I conjecture that the Committee was 
 nervous lest anything should be omitted, and therefore put in 
 everything its members could think of. Defect of smell and 
 taste are, no doubt, conditions that may be associated with 
 insanity, and so are baldness and tight boots, a Roman nose 
 and a fondness for pickles ; and it is about as useful to know 
 that any one of these is associated with insanity as any of the 
 others. The last two clauses include, or may include, every 
 disease to which humanity is subject, and I can conceive that 
 it may in certain connections be useful to know whether any 
 particular disease is particularly frequent or infrequent among 
 mad people ; but I cannot conceive that a disease that may 
 affect a person years before or years after he becomes mad, can 
 have any rightful place in a Table of Etiological Factors of 
 insanity. To mix up with Etiological Factors of insanity con- 
 ditions that are manifestly only accidentally associated with it 
 seems to me to go out of the way and undertake a laborious 
 task in order to introduce confusion, and destroy what useful- 
 ness the Table might otherwise have had. 
 
 The influence of Heredity in the causation of Insanity seems 
 to me misconceived, or rather perhaps unconceived, in spite of 
 the explanation that I gave a quarter of a century ago, an 
 
 CAUSES OF INSANITY. 
 
 183 
 
 explanation which has never been even examined or criticised 
 by any subsequent writer, although it carries a fundamental 
 revolution in the concept of the causation of insanity. Insanity 
 is the breakdown of the human machinery ; and when a 
 machine becomes unable to do its work, the reasons cannot be 
 anything but the original construction of the machine and the 
 strains or stresses that it has had to bear. The strains or 
 stresses that it has to bear are actions upon the thing, the 
 human machine or organism, in which the change or effect of 
 insanity is produced ; and are therefore rightly called causes ; 
 but the constitution of the machine, the way in which it is put 
 together, the stability of its construction, is not an action. It 
 is a passive state ; and at the utmost cannot be more than a 
 condition. Indeed it almost requires a stretch of language to 
 call it a condition. The man is the thing on which the action 
 takes place and on which the effect is produced ; and the man 
 is the result of his heredity, that is to say of the mixture of 
 the qualities of his ancestors. This mixture is, therefore, at the 
 utmost the cause of a condition, which means an indirect cause. 
 By the study of the patient's heredity, that is to say of the 
 qualities of his parents and ancestors, we can make a very 
 rough guess at the nature of the thing, the man, upon which a 
 cause acts so as to produce the result insanity, and that is the 
 utmost that a study of heredity can give us. 
 
 The causes of insanity, properly so called, are the actions 
 brought to bear upon the man which produce in him the 
 change from sanity to insanity, and the result of insanity.^ For 
 . the purpose of the argument, the man is summarised in his 
 brain ; and actions that produce insanity are actions on^ the 
 brain, which may most conveniently be divided into the direct 
 actions of physical agents, the indirect actions of physiological 
 processes, such as child-bearing, and the still more indirect 
 action of emotion-producing situations of the man in the world 
 around him. This is the natural grouping and classification 
 of the strains or stresses that produce insanity ; but for some 
 reasons known only to themselves, writers on insanity refuse to 
 adopt it. I do not know what their reasons are, but I surmise 
 that one reason is that the classification is a clear, useful, and 
 
 I 
 
r 
 
 If 
 
 h 
 
 184 
 
 ON CAUSATION. 
 
 scientific classification, and the other is that it is proposed by me, 
 who am not a German. Had it been proposed by a German, it 
 would have been adopted with acclamation long ago, but no 
 German would be capable of discovering a classification so 
 clear and logical. 
 
 However, taking the list— it cannot be called a classifica- 
 tion—proposed by the compilers of this table, it will be 
 interesting to inquire into the grounds for the supposition that 
 the alleged causes, or aetiological factors, are in fact causes. 
 
 Heredity has already been examined. The next group. 
 Mental Instability, includes no cause of insanity, and nothing 
 that by the utmost stretch of the meaning of words can be 
 called a cause of insanity, or of anything else ; for nothing in 
 the group is an action. The same may be said of the third 
 group. Deprivation, by which is evidently meant not depriva- 
 tion,^ but absence, of a special sense, is not an action : it is a 
 passive state ; and I know of no evidence that, as a passive 
 state, the absence of a special sense is material to the result 
 of insanity ; and if not, then it cannot be even a condition. 
 
 The next group is composed of critical periods of life ; and 
 these come in the class of physiological strains or stresses that 
 may be causes of insanity, because they undoubtedly are, or 
 may produce, actions on the brain. But what evidence is there 
 that these do in fact exert such action on the brain as may 
 disorder its mode of working, and so produce the change from 
 sanity to insanity ? Many people, the great majority of people, 
 who go through these physiological crises do not become insane 
 Many people become insane at other times than at the times of 
 these crises. On what ground, then, are they regarded as causes 
 of insanity, and what is the justification for so regarding them ? 
 These are questions which no writer on insanity has ever 
 answered, or ever asked, or ever considered ; but they are 
 questions that demand an answer, for until they are satisfac- 
 torily answered, the writers have no business to assume that 
 these crises are causes at all ; and the same may be said of all' 
 the other alleged causes of insanity. Does the belief that these 
 alleged causes are causes of insanity rest upon the application 
 of Mill's Canons, or of any of them ? It certainly does not. No 
 
 ./ 
 
 CAUSES OF INSANITY. 
 
 185 
 
 one has ever yet discovered, or ever will discover, two or more 
 cases of insanity that have nothing in common but the circum- 
 stance that the patient was going through one of these crises. 
 No one has ever discovered, or ever will discover, an instance 
 in which insanity occurs, and an instance in which it does 
 not occur, which have every circumstance in common except 
 adolescence or senility. No one has ever discovered, or ever 
 will discover, two or more instances of insanity having only 
 adolescence and senility in common, and two or more instances 
 of sanity that have nothing in common but the absence of 
 adolescence or senility ; and no one, as far as I know, has ever 
 wasted time in an unprofitable search after such impossible 
 instances. Yet there is a general consensus that these and 
 other physiological crises are causes, or at least occasions, of 
 insanity, a consensus not merely of opinion, but of deep-rooted 
 conviction. What is the justification for the belief ? It is to 
 be found in those methods of assigning causes that I have 
 grouped together under the heading of Association. It is 
 found in experience that these physiological crises are asso- 
 ciated as antecedents with insanity, not in isolation, not con- 
 stantly, but either more frequently than casual concurrence 
 will account for, or, when associated, the insanity has some 
 peculiar feature which does not occur in other cases of insanity, 
 not so associated. In other words, the causal connection is 
 ascertained by the Method IV. C, or IV. D. ; and the same 
 methods are employed in almost every case in which causes 
 are assigned for the occurrence of insanity ; but not in every 
 case. 
 
 In the insanity that is due to drunkenness, and in that which 
 follows immediately or rapidly upon the absorption of other 
 drugs, the first Method, that of Instant Sequence, which in 
 these cases becomes Rapid Sequence, is employed, together 
 with Method IV. A, Association in Isolation. The effect follows 
 rapidly after the action, and so raises a presumption that it is 
 due to the action. The action is isolated : it takes place in 
 circumstances which enable us to say with considerable confi- 
 dence that no other material action has occurred ; and this 
 confirms the presumption. Further, in many cases the associa- 
 
 \'^ 
 
[I 
 
 r 
 
 1 86 
 
 ON CAUSATION. 
 
 tion is, in the same person, constant ; whenever he takes the 
 alcohol or other drug, the insanity of intoxication constantly 
 follows : when he does not take it, the insanity does not occur. 
 But suppose the association is not constant, or that no oppor- 
 tunity of observing constancy has occurred ? Suppose that an 
 excess of alcohol has been taken only once, and that insanity 
 has occurred only once, and then following the drink ? Then 
 the Method of Common Rarity is applicable, and is applied. 
 In other cases it is found that a little drink is followed by but 
 slight indications of insanity, and that the more drink is taken 
 the more complete and profound the insanity becomes. In such 
 cases the Method of Concurrent and Proportional Variation 
 confirms our conviction. Commonly, too, the insanity that 
 follows drinking has peculiar qualities that are present in 
 other cases of such insanity, and are not present when insanity 
 is not preceded by drinking ; and the Method of Association 
 D becomes applicable. In short, whenever causation is rightly 
 assigned, it is assigned by the application of one or more 
 of the twelve Methods here described ; and never by any of 
 the Methods prescribed in Mill's Canons. 
 
 Summary. 
 
 Causes of Death. 
 
 The instructions of the Registrar General require us to 
 distinguish primary from secondary causes of death, but give 
 us no clear guidance what is to be considered primary and 
 what secondary. 
 
 Death is inevitable, and its causes are inherent in human 
 nature. That which we call the cause of death in any 
 individual case is the cause of death happening at the particular 
 time and in the particular way it does. Life is an unchange, 
 and death the cessation of the unchange. 
 
 When more than one cause co-operate to produce death, the 
 causes may be combined in one of four ways. 
 
 I. The first cause may be a cause of the second. 
 
 CAUSES OF INSANITY. 
 
 187 
 
 II. The first cause may be a necessary condition of the 
 second. 
 
 III. The first cause may be a favouring condition of the 
 
 second. 
 
 IV. The several causes may be independent. 
 
 In the first case the causes may be called Principal and 
 Subordinate, or Principal and Precipitating ; in the second 
 case, Preparatory and Consummating ; in the third. Pre- 
 ponderant and Adjuvant ; and in the fourth, Earlier and 
 Later. 
 
 The first three pairs may all be included under Primary 
 and Secondary. The last pair cannot be so included. 
 
 The relative importance of different causes of the same 
 death must depend on the purpose the observer has in view. 
 
 Causes of Insanity. 
 
 The Table issued by the Board of Control rightly does not 
 pretend to be a Table of Causes exclusively ; but to mix up 
 causes, conditions, and associated states in the same Table 
 deprives the Table of any value whatever for any purpose ; 
 and some of the headings in the Table are neither causes, 
 conditions, nor associates of insanity. 
 
 By following the rules laid down in Chapter VI., it might 
 be possible to identify many causes of insanity, and to avoid 
 the useless confusion of the Table. 
 
 \' 
 
I 
 
 
 f 
 
 h 
 
 i 
 
 CHAPTER IX. 
 
 ON BELIEF. 
 
 Every philosophical discussion, and most of other discus- 
 sions, are discussions about the meaning of words, either of 
 single words, or of phrases, or of propositions ; and most 
 philosophical discussions, and many others, are barren and 
 inconclusive because the different disputants, and often the 
 same disputant, attach different meanings to the same word, 
 phrase, or proposition, and often attach to it no clear meaning 
 at all. In order to use a word, or a phrase, or a proposition, 
 correctly and with propriety, it is by no means necessary that the 
 user should be able to formulate in other words what his 
 meaning is. The ability to feel and appreciate nice shades of 
 meaning, and to express them in appropriate words, long 
 precedes the ability either to define the distinctions or to 
 formulate the meaning. The difference between ' I shall ' and 
 ' I will ' is felt by every Englishman, though by no Irishman 
 or Scot ; but not one in ten thousand of those who use these 
 expressions correctly, and never confuse them, could formulate 
 in words the difference of meaning. It is the same with the 
 great majority of words and expressions in common use. We 
 feel their meanings : we always use them correctly ; but if we 
 are asked to define them in other words, not one of us in ten 
 thousand could do so satisfactorily. 
 
 In common use, and on common occasions, the want of 
 formal definitions of the words we employ does not matter 
 much, for we understand each other, and ourselves, sufficiently 
 
 ON BELIEF. 
 
 189 
 
 ^ell for common purposes ; but discussions, and especially 
 Is us^Ls upon mauers that have puzzled mankmd for ages 
 a equite futiL unless we fix beforehand, as accurately as we 
 cln the meaning of the words and phrases upon wh.ch the 
 d scussi^n hingel In common use, the -^^ Jehef and 
 Believe have many different meanmgs. As used m he 
 Catechism-' All this I steadfastly believe '-and m the 
 Cr eds o'the Christian Church, the phrase ' I believe ' means 
 iZ convinced,' 'I accept that statement as an assertion of 
 fact In current use, as when We say ' I believe he ,s gone 
 out,-- it means uncertainty It means not ' I -.-"-""J. - 
 is Jone out,' or ' It is a fact that he is gone out, but I think 
 lergone out, but I am not sure.' Again, Belief may mean, 
 not only at one time, as in the first example, assured conviction 
 and at another time, as in the second example, doubt inclining 
 o affirration, but it may be used, as I ^^^ -f '^^^^^^ l^e 
 of this chapter, as a generic term, to mean at one and the same 
 le ver^'d gree and shade of belief, from axiomatic certainty 
 through approximate certainty, and every degree of increasing 
 doubt to utter disbelief and inconceivability. In this sense the 
 name Belief has many meanings, all, however, referring to 
 laTes of m nd or attitudes of mind. Attitudes of mind towards 
 whatV Towards fact, most people would say, and the answer 
 :' d be approximately true, but fact is not the only thing o 
 which we attune our beliefs, and if it were, and as far as it is. 
 we must know precisely what we mean by tact. 
 
 b'S Truth Doubt, Certainty, Opinion, Possibility, Credi- 
 bilS P;obability. and many more, are all words germane to 
 tWs discussion, and if we scrutinise them with care, we shall 
 se that they fall naturally into three classes. Some of them 
 we can predicate of ourselves, but not of impersonal thing .VVe 
 can sav I doubt, I believe. I think, I am of opinion ; but we 
 ca^not'^say It d;ubts, it believes, it thinks, or it is of opinion 
 Other we can predicate of impersonal things, but not of 
 SirselL- We 'an say It is true, it is probable, ,t is credible^^ 
 or possible, or likely; but we cannot say I ^- * d'set "f 
 t^robable I am credible, or possible, or likely. A third set ot 
 Trds which are but few. we use indifferently either way. We 
 
 1 
 
 1 
 
 i i^ 
 
 ! i 
 
r 
 
 190 
 
 ON CAUSATION. 
 
 can say I am certain, and It is certain ; I am doubtful, and It 
 is doubtful. In these cases, however, we are conscious of a 
 certain impropriety in one of the uses. * I am doubtful ' means 
 no more and no less than 4 doubt,' and the latter, as the shorter 
 and more direct expression, is the one that ought to be preferred. 
 * I am certain ' means no more and no less than ' I know ' ; and 
 might be discarded in favour of I know. Discarding the words- 
 of this mixed and intermediate class, there remain those which 
 we predicate of ourselves, and which indicate states of our 
 minds, and those which we predicate not of ourselves, but of 
 impersonal things. The question arises To what kind of things 
 do words of the second class refer ? What is in apposition to 
 the ' It ' which is the subject of the proposition ? 
 
 About this there is no room for doubt : ' It ' refers to a 
 
 statement. It is true that , or probable that , or credible 
 
 that . In every case the predication refers to a statement ; 
 
 but in every case an attitude of mind is implied, and in every 
 case the statement is a statement of fact : so that in every 
 case of the kind there are three things to consider and investi- 
 gate : the fact, the statement about the fact, and the attitude 
 of mind towards this statement. These three factors may at 
 once be reduced to two. When we express the attitude of our 
 minds towards a statement of fact, we are adopting an indirect 
 method of expressing an attitude towards the fact itself This 
 is clearly shown by those cases in which we use the same word 
 towards both. * I am certain that hens lay eggs ' indicates our 
 attitude of mind towards a fact. * It is certain that hens lay 
 eggs ' is an assertion directly about the statement that hens lay 
 eggs, indirectly about the fact that hens lay eggs. It seems- 
 that it does not matter much which form we use, and in this 
 particular case it does not matter ; but in many cases it is 
 more convenient to assert indirectly our mental attitude towards 
 a fact through a statement than to assert directly our mental 
 attitude towards a fact, and this for two reasons. In the first 
 place, a statement is a form of words that may embody fact. 
 or pseudo-fact or quasi-fact, or what is not fact ; and we can 
 express our attitude of mind towards such a statement without 
 inconsistency ; but we cannot without inconsistency, or at least 
 
 ON BELIEF. 
 
 191 
 
 incongruity, express our attitude of mind towards what is not 
 a fact We can say with propriety ' I believe hens lay eggs, 
 but we cannot say without a sense of irksomeness and impro- 
 priety * I disbelieve hens lay chickens,' or ' I disbelieve hens do 
 not lav e-gs ' for in these expressions we are virtually asserting 
 and deny hig the same fact in the same breath. ^ The incon- 
 gruity is at once removed by inserting the relative that,^ for 
 bv so doing we transfer our opinion from the fact or quasi-fact 
 to a statement of it. There is no sense of impropriety or 
 incongruity in saying ^ I disbelieve (the statenient) that hens 
 lay chickens ' or ^ I disbelieve (the statement) that hens do not 
 
 lay eggs.' ^ . 
 
 The second reason that induces us often to prefer an asser- 
 tion about a statement to an assertion about a fact is that by 
 usin- the former method of expression we have at oiir com- 
 mand a larger choice of shades of meaning than is available by 
 the other mode : and with both at our command, the number 
 of shades of meaning that we can express is largely increased, as 
 we may see from the following examples. 
 
 ' It is certain ' means ' I affirm that the statement is true ; 
 and corresponds nearly with ' I know that the fact is so', but 
 is rather more emphatic. . 
 
 'It is true 'means 'I admit that the statement is true ; 
 and corresponds nearly with one of the senses of I believe that 
 the fact is so ', but is perhaps more emphatic. 
 
 ' It is probable ' means ' I incline to believe that the state- 
 ment is true ' ; and corresponds in some cases with ' I think 
 'in others with ' I suspect that the fact is so.' 
 
 ' It is possible ' means ' I do not deny that the statement 
 may be true ' ; and corresponds with ' I dare say the fact is so 
 
 or ' may be so.' ^i. ^ ^u 
 
 ' It is doubtful ' means ' I neither affirm nor deny that the 
 statement is true ' ; and corresponds pretty accurately with ' I 
 do not know whether the fact is so or not.' ... 
 
 In all these cases the last assertion expresses the attitude of 
 mind towards a fact ; the second expresses the attitude of mind 
 directly towards a statement, indirectly towards a fact ; and the 
 first expresses explicitly an assertion about a statement, and 
 
 i I 
 
 V ) 
 
192 
 
 ON CAUSATION. 
 
 implicitly the attitude of the mind towards, first, the statement, 
 and second, the fact, or quasi-fact, expressed in the statement. 
 
 In the foregoing discussion the term ' fact ' has been freely 
 used. It is time to define it, and to ascertain how it is 
 expressed. Of course, originally and strictly, a fact means a 
 thing done, but few words have been more abused, battered 
 and transmogrified ; and by many writers and speakers it is 
 used pretty much in any sense they please at the moment. I 
 discard all these meanings, and define it for the present purpose 
 as anything existing or happening, in the past, present, or 
 future. To us, however, a fact is always a relation, and we have 
 no means of expressing, or indeed of apprehending, a fact 
 except as a relation. Our expression of a fact is always in the 
 form ' A is related to B,' and this empty form is filled out and 
 vitalised by substituting appropriate terms for A and B, and by 
 interposing between them a verb as a connecting link, as for 
 instance, Hens lay eggs. This is an expression of a fact, and 
 the fact is expressed by asserting a relation of laying, which 
 means in this case origination or parentage, between the eggs 
 and the hens. It is manifest that there are as many relations 
 known to us as there are verbs to express them ; and more- 
 over, we are constantly inventing new verbs to express relations 
 that we newly appreciate. I mention this because the teach- 
 ing of every book on logic is that there is only one relation 
 between things, and that there is only one verb in any language, 
 namely, the verb * to be ' ; or if there is any other verb, it 
 cannot be used to express a fact, or to argue or reason about 
 it. This is what logicians teach, although they use all the verbs 
 in the dictionary as freely as anyone else, and cannot, any 
 more than other people, conduct their arguments without 
 these verbs. The doctrine is a curious superstition, and well 
 worthy the attention of students of irrational beliefs, but it 
 need not detain us now. 
 
 Things exist or do not exist, happen or do not happen. 
 Our business, if we think about them at all, is to bring our 
 attitude of mind into conformity with fact, so that if a thing 
 has, does, or will exist or happen, we should so believe ; and 
 if it has not, does not, or will not exist or happen, we should 
 
 ON BELIEF. 
 
 193 
 
 .attune our minds accordingly, and disbelieve. Now, it is a 
 common-place of philosophy that we have no experience of 
 things themselves, but only of their appearance; and with 
 respect to many things that we rightly believe, such as the 
 landing of Caesar in Britain, and the great earthquake at 
 Lisbon, we have no experience even of appearance to go upon. 
 How, then, are we to bring our beliefs into accordance with 
 facts, our disbeliefs into accordance with the absence of facts ? 
 In this way : Between facts, or the existence and happening of 
 things, and our minds, which should be moulded into con- 
 formity with the facts, there is an intermediary, which we term 
 evidence. The facts give rise to evidence, and it is the evidence<^ 
 and not the fact that impresses our minds. Wc can never have 
 any direct knowledge of things or facts external to our minds : 
 all that we can ever know is the evidence for or against them, 
 and it is notorious that evidence may mislead. Still, though 
 it may mislead, it is the only means we have of attaining a 
 knowledge of fact, and therefore it is of the utmost importance 
 that we should discover what is evidence and what is not ; what 
 evidence is trustworthy and what is not ; what are the sources 
 of error in interpreting evidence, and how they may be avoided ; 
 what kinds of evidence there are ; and, generally, ascertain how 
 to bring our beliefs into accordance with the best evidence we 
 can get. 
 
 For, as belief should rest upon evidence, so it should be in 
 accordance with the evidence. Of some things, as of the size 
 and position of a possible crater on the other side of the moon, 
 we have no evidence at all, and therefore ought not to have 
 any opinion at all. Of many other things, such as the exist- 
 ence of an enormous sea-serpent, the evidence is imperfect and 
 inconclusive, and towards these the attitude of our minds should 
 be one of doubt or scepticism. We have no right either to 
 believe or disbelieve. Of yet other things, such as the exist- 
 ence of the moon, and the recurrence of the tides, the evidence 
 is conclusive and unassailable, and towards these our attitude 
 of mind should be one of belief 
 
 It is customary to speak of a ' knowledge of the fact,' as if 
 such knowledge were practicable, and indeed frequent ; and no 
 
 13 
 
^ 
 
 194 
 
 ON CAUSATION. 
 
 doubt when the evidence is quite conclusive it would be. 
 pedantic and ridiculous to object to the expression. In such 
 cases we may, for the common purposes of life, leap over the 
 evidence, and conclude that the knowledge and belief conform 
 to the fact ; but the habit of leaping over the evidence has its 
 dangers. It leads very often to accepting a knowledge of 
 evidence as a knowledge of fact ; and to a disregard of flaws 
 in evidence which should make us hesitate. The attitude of 
 hesitation is, however, irksome, inconvenient, and painful ; and 
 few will maintain it until they have trained their minds to- 
 submit to it. 
 
 Evidence. 
 
 Evidence of fact is of three kinds, and is derived from three, 
 sources : evidence of sense, evidence of reason, and evidence of. 
 hearsay ; and any one of these may be conclusive or incon- 
 clusive, convincing or worthless. 
 
 Evidence of Sense, — The evidence that facts fhemselves. 
 afford directly to the senses of hearing, sight, touch, and so 
 forth, is commonly regarded as conclusive and irrefragable. 
 * Seeing is believing' is an aphorism that everyone accepts. 
 That which is palpable cannot be gainsaid. These statements- 
 are in one sense the truest of truths, but in another they may 
 be very misleading. When we have an impression on a sense, 
 when we see a light, hear a sound, or feel a touch, these are, 
 facts of ultimate certainty ; and it is not open to us to doubt 
 that we do experience the sensation ; but a sensation no more, 
 remains a bare sensation when it is received by the mind than 
 a fly remains a bare fly when it is received into a spider's web. 
 In the one case as in the other, the intruder is instantly 
 enveloped in a web of new material furnished by the owner of 
 its new surroundings, which distorts and transforms it, and 
 makes of it a very different thing. The mind is rarely content 
 to receive a sensation and let it remain a bare sensation. It 
 instantly begins to work upon it, to interpret it, and to infer 
 from it to some external fact which corresponds with it and 
 gives rise to it. This is seen by the character of the response. 
 
 ON BELIEF. 
 
 195 
 
 that IS mstantly made by the mind to any sudden and un 
 expected sensation. When we receive a sudden and unexpected 
 flash of light, or sound, or touch, the instant and unfailin- 
 response is ' What's that ? ' The question does not refer to the 
 sensation. We know perfectly well what the sensation is It 
 is a flash of light, it is a loud crack or boom, it is a touch hVht 
 or heavy ; and no investigation can giv^ us any further know- 
 ledge of the sensation itself What the question refers to is 
 not the sensation, but the source or origin of the sensation • 
 not the feeling, but the fact that gives rise to the feeling We 
 say or think ' What's that } ', but if we were to express our 
 meaning with pedantic accuracy we should say ' What has 
 happened ?^' ' What fact has occurred to give rise to this 
 sensation ? The sensation is evidence ; the knowledge of the 
 external fact that gives rise to the sensation is arrived at bv 
 interpreting the evidence ; and the knowledge will be true or 
 false according as the interpretation is correct or incorrect • 
 and so will^ be the belief I hear a booming rumbling noise' 
 and this noise is evidence to me that something has happened 
 in the world outside of me ; but what it is that has happened 
 the noise does not tell me. What conclusion I come to about 
 the origin of the noise must be arrived at by interpretation • 
 that IS to say, by the activity of the mind working upon the 
 materials it possesses. I interpret the sound as thunder I 
 may be right : I may be wrong. It may be thunder, or it 
 may be hea^y guns. The sensation itself does not tell me 
 It IS from the interpretation of the sensation that I derive my 
 belief; and although sensation cannot err, the interpretation of 
 sensation may be very erroneous ; and the moment interpreta- 
 tion steps upon the scene, the chances of error begin. At how 
 early a stage interpretation begins, and how irresistibly it may 
 lead us to false conclusions, are shown by the many examples of 
 w^hat IS called sensory illusion. If we touch a marble with two 
 adjoining fingers, we have two sensations of touch which we 
 interpret as due to one object ; but ii we cross the fingers and 
 again ^ touch the marble simultaneously with both, we cannot 
 help interpreting the sensation as due to two objects The 
 familiar experiences afforded by the conjurer and the ventrilo. 
 
1 '» 
 
 ,1 
 
 If 
 I 
 
 I 
 
 y 
 
 196 ON CAUSATION. 
 
 quist give us examples of illusion of the senses of sight and 
 hearing, illusions which are in every case due to misinterpreta- 
 tion of what we see and hear ; but it would be quite a mistake 
 to suppose that misinterpretation is limited to the cases in 
 which others lay elaborate schemes to deceive us. When sight 
 or hearing is impaired, misinterpretation of these sensations 
 becomes frequent, and it is occasional with all of us, as the 
 many cases of mistaken identity testify. For a long time it 
 was in doubt, and for aught I know it may still be in doubt, 
 whether there are or are not rectilinear markings on the surface 
 of the planet Mars ; and the interpretation of the markings, if 
 they exist, is still a matter of dispute. 
 
 Interpretation of a sensation consists in likening it to some 
 previous sensation that we have had, the source of which we 
 have ascertained. Thus, when I hear that deep booming 
 sound, I mark its resemblance to such sounds that I have 
 heard in the past, and say ' That must be thunder,' or ' That 
 must be guns.' Which source I choose must depend upon my 
 recollection of the sounds of thunder and of guns ; and upon 
 which of these the sound that I now hear most resembles. 
 W^hen I identify a man as one that I have seen before, my 
 interpretation of the visual sensation depends on the faithful- 
 ness of my memory of what I have seen before, and on the 
 degree of likeness that I can trace between the present sensa- 
 tion and the memory of the past sensation. Accuracy of 
 interpretation depends partly on faithfulness of memory, and 
 partly on the ability to discern likeness and difference. 
 
 A powerful aid to interpretation, in cases in which it can be 
 employed, is the checking of the evidence of one sense by the 
 evidence of another. If a thing looks as if it were hard or soft, 
 we can test that interpretation by the sense of resistance. If it 
 looks as if it were at a certain distance, we can traverse that 
 distance, and note whether we reach it. The corroboration of 
 one sense by another usually removes the possibility of doubt ; 
 but we find that seeing is not always believing, or if it is, 
 the belief may be erroneous ; and although the evidence 01 
 sense may usually be trusted, and in almost every case must be 
 trusted, yet possibilities of error lurk in the interpretation of 
 
 ON BELIEF. 
 
 197 
 
 this evidence, and there are cases in which these possibilities 
 ought to be borne in mind, and judgement, even of the evidence 
 of sense, suspended. 
 
 Evidence of Reason, — As we have just seen, the whole 
 cogency of the evidence of the senses lies in the way we inter- 
 pret it ; and we interpret it by the activity of the mind working 
 on the material with which the senses furnish it. Interpreta- 
 tions of sensations, or perception, \s, in short, an example and 
 a method of reasoning ; very elementary reasoning it is true, 
 but still reasoning of a kind, and of a kind that is the model of 
 a very large part of our reasoning. The only difference is that 
 in the rest of this kind of reasoning the material is not the 
 direct evidence of the senses, but other evidence — evidence that 
 has been gradually accumulated in our minds by experience 
 and hearsay, and which the mind can work upon and interpret 
 in the same way as it works upon and interprets the evidence 
 of sense ; that is to say, by remembering, and by tracing likeness 
 and difference between the things remembered. The general 
 rule is that the more completely the evidence harmonises and 
 accords with what we know to be true, the more readily we may 
 accept that evidence as evidence of truth; and vice versd,thQ more 
 incongruous and discrepant the evidence with what we know 
 to be true, the more cautious we should be in admitting it. 
 
 This raises the crucial question, What do we know to be 
 true? and this question has, curiously enough, two answers, 
 one derived from reason and one from experience. 
 
 As we have already found, a statement is not bound to 
 conform to truth. We can form the statements * Paris is in 
 London,' * The Thames is run dry ' ; but we cannot assert 
 either of these statements, for assertion means that we intend 
 what is asserted to be received as true. Now there are certain 
 statements that are not merely false, like the instances just 
 given, but that the mind refuses to entertain. A statement 
 consists, as we have already found, of two terms predicated to 
 hold towards each other a certain relation. It is possible to 
 take any two terms we please, and to couple them in a state- 
 ment by any verbs we please, and the resulting statement then 
 
 ^^jue!hu,j! 
 
198 
 
 ON CAUSATION. 
 
 1:1 '. 
 
 m : 
 
 
 comes before the mind for acceptance, or rejection, or any other 
 operation the mind can perform upon it. With this wide liberty 
 of concocting statements it is evident that we can, if we please, 
 form some that are nonsensical, and that convey no idea to the 
 mind, as for instance * Two o'clock is solid,' ' Limestone reasons 
 downward,' ' Hens shine pocket-books.' Such statements the 
 mind has nothing to do with. It neither accepts nor rejects, 
 but disregards them. It is impossible even to consider whether 
 they are true or not. There is a second kind of statement 
 which is not nonsensical, which can be entertained by the mind, 
 but which the mind instantly rejects, because it cannot conceive 
 the terms to stand in the relation which the statement purports 
 to assert. Such are the statements * The hen laid an Qgg larger 
 than itself,' ' The space was enclosed by two straight lines,' 
 * The solid body is liquid,' ' The pain was unconsciously felt/ 
 In these cases the relation expressed in the proposition is in- 
 conceivable. The mind cannot put the terms together in the 
 relation that is predicated. It is intuitively perceived that the 
 statement is false, and that its contradictory is true. Thus, by 
 the light of reason alone, by the very nature of the terms, it is 
 seen that they cannot exist in the relation predicated, and that 
 the contradictory of that relation must be true. The realisation 
 of this truth does not rest upon experience. It is independent 
 of experience, and apart from it ; and it is the highest and 
 most assuredly certain truth that the mind can entertain. We 
 need no experience to assure us that the hen did not lay an 
 tgg larger than itself, that the space was not enclosed by two 
 straight lines, that the solid body is not liquid, or that the pain 
 was consciously felt. Such truths, which are the contradictory 
 of what is inconceivable, are called Axioms ; and as already 
 said, axiomatic truth, or axiomatic certainty, is the uttermost 
 certainty of belief that the human mind can entertain. The 
 terms are bound up indissolubly in the relation, and no effort 
 of mind can tear them asunder. 
 
 Axiomatic truth is the contradictory of what is inconceivable, 
 Herbert Spencer arrived at the conclusion that the test of 
 truth is the inconceivability of the opposite, and this doctrine 
 was strenuously opposed by Mill ; who declared that it is no 
 
 ON BELIEF. 
 
 199 
 
 . 
 
 test, since many things, such as the antipodes, the rotation of 
 the earth, and gravitation, were inconceivable to our forefathers, 
 but are become commonplaces to us. The contradictory of 
 these beliefs was accepted by our forefathers as true, and is 
 known by us to be false. The contradictory of what is incon- 
 ceivable is therefore, in Mill's opinion, not necessarily true. It 
 may be as mistaken and false as any other belief Spencer felt 
 that he was right, and he was right ; but he had great difficulty 
 in meeting Mill's objection, and never met it satisfactorily. He 
 maintained that in the cases adduced by Mill, the relations that 
 had been thought to be inconceivable were not really incon- 
 ceivable, but had been thought to be so because they were not 
 clearly represented or pictured in the mind. When, however, 
 we do clearly represent a relation in the mind and find it indis- 
 soluble, it must, so Spencer said, be true, and we cannot help 
 admitting that it is true. Spencer rested his defence upon a 
 wrong ground, and it is easy to demolish. There is no difficulty 
 in clearly representing or picturing in the mind the antipodes 
 and the rotation of the earth ; and both their existence and its 
 contradictory are easily conceivable, and have in fact been 
 conceived. The true defence is that Spencer, when he said that 
 the contradictory of the inconceivable must be true, was refer- 
 ring to axiomatic truth ; Mill, when he denied it, was referring 
 to empirical truth ; and thus both were right and both were 
 wrong. That the earth rotates, or does not rotate, is a relation 
 whose terms do not refuse to exist in either relation. The 
 mind can put them together in either relation, and does not 
 intuitively perceive that either is true or false. Which is true 
 and which is false is for evidence drawn from experience to 
 decide. But to perceive the truth of an axiom we need no 
 evidence. We need no evidence to enable us to decide whether 
 a hen can lay an ^gg larger than itself, or whether two straight 
 lines can enclose a space, or whether a pain can exist without 
 being felt, or whether a solid thing is liquid. As soon as we 
 have experience enough to comprehend the relation that is 
 asserted, we see that it must be false. The mind refuses to 
 entertain it, and asserts at once that the contradictory must be 
 true. Mill's instances are not of this nature. Whether they 
 
200 
 
 ON CAUSATION. 
 
 ON BELIEF. 
 
 20r 
 
 II 
 
 i 
 
 are true or false is matter for discussion : it is for experience to 
 decide : their truth or falsity is not intuitively perceived the 
 moment they are stated and the mind grasps their meaning. 
 In short, they are not axiomatic truths or certainties, they are 
 empirical beliefs. 
 
 Rightly apprehended, an axiomatic truth cannot be doubted. 
 Of course we may frame a statement which purports to deny 
 an axiom, but it is beyond human capacity to doubt an axiom, 
 and anyone who pretends to do so is either deliberately lying, 
 or is so muddle-headed as not to know the meaning of what 
 he says. 
 
 Empirical certainty is a degree less assured than axiomatic 
 certainty. Empirical truth, once established, must be believed ; 
 but it is always open to us to conceive the contradictory, 
 though we may not be able to believe it. Empirical truth is' 
 as its name implies, founded upon experience, and our warrant 
 for it is experience alone. Conceivably the fact might be 
 otherwise. In experience it never is and never has been other- 
 wise. Consequently, as long and as far as our knowledge that 
 it never has been otherwise extends, we are precluded from 
 believing that it ever will be otherwise. It is to us an empiri-: 
 cal certainty. The basis of empirical certainty is constancy in 
 experience, by which is meant, in the first place, the accumula- 
 tion of instances without exception. The greater the number 
 of experiences of a given fact that we can accumulate without 
 finding any exception, the firmer becomes our belief that the 
 fact is universally true, and that no exception will be experi- 
 enced ; until at last conviction becomes unshakeably assured. 
 
 No one nowadays doubts that mankind are necessarily 
 mortal — that every man, woman, and child that now lives will / 
 die, and that there is no one now living who was alive two 
 centuries ago. This is not an axiomatic truth. The contra- 
 dictory of it is not only conceivable, but has by many people 
 been believed. There have been few primitive peoples who 
 have not believed in the immortality of some chief or promi- 
 nent character who impressed himself powerfully on their 
 minds during his lifetime, and became the centre of legend 
 after his death. We have our King Arthur, our Merlin, our 
 
 f 
 
 i 
 
 Thomas of Ercildoune, the Germans their Frederick Barbarossa, 
 Denmark its Holger Danske, and other nations their analogous 
 characters; but such beliefs have prevailed only among 
 primitive people, belonging to small communities without 
 authentic memorials of past times, and without any critical 
 faculty of interpreting evidence. As far as we know, there has 
 never been an instance, there is no evidence worth the name, 
 that of all the millions of millions of mankind who have lived 
 in past ages anyone has escaped the fate of dying. 
 
 This complete constancy in experience of the sequence ot 
 death upon life in men is of itself sufificient to produce in us an 
 empirical certainty that the sequence never will be broken, and 
 that all children who are born into the world will die sooner or 
 later ; but this constancy in experience is reinforced and cor- 
 roborated by a constancy of far greater extent. Men are living 
 beings, and with respect to what they have in common with 
 other living beings we can argue from other living beings to 
 men ; and our constant experience of all living beings, animal, 
 and vegetable alike, is that after a period of life they die. More 
 even than this, the slowly accumulating experience of mankind 
 through the centuries, and the insight that we have gained in 
 the last few generations into the processes of nature, all go to 
 show that destruction, dissolution, decay, or at least change, is 
 the universal law of all material things ; and man's body is a 
 material thing. This vast concourse of experiences, to none of 
 which can any permanent exception be shown, breeds in us a 
 corresponding fixity of belief in the inherent mortality of man, 
 a belief that is not axiomatically certain, for it is not difficult 
 to conceive that a man should go on living for an indefinite 
 time, and indeed, many have conceived, and even in a sense 
 believed it ; but the belief is empirically certain, for, with the 
 evidence now at our command, it is impossible to admit that 
 any man has lived much beyond a century, and this complete 
 constancy in our experience of an indefinitely great multitude 
 of cases of men and other living things, justifies and compels an 
 empirical certainty of belief 
 
 A very similar empirical certainty is that heavy bodies, if 
 unsupported, fall to the ground. This, again, is not an axio- 
 
 M« m Mjm ^.MtmH^ 
 
 I 
 
 I 
 
202 
 
 ON CAUSATION. 
 
 [1* 
 
 matic certainty. It is easy to imagine heavy bodies without 
 support remaining suspended above the ground ; and the case 
 of Laputa shows how easily it can be imagined, while the case 
 of Mahomet's coffin shows that it can be not only imagined but 
 'believed. We have, in fact, many experiences of heavy bodies 
 without visible support which yet do not fall to the ground. 
 Every flying bird is such an instance, and we frequently see 
 leaves, straws, and other things tossed about by the wind with- 
 out falling. In such cases we soon learn that the air, though 
 invisible, is a support, and that the rule is not really broken ; 
 and so at length, by the accumulation of innumerable experi- 
 ences without any real exception, experiences constantly re- 
 curring throughout every moment of our lives, we are driven and 
 compelled to adopt as quite certain the belief that heavy bodies, 
 if unsupported, will inevitably fall to the ground ; and although 
 we can imagine exceptions, we cannot believe that there ever 
 has been or ever will be a real exception, and the belief is 
 inescapable. It is an empirical certainty. 
 
 These, it will be seen, are cases of that enumeratio simplex, 
 ubi non reperitur instaiitia contradictoria which Bacon and sub- 
 sequent logicians have scouted as utterly untrustworthy as a 
 ground of belief It is unquestionable that it is, on the contrary, 
 the ground of the most certain and inescapable of all our 
 empirical beliefs. 
 
 It is true that it is not always a satisfactory ground of belief, 
 or at least that the evidence may be so interpreted as to give 
 rise to beliefs that are unwarranted. The ancients believed, on 
 somewhat similar grounds, that every swan is and will be white, 
 and that no such thing as a black swan is credible. Since their 
 day, black swans have been discovered, and they have been 
 shown to have been in a sense wrong ; but they were not wholly 
 wrong. Let us see what were the grounds of their belief. 
 They had had many experiences of swans, and in every case 
 without any exception the swans had been white. According 
 to rule, therefore, it seems that they were justified in entertain- 
 ing the certain conviction that all swans thereafter discovered 
 would be white, and no swan of any other colour would ever 
 be found. It will be seen at once, however, that the number 
 
 ON BELIEF, 
 
 203 
 
 of cases, in which swans had been seen and found without ex- 
 ception to be white, were as nothing in comparison with the 
 number of cases in which unsupported things had fallen to the 
 ground, or with the number of cases in which men and other 
 living beings had proved their mortality by dying. A very 
 important element in confirming the certainty of an empirical 
 belief is the number of cases in which the conjunction or rela- 
 tion has been witnessed and found to be constant. Constancy, 
 however complete, that extends over but few cases ought never 
 to be accepted as ground for a certain belief; and the acceptance 
 of a few cases as proof of a general law is one of the most 
 fertile sources of erroneous belief If, upon visiting a new 
 country, the first man we met was six foot four, or even the 
 first two or three men we met were more than six feet high, it 
 would be manifestly very unsafe to form the belief that ail the 
 inhabitants of that country were exceptionally tall. Although 
 the relation would be constant in experience as far as experi- 
 ence went, the experience would be far too limited to justify a 
 belief in the general prevalence of the relation. A similar error, 
 not so gross, but similar in kind, though less in degree, vitiated 
 the belief of the ancients in the universal whiteness of swans. 
 The instances were too few. 
 
 But there was another and more serious error. We have 
 seen how enormous a corroboration and justification for the 
 belief in the mortality of men is afforded by the constancy in 
 experience of the mortality of other living things, that is to 
 , -say, of things that, for the purpose of the argument, are like 
 men. It is manifest that if all birds, and still more if all 
 animals also, had been white, and no instance of a bird or an 
 animal of any other colour had ever been known, the certainty 
 of the belief that all swans are and will be white would have 
 received a tremendous corroboration. But this is not so. Not 
 only animals, but birds also, exhibit a great diversity of colour, 
 and even some birds that are, for the purpose of the argument, 
 not unlike swans, such as geese, exhibit some diversity of 
 colour. Therefore the belief that all swans are and will be 
 white was risky, and should have been held lightly, and subject 
 to further experience. 
 
204 
 
 ON CAUSATION. 
 
 
 i«. . 
 
 I' * 
 
 i 
 
 i 
 
 1 
 
 Nevertheless, as far as it went, and as they understood it, the 
 behef of the ancients that all swans are white was justified, and 
 was true. By ' swans ' they meant the species and breed of 
 swans that they knew, and with respect to these ' swans ' they 
 were right ; for no swan of that species has ever yet been of 
 any other colour, as far as we know, in the two thousand years 
 that have elapsed since their day ; and with every generation 
 of these swans the appearance of an individual of any other 
 colour becomes less likely. The black breed of birds resembling 
 swans, that has since been discovered, we call by the name of 
 swans, but they are not the same kind of swans as were 
 known to the ancients, and might very well have been called 
 by some other name. They may be swans, but they are swans 
 with a difference ; and as far as the swans which the ancients 
 believed to be always white are concerned, their assertion was • 
 true. 
 
 It is clear, I think, that empirical beliefs in the general truth 
 of relations always depend upon the constancy in experience of 
 those relations, and are the more justifiable, the more confirmed, 
 and the more inescapable, the greater the number of instances 
 in which the experience has been constant. 
 
 Supposing, however, that the relation is not constant in 
 experience, but is liable to exceptions, in which its terms are 
 experienced dissevered from one another, what effect will this 
 inconstancy in experience have upon the attitude of mind ? 
 For instance, cancer is generally a fatal disease, but every now 
 and then there occurs a case in which a cancer, after having 
 advanced to a certain stage, shrinks up, dwindles away, and 
 disappears, or leaves a mere remnant, and the patient recovers, 
 his former health. If we have had, directly or indirectly, that 
 IS to say by ourselves or by others, experience of a very large 
 number of cases of cancer, every one of which has been fatal 
 our belief in the fatality of cancer will be strong in proportion 
 to the number of cases in which a fatal issue has without 
 exception occurred. Now if a case occurs in our experience in 
 which recovery ensues, we have two alternatives of interpreta- 
 tion. We may believe that we have been mistaken in sup- 
 posing that the disease is cancer, and may adhere to our 
 
 ON BELIEF. 
 
 205 
 
 ^original belief that cancer is always fatal ; or we may modify 
 our belief about the fatality of cancer, and admit that though 
 it is very generally fatal, yet it is not always so. There is no 
 doubt that in every case in which the experiences of constancy 
 have been very numerous, the safest course is the first. We 
 should assume that we have been mistaken in supposing that the 
 constancy has been broken, and should require the most strin- 
 gent and unimpugnable evidence, first that the tumour really 
 was cancer, and second that it really did shrink up, dwindle 
 away, and allow the patient to recover. Unless and until 
 evidence on both these points is established beyond reasonable 
 doubt, we ought not to admit that cancer can ever recover. 
 But if these two matters are satisfactorily established, then we 
 can no longer doubt, but must modify our original belief, and 
 admit that, although cancer is generally fatal, yet it is not 
 universally or necessarily so. 
 
 The number of cases in which cancer has been watched and has 
 been found to be fatal is many thousands, many tens of thousands, 
 perhaps many hundreds of thousands ; and the number in which 
 the result has not been fatal has been few, perhaps a few dozen, 
 perhaps a few score ; but in any case, constancy in experience, 
 even if complete, and even in hundreds of thousands of instances, 
 does not warrant the assured certainty that is derived from the 
 constancy in experience of the fall of unsupported bodies. Ot 
 this we have experiences by myriads, experiences daily and 
 hourly all our lives long, experiences that are common to our- 
 , selves, our companions, our predecessors, and as far as we know 
 to the whole human race. To such constancy in experience 
 no exception ought to be admitted on any ordinary evidence. 
 Any apparent instance to the contrary should be prima facie 
 disbelieved, and no approach to belief should be admitted until 
 the instance has been examined, and tested, and re-examined, 
 and retested, in every possible aspect and by every possible 
 means. Mere eyewitness of such an instance is worthless, and 
 should not be admitted for an instant. If a person thinks he 
 sees a heavy object, such as a table or a man, rise from the 
 ground and remain suspended in the air without visible means 
 of support, he should assume as a matter of course that there 
 
 i: 
 
 M 
 
2o6 
 
 ON CAUSATION. 
 
 ON BELIEF. 
 
 207^ 
 
 I 
 
 ;l) 
 
 H' 
 
 lit 
 
 are means of support invisible to him ; and in the improbable 
 event of his investigating the matter closely and still discover- 
 ing no means of support, his proper attitude of mind is to 
 assume that the means of support are so cleverly hidden that 
 he is not able to discover them. In face of the universal ex- 
 perience of the human race that the relation is constant in 
 experience, he would be guilty of unjustifiable credulity if he. 
 believed, on the evidence of a single instance, that an exception 
 could occur. 
 
 In many things experience exhibits little or no constancy. 
 In this country there is very little constancy in the sequences, 
 of the weather. A fine day may be followed by a fine day, or 
 it may be followed by a wet day ; and as there is no constancy 
 in experience, so there can be no assured belief, and in any 
 individual case no assured expectation. We may, indeed, be 
 able on other grounds to forecast with some success what the 
 weather will be to-morrow, but we cannot do so on any con- 
 stancy in experience of the succession of a wet day on a fine 
 one, or vice versa ; but though we cannot rightly form any 
 belief of the kind of weather that will occur on the day 
 following a wet day or a fine day, we are not altogether de- 
 barred from belief On the contrary, our experience has been 
 in some respects constant, and consequently in some respects 
 we have very definite and positive beliefs about the weather 
 generally. As far back as our records go, and as far as the 
 memory of the oldest inhabitant serves, the weather in these 
 islands has been generally inconstant, with occasional spells of 
 uninterrupted rain, and occasional spells of uninterrupted fine 
 weather. We are therefore justified in believing, and indeed 
 compelled to believe, that in future the weather here will con- 
 tinue to exhibit these characters, and that we shall go on 
 indefinitely having spells of fine weather, spells of wet we'ather, 
 and spells of changeable weather. In short, in whatever 
 respect experience has been constant, even in inconstancy, in 
 that respect we are justified in believing, and compelled' to 
 believe, that it will continue to be constant. 
 
 Empirical belief rests, therefore, upon two elements in expe- 
 rience : first on the absolute number of the experiences of tha 
 
 m 
 
 II 
 
 particular relation. If these experiences are sufficiently 
 numerous, and are all one way, we must believe that the- 
 experience is necessary and will continue. The smaller the 
 number of experiences, even if they are all one way, the less 
 are we justified in arguing to other similar cases, and the more- 
 cautious should we be to keep an open mind. When expe- 
 riences are not constant, but are sometimes one way and 
 sometimes another, we are not warranted in believing that any 
 new experience of the kind will be either way ; but when 
 experiences of one way preponderate numerically over expe- 
 riences of the other way, and the total of experiences of both 
 kinds is very large, we are justified in believing, and compelled 
 to believe, that a similar proportion will hold of such expe- 
 riences in the future, and that the chances of a new experience 
 being one way rather than the other will be in the proportion 
 that the ways have borne to one another in the past. 
 
 Evidence of Hearsay. — Immense numbers of our beliefs 
 are based on this kind of evidence ; and as it is manifestly 
 open to more sources of error than either of the other kinds, 
 it is incumbent on us to examine it with some care. It is 
 more open to sources of error than the other kinds because all 
 evidence, including that of hearsay, is ultimately derived from 
 experience or from reasoning, and hearsay evidence has 
 additional sources of error in the untrustworthiness of the- 
 witness, either from bias, or from deliberate intention to 
 deceive, or from defect of memory, or from other causes. 
 
 With respect to every assertion, the first necessity is that it 
 shall be understood in the same sense by both the assertor and 
 the recipient, and this is often not the case. The ancients 
 asserted that all swans are white. A modern zoologist will 
 assert that all swans are not white — that in fact some swans 
 are black. Either assertion may be true or false, according as 
 it is understood. If by 'swans' we mean the familiar Euro- 
 pean species, the ancients were right ; but if we include in the 
 term ' swans ' birds that are sufficiently like the European species 
 to be included in the same genus, and extend the name so as 
 to cover this genus, then the moderns are right and the ancients 
 
208 
 
 ON CAUSATION. 
 
 ON BELIEF. 
 
 I 
 
 'I 
 
 are wrong. Again, there is another sense in which both are 
 wrong. No swans are wholly white or wholly black. The 
 legs and beak of the white swan are not white, and the beak of 
 the black swan is not black. Still, it would be pedantic and 
 unnecessary to deny, on account of these exceptions, that the 
 one is white or the other black. Neither statement is strictly 
 accurate ; but this does not matter, because both assertor and 
 recipient are quite aware of the exception, and both under- 
 stand the assertion in the same sense. If I assert that all 
 gnats bite, the assertion is true in one sense and false in 
 another. It is true that gnats of every species bite, but the 
 males of some species do not bite ; and while it is true that the 
 females of every species bite if they get the chance, many 
 individual female gnats never do get the chance, and therefore 
 in this sense all female gnats do not bite. Still, though 
 exception may be taken to the mode of expression, the mode 
 of expression is of no importance as long as both parties 
 understand it in the same sense. 
 
 Having ascertained that we understand the assertion in the 
 sense in which it is meant, the next question we are to ask our- 
 selves is Is it true ? It may be true or false, and if false, it 
 may be false with or without the knowledge of the assertor ; in 
 other words, it may be a lie or a mistake ; and if a mistake, it 
 may be a sane or an insane mistake — it may be a sane 
 mistake or a delusion. 
 
 The first question to determine is whether the witness is a 
 witness of truth as far as he knows it — whether he is asserting 
 what he believes to be true, or what he knows to be false, or 
 recklessly, what he does not know to be either true or false. As 
 to this we must be guided mainly by two considerations : — by 
 the previous record of the witness, and by his responsibility. 
 The previous record of the witness for truthfulness and careful- 
 ness must go far to determine our judgement whether he is 
 truthful and careful on this occasion. That is unavoidable, and 
 in accordance with the general principle of induction, by which 
 we infer that that which has been constant in experience will 
 continue, and infer it with a confidence proportioned to the 
 number of uncontradicted experiences. In the absence of any 
 
 209 
 
 ^ i 
 
 such record, we ask, first, if he Is responsible, and our opinion 
 of the bonafidts of his assertion rests largely upon the degree 
 of his responsibility ; that is to say, upon how far he would 
 suffer in reputation by telling a lie. Hence we are always 
 ready to accept as truthful in intention the assertions of 
 prominent persons on important and public occasions, and 
 accept them the more readily the more prominent the position 
 of the assertor, and the more public and important the occasion 
 on which the assertion is made. It is true that our faith is 
 sometimes unwarranted, but the rule is a wholesome one, and is 
 usually justified. 
 
 A third consideration, which must influence us, rightly or 
 wrongly, is whether the assertor has a personal interest in 
 getting the assertion accepted. 
 
 Having determined that the witness is in intention a witness 
 of truth as far as he knows it, the next stage is to estimate how 
 far he does know the truth, and this \s the matter that is most 
 often neglected. In order to estimate it we must consider, 
 first, what his opportunities of knowing are, and second, what 
 his bias is likely to be. 
 
 It is surprising how implicitly most people receive as true 
 the evidence of those who have no better means of knowledge 
 than the recipients themselves. ' They say ' is an authority 
 that is accepted with unquestioning submission, without even a 
 query as to who are the ' They ' who say it. The whole fabric 
 of popular superstition about what is lucky and what is unlucky 
 . rests entirely upon what 'They say.' Who * They' are or what 
 opportunities ' They ' have of knowing, are questions ' that are 
 never asked, and that the superstitious people who entertain 
 these beliefs never think of asking. They would, I fancy, 
 regard it as presumptuous, and almost irreligious, to ask. But 
 it is not only with respect to beliefs like these, that ^x^ prinid 
 facie irrational and absurd, that the omission is made. Many 
 prevalent beliefs on other subjects are equally without rational 
 foundation. There is a prevalent belief, for instance, that 
 cigarette smoking is more injurious to the smoker than the 
 smoking of pipes ; and this belief is widely and firmly held on 
 no better ground than the belief that it \s unlucky to look at 
 
 14 
 
2IO 
 
 ON CAUSATION. 
 
 the new moon through glass. Occasionally we may obtain the 
 assurance that ' doctors have said it,' but it is usually found 
 that ' doctors ' is but another expression equivalent to ' They/ 
 Supposing, however, that the dictum can be traced to a doctor, 
 I have never found, and I have often tried to run to earth the 
 origin of this strange belief, — I have never found that the 
 doctor has any better ground for his belief than the fact that 
 * They say.' In discussing the matter with an intelligent person 
 who is not a doctor, I have been told that he felt bound to 
 accept the dictum of a doctor, because the doctor was in a 
 position to know. This is an instance of simple faith com- 
 parable with the confident assurance that was reposed in the 
 middle ages on the assertions of an ecclesiastic. It is clear to 
 anyone who gives a moment's thought to the matter, that to 
 determine whether cigarette-smoking is or is not more deleterious 
 to health than pipe-smoking would require a very long and 
 aborious course of experimentation, such as no one has ever 
 yet undertaken, or an accumulation of non-experimental 
 evidence, such as has certainly never been attained. 
 
 The belief that canker and other diseases of fruit trees are 
 due to sourness of the subsoil rests also upon what * They say.' 
 Most people who are not gardeners accept it upon the evidence 
 of gardeners, and assume that gardeners ' must know.' But 
 why must they know ? I am pretty sure that no gardener 
 except myself has ever tested the subsoil to discover whether it 
 is sour, nor is there any evidence to show that if the subsoil were 
 sour it would be any more favourable to the growth of canker 
 than an alkaline subsoil. 
 
 Many people believe in the occurrence of what has been 
 called telepathy, and many believe in the genuineness of the 
 'manifestations' of 'spiritualism.' In some cases the belief is 
 founded upon the experiences of the believer, but there is now 
 besides these a large number of people who hold these beliefs 
 upon hearsay evidence. Certain persons profess their faith in 
 the existence of telepathy, or in the ' manifestations,' and a 
 ruck of other persons hold the belief on the evidence of those 
 witnesses, without any critical enquiry into the worth of that 
 evidence. ' So and so,' they say, ' that is, Sir Roland Illogic 
 
 ON BELIEF. 
 
 21 I 
 
 and Sir William Hookes, say so, and they are scientific men ; 
 and what a scientific man says on a scientific subject is good 
 enough for me. I myself have no personal experience, but as 
 a sensible man I must accept the opinion of an expert. No, I 
 shall not suspend my judgement about it. You might as well 
 ask me to suspend my judgement about the revolution of the 
 earth. To me it seems that the sun goes round the earth, 
 but scientific men who are in a position to know tell me that 
 it is not so, and that the earth goes round the sun, and I 
 accept their evidence. How can I consistently accept the 
 evidence of scientific men in the one case, and reject it in the 
 other ? ' 
 
 The reasoning seems plausible on the face of it, and is repre- 
 sentative of such a large body of opinion on so many subjects 
 that it is worth examination. The assumption that underlies 
 it is that the evidence of a witness who is a witness of truth, 
 and is in a position to know the fact to which he testifies, 
 ought to be accepted. There is no question about these wit- 
 nesses being witnesses for truth in intention, that is, of what 
 they believe to be truth ; but the assumption that they are in 
 a position to know the facts to which they testify is altogether 
 unwarranted. That we m.ust trust the expert is a sound general 
 maxim ; but before we trust him we must make sure that he is 
 an expert. The greatest possible eminence of an expert in one 
 branch of science adds not a grain of weight to his opinion in 
 another branch of science. However profound may be a man's 
 knowledge of chemistry, his opinion is not on that account 
 more to be trusted than that of a farmer or a fishmonger upon 
 a question of astronomy. But, it may be said, he is accustomed 
 to weigh evidence ? He may or may not be. Many scientific 
 men are very poor hands at weighing evidence ; and in any 
 case, no scientific man has any experience at all in weighing 
 the kind of evidence that is necessary to distinguish between 
 genuineness and imposture in spiritualistic ' manifestations.' 
 The ' manifestations ' are the kind of occurrences that, if not 
 genuine, can only be produced by conjuring tricks, and the 
 only expert whose opinion of them is of any value is a conjurer. 
 The opinion of a professor of electricity or of spectrum analysis 
 
 § 14 
 
212 
 
 ON CAUSATION. 
 
 is of no more value in such cases than the opinion of a ship's- 
 captain or a carpenter. The evidence for the revolution of the 
 earth rests upon quite a different basis. The experts who 
 testify to this are experts in this very subject. The whole of 
 their science is founded upon this supposition ; and upon this 
 supposition is founded the compilation o{ th^ Nautical Almanack y 
 by means of which innumerable ships find their way across the 
 pathless ocean with unerring certainty to their destinations. In 
 other words, conduct founded upon the supposition never leads 
 to experience inconsistent with the supposition ; and this is the 
 conclusive test of truth. 
 
 * They say ' was the foundation, and the only foundation, for 
 the belief in judicial astrology — the belief that the position of 
 the planets, and especially of the moon, influences and regu- 
 lates the course of human lives, and the fortunes and misfor- 
 tunes to which human beings are subject. In the long history 
 of judicial astrolog>% extending over six thousand years, it 
 scarcely ever occurred to any one to ask the crucial question, 
 * What opportunity have the assertors of knowing whether their 
 assertions are true ? What is the evidence on which their belief 
 is founded ?' Moreover, never did anyone test whether conduct 
 founded on the belief led to experiences inconsistent with the 
 belief; or if they did, these experiences were powerless against 
 the overwhelming efficacy of * They say.' 
 
 Galen thought that the arteries carry the vital spirit from the 
 heart to all parts of the body ; and if this is so, there must be 
 a hole in the septum of the heart to allow the spirit to pass 
 from the arteries of the lungs into the arteries of the rest of the 
 body. He taught, therefore, that there is such a hole, and for 
 fourteen hundred years anatomists believed him, and in spite of 
 the plain evidence of their senses, followed his teaching, and 
 believed that a hole is there, although they could not find it ; 
 so strong is the power of ' They say.' He taught also that 
 the veins carry the blood from the heart, and so sure were 
 anatomists that he must be right, that when a valve was found 
 in the azygos vein, a valve which effectually prevents the blood 
 in that vein from flowing away from the heart, they again 
 refused to believe the evidence of their senses, and declared that 
 
 ON BELIEF. 
 
 215 
 
 ihe valve operates in the direction the reverse of that in which 
 they saw it operate. 
 
 It would be a great mistake to suppose that the efficacy of 
 what ' They say ' is abolished in these latter days, or that it 
 influences the minds of the uncultured and the vulgar only. 
 Logicians were told by Aristotle that a universal is necessary 
 in every act of reasoning, and they believed him, and still 
 believe him as faithfully as ever an anatomist of the School of 
 Salerno believed Galen about the hole in the heart. In many 
 arguments, as for instance in the argument a fortiori, there is 
 no universal. Logicians have been trying for two thousand 
 years to find a universal in the argument a fortiori, and they 
 have failed, just as the anatomists failed to find Galen's hole in 
 the heart ; but does this failure modify their belief? Not a bit 
 of it. ' They say ' there must be a universal in that argument, 
 and a universal there must be. To doubt it would be to doubt 
 the omniscience and infallibility of Aristotle, and no logician 
 would dare to be guilty of such blasphemy. What are two 
 thousand years of failure ? Did not belief in judicial astrology, 
 founded on precisely the same kind of evidence, last three 
 times as long? and may not the belief in the universal in 
 reasoning hope for similar longevity ? To doubt it would be to 
 doubt the efficacy of ' They say.' 
 
 For nearly as long ' They ' have said that Insanity is disorder 
 of mind, and disorder of mind is insanity. In vain it is pointed 
 out that that there are many disorders of mind that are not 
 insane, and that there is much in insanity besides disorder of 
 mind. Reason, observation, experience, the plain evidence of 
 the senses, are powerless against the authority of ' They say.' 
 What they have said, that they continue to say, and that they 
 will continue to say to the end of time. In vain it is asserted, 
 in vain it is proved, that what a man says and does is alone 
 enough to prove his insanity, which also cannot be proved 
 without this evidence. ' They say ' it is not, and what ' They 
 say ' must prevail, and does prevail. 
 
 The influence of bias upon opinion has been so thoroughly 
 considered by Herbert Spencer in his Chapters on the subject 
 in the Study of Sociology, that little need be said of it here. 
 
214 
 
 ON CAUSATION. 
 
 There is one kind of bias, however, that Spencer does not 
 mention, and as it is perhaps as frequent as any other, a word 
 may be said of it. We are strongly biassed against any asser- 
 tion made by a person we dislike, and against opinions we 
 dislike. The former is too frequent to need illustration; of 
 the latter the following instances will suffice. A certain pro- 
 fessor of philosophy in Padua asked Galileo to explain to him 
 the meaning of the word parallax, so that he might refute the 
 doctrine it expressed, which was opposed, so he had heard, to 
 the teaching of Aristotle. Another admirer of the Stagyrite 
 refused to look through a telescope, lest he should be convinced 
 of the existence of Jupiter's moons. It would be a great error 
 to suppose that this attitude of mind did not survive the six- 
 teenth century. The greater part of the opposition to the New 
 Logic, and to the doctrine that madness is disorder of conduct, 
 rests on precisely the same prejudice. 
 
 From the foregoing considerations it would appear that 
 hearsay evidence is open to so many sources of error that it 
 can never have any great value, and that it would be most 
 dangerous to base any firm belief on any important subject 
 upon hearsay alone, or even chiefly. Such an attitude would 
 be very erroneous, even if we could adopt it ; and we cannot 
 adopt it. It is quite true that hearsay evidence should be 
 received with care and discrimination ; and it is true also that 
 all our most grossly and flagrantly erroneous beliefs are founded 
 upon hearsay ; but on the same evidence are founded some 
 beliefs that are but little inferior in justification to the 
 empirical certainties, such as that noise always proceeds from 
 movement, that yield only to axiomatic certainties in justifica- 
 tion and inescapability. Besides the intrinsic credibility of 
 hearsay evidence that arises from our trust in the truthfulness 
 of the witness, and our estimate of his opportunity of knowino- 
 the fact, there are extrinsic circumstances which may add such 
 weight to hearsay evidence as compels us to accept it as 
 true, or may demolish its cogency altogether, and leave us 
 no alternative but to reject it. These are, first, the con- 
 gruity of the hearsay evidence with already existing beliefs, 
 and, second, the concurrence of witnesses ; or we may put it 
 
 ON BELIEF. 
 
 215 
 
 corroboration by experience, and corroboration by other wit- 
 nesses. 
 
 In days when knowledge was less diffused than it is now, a 
 sailor on his return to his native village reported that he had 
 seen in his travels mountains of sugar, rivers of rum, and fishes 
 that flew like birds. The village gossips received the first two 
 items of information with acquiescence, * for,' they said, ' we have 
 seen sugar and rum, and they must come from somewhere ; but 
 ilying fishes are a traveller's tale ; you cannot deceive us with 
 such a cock and bull story as that' The judgement was 
 erroneous, but the principle on which it was founded was cor- 
 rect. It was the comparison of the hearsay evidence with 
 knowledge already in possession, and the reception or rejection 
 of the evidence according to its congruity or incongruity with 
 what is already known. They were wrong in believing in the 
 alleged origin of sugar and rum, because the corroboration was 
 insufficient The known existence of these commodities proved 
 that they must have some origin, but did not point to one 
 origin rather than another. But they were right in disbelieving 
 in the existence of flying fish, for such animals are so incon- 
 gruous with all the experience that the audience had had of 
 fish, that they ought not to have believed it upon mere hearsay 
 from a single witness ; and they were none the less right in 
 spite of its happening to be true. Such a startling incon- 
 gruity ought not to be accepted without strong corroboration. 
 Similarly, when the reported discovery of the X rays reached 
 this country, some scientific men disbelieved it, and many sus- 
 pended their judgement, and refused to believe it until it was 
 corroborated. The latter were undoubtedly right, and the 
 former were not very far wrong. That any rays but those of ' 
 light could affect a photographic plate was so incongruous with 
 all our experience up to that time, that scepticism was not only 
 justifiable but proper. That radiant forces could penetrate 
 solid and opaque substances was, indeed, familiar in the cases 
 of gravitation and magnetism, but neither of these has the power 
 of precipitating silver from its combination in a colloid, and the 
 cases were not in point 
 
 It is customary for the newspapers in the summer, when 
 
 > 
 
2l6 
 
 ON CAUSATION. 
 
 Parliament is not sitting and news is scanty, to make jocose 
 remarks about the sea serpent ; and it is generally assumed 
 that no such animal exists. There is nothing, however, in the 
 evidence we have of the existence of a gigantic sea serpent 
 that is incongruous with zoological knowledge. Many fabulous- 
 animals, such as the griffin, the cocatrice, the phoenix, the 
 centaur, the dragon, are zoologically impossible. They are 
 inconsistent with what we know of the necessary structure of 
 animals. The griffin, for instance, is represented with the body 
 of a quadruped, the claws and head of a bird, and the wings of 
 a bat, and with the ability to fly. Now it is quite beyond 
 question that the ability to fly with wings implies the existence 
 of very powerful muscles, and therefore of very large muscles, 
 such as constitute the breast of a flying bird ; and without 
 such muscles a pair of wings would be of no more use for fly- 
 ing than if they were cut out of paper and stuck on with glue ; 
 but in the fabulous griffin there is no sign of any more muscles 
 than are needed for quadrupedal progression, and we may 
 therefore be sure that such an animal could have no wings. 
 There is no such incongruity in the structure of the sea 
 serpent. The only thing unusual in the reported appearance 
 of the animal is its size, and we know that very large animals 
 do inhabit the sea. There is therefore no reason on the ground 
 of incongruity why we should positivel\' disbelieve in the exist- 
 ence of such an animal as has been described as the sea 
 serpent. It may be wise to suspend our judgement, but that 
 is a very different attitude of mind, and is inconsistent with ■ 
 disbelief 
 
 As long as I can remember, and I am now growing old, 
 * They ' have said that this or that prominent personage has 
 been addicted to drink ; and as long as I can remember the 
 question has been put to me, or to others in my presence, ' Do 
 you believe it ? ' Rightly conceived, the question is an insult 
 to the intelligence of the person to whom it is put. It assumes 
 that he will form a belief, without any adequate grounds for 
 doing so, on the mere authority of what ' They say.' It is on 
 a par with asking if we believe that there is a crater fifty- 
 one and a half miles in diameter on the other side of the 
 
 ON BELIEF. 
 
 217 
 
 moon. There may be, or there may not be ; but as we have 
 no evidence either one way or the other, it would be a sign of 
 weak intellect to believe either way. It is true that the 
 interrogator does not really want an answer to his question. 
 What he wants is to obtain a momentary factitious importance 
 as the retailer of a spicy bit of gossip. The question is merely 
 an excuse for the gossip ; but it does not make the gossip 
 excusable. None the less is it an insult to the intelligence of 
 the person to whom the question is put ; and to meet such an 
 assertion of what ' They say ' with an indignant denial, as a 
 worthy but ill-advised bishop did on one occasion in a sermon, 
 is injudicious and disproportionate. The proper course for the 
 interrogatee is to resent the insult to his intelligence. 
 
 Suspension of judgement is an extremely important attitude 
 of mind, and one that it is frequently most important to adopt ; 
 but it is an attitude of mind that is not always easy to adopt, 
 even for cultivated persons, and one that many persons are 
 quite incapable of They must either believe or disbelieve, 
 and no middle course is possible for them. There are, how- 
 ever, so many cases in which suspension of judgement is the 
 right attitude to adopt, that it is the plain duty of everyone 
 to cultivate this attitude, and not to allow himself to be enticed 
 out of it by anything but evidence. 
 
 In this respect nothing is more important to remember, and 
 nothing is more often forgotten than this : — IV/ioso makes an 
 assertion, upon him lies the burden of proof . The time, labour, 
 paper, ink, and temper that are wasted every year by neglect 
 of this maxim are altogether incalculable ; and the waste is not 
 less, indeed I think it is more, in matters that are called scien- 
 tific, and by men that are called scientific, than in any other 
 field of human endeavour. When we are confronted with an 
 assertion that appears to be false, or pernicious, or extravagant, 
 or baseless, our first and natural impulse is to deny and con- 
 trovert it ; and hence arise most of the endless controversies of 
 scientific men on scientific subjects. The impulse is a natural 
 one, but it is injudicious, and the course adopted is injudicious 
 and unnecessary. When such an assertion is made, the proper 
 course is not to deny it, nor to attempt to controvert it, but 
 
2l8 
 
 ON CAUSATION. 
 
 to call upon the asserter for proof. If, as sometimes happens, 
 he can bring forward no evidence in support of his assertion] 
 cadit qucustio. Except for fanatics and other irrational persons] 
 the matter is at an end. If he responds to the invitation, and 
 brings forward evidence, or what he thinks is evidence, of his 
 assertion, then our duty is to examine that evidence, and ascer- 
 tam whether it does in fact bear out the assertion or not. In 
 many cases it will be found that what is adduced as evidence 
 has no bearing at all on the assertion ; and when it has, it 
 will usually be found that what is merely evidence is put 
 forward as proof 
 
 For there is a vast difference between evidence and proof, 
 a difference that is net often recognised. I have found the 
 assertion of this difference has aroused astonishment and 
 mcredulity when I have made the assertion even to very 
 mtelligent and highly educated men, accustomed to form 
 mdependent opinions. The difference is this :— 
 
 Anything germane to the issue and consistent with the 
 assertion is Evidence of the assertion. 
 
 Proof is evidence that is inconsistent with any alternative 
 assertion. 
 
 Disproof is evidence inconsistent with the assertion. 
 
 Thus, to take an illustration of Lord Bowen's, if a man is 
 seen coming out of a public house and wiping his mouth that 
 IS evidence that he has been having a drink. It is germane to 
 the issue, and is consistent with the assertion. But it is not 
 proof that he has had a drink. It is consistent with several 
 alternatives. For instance, he may have gone in to the public 
 house to fetch a friend out, and that friend may have hit him 
 m the mouth for his pains. But if he has been seen to raise a 
 full pint pot to his mouth, and if when he lowered it the pot 
 was found empty, that is proof that he has had a drink, for it 
 IS evidence that is inconsistent with any alternative. 
 
 If these three principles are faithfully observed :— to lay the 
 burden of proof upon the assertor, to examine the evidence, and to 
 accept nothing as proof but that which is inconsistent with any 
 alternative, we shall effectually safeguard ourselves from be- 
 heving any assertion that we ought not to believe. Unfor* 
 
 ON BELIEF. 
 
 219 
 
 tunately for the cause of truth, this \s not the common practice 
 Not only are assertions commonly received, accepted, and 
 believed without proof, but they are commonly believed without 
 the evidence for them being examined and tested, and even 
 without any evidence, worthy the name, at all. Manv instances 
 have already been given in previous chapters in thi/ book, and 
 many more must be known by experience to every thoughtful 
 person. The belief in witchcraft was supported by abundant 
 evidence, much of it of a very cogent character ; but in no case 
 was there proof, and it is now generally abandoned. I say th^ 
 evidence was cogent, and in fact it was a great deal more cogent 
 and satisfying than the evidence for many beliefs that are still 
 very generally held. Many persons confessed that they were 
 witches, that they used charms and spells and the other 
 armamentaria of witchcraft, that they had personal colloquies 
 with the devil, that they rode on broomsticks, and so forth • 
 and they confessed these things well knowing that their 
 confessions would bring upon them a cruel and agonising 
 death. Yet they confessed-. As to part of these confessions 
 there is little doubt that they were true. The witch believed 
 m the efficacy of spells and charms, and no doubt she did use 
 them. The effects for which she employed them did no doubt 
 in some cases follow. The objects of her malevolence did fall 
 ill ; their cows did slip their calves ; their milk did turn sour • " 
 their children did have fits ; and so forth. The evidence was 
 abundant ; and it was cogent ; but it was not proof It was 
 not proof, but in an uncritical age it passed for proof, and the 
 wonder \s, not that the belief prevailed so extensively, but that 
 It ever died out ; for we find other beliefs now held with equal 
 tenacity, beliefs that have not behind them any of the ancient 
 prescription that attached to witchcraft, and that have not in 
 their favour a twentieth part the tithe of the evidence that 
 witchcraft could show. We should no longer believe in the 
 efficacy of the spell that has been quoted on a previous page, 
 but we still believe in the efficacy of two tablespoonsful three 
 times a day ; and a sick man would consider himself defrauded 
 if he did not get them. 
 
 Such a belief, too, is that in the efficacy of what is called 
 
 \ 
 
220 
 
 ON CAUSATION. 
 
 psycho-analysis. The fundamental doctrine of this strange faith 
 is that every disorder of mind is caused by repressed sexual 
 passion. Of this doctrine there is not only no proof, but there 
 is positively no evidence that is worth the name of evidence. 
 In the first place, the universal repression of sexual passion is 
 a mere assertion, and no proof and no evidence is adduced of 
 any such general state of affairs. Secondly, granting the 
 universal repression of sexual passion, there is no evidence that 
 this repression can produce mental disorder. Not one of the 
 nine or twelve methods, that are set forth in Chapter VI for 
 ascertaining causes, has ever been applied to show that 
 repressed sexual passion has or can have any causal influence 
 in producing mental disorder. The assertion is exactly on a 
 par with the assertion that sour subsoil produces canker in fruit 
 trees. There is no evidence that the subsoil is sour, or if it 
 were that it could cause canker. It is much less rational 
 than the assertion that the positions of the planets govern the 
 fortunes of human beings, for there is plenty of evidence that 
 the planets do exist, but there is no evidence at all that re- 
 pressed sexual passion exists in most cases of mental disorder. 
 Another assertion of the psycho-analyst is that if you have 
 difficulty in recalling a word, the difficulty is caused by an 
 involuntary exertion of will (which is of course a contradiction 
 in terms) or an unconscious exertion of will (which also is a 
 contradiction in terms) by which the word is thrust out of the 
 memory. There is no evidence of any such exertion of the will, 
 and a contradiction in terms is an axiomatic impossibility. It 
 is inconceivable, and its contradictory is the strongest and most 
 assured certainty that the mind can entertain. This uncon- 
 scious volition is exerted because of the association of the 
 forgotten word with some painful experience or painful idea : 
 that is the assertion of the psycho-analyst. Of course, in the 
 multitude of words that are forgotten there must be some that 
 have some unpleasant association ; but there are many that 
 have no such association. How do the psycho-analysts surmount 
 this difficulty ? With the utmost ease. They say ' You 
 cannot remember any such painful association, but it is there 
 nevertheless. The fact that it is painful causes you to drive it 
 
 ^■ ^ E ^ 
 
 ON BELIEF. 
 
 221 
 
 out of your mind, and so to forget the association. The word 
 is painful to you, but you do not know that it is painful. The 
 pain is unconscious pain.' Well, if it pleases them to juggle 
 with words in this manner, there is no reason why we should 
 interfere with such a childish occupation, until they proceed to 
 apply their doctrine with disastrous effects to the treatment of 
 cases of mental disease. Then I think it is time to protest. 
 Then I think every honest man should call upon them for 
 evidence. Not, indeed, for evidence of unconscious pain, for 
 we might as well ask for evidence of a solid liquid, or a round 
 square, or a protuberant hollow ; but for evidence, first that 
 every forgotten word has a painful association attached to it, 
 and second, that if it has, this painful association is the cause 
 of the forgetting. Of course there is and can be no such 
 evidence, let alone proof. 
 
 But although there is not and cannot be any such evidence, 
 the resources of the psycho-analyst are not exhausted. He 
 makes assertions that may be evidence, but that he pretends 
 are proof Look, he says, at the cures that I effect by pro- 
 ceeding on the hypothesis that my doctrine is true ! And he 
 relates case after case that can only be paralleled by So and So's 
 Institute for the Treatment of the Deaf, or Thingamy's Cure 
 for Consumption. It is no doubt quite true that some casas of 
 mental disorder will recover even if treated by psycho-analysis, 
 though how much sooner they would have recovered without it 
 we do not know ; but it is also certain that many cases that 
 might, according to our experience of similar cases, be expected 
 to recover rapidly, remain ill for an indefinite time under 
 treatment by psycho-analysis. I am reminded of a case that 
 was related to me at the height of the craze for treatment by 
 sour milk, which preceded the craze for psycho-analysis. A 
 physician, who had had no experience of cases of mental disease, 
 told me that he had treated by the administration of sour milk 
 a gentleman who, from the physician's account, was suffering 
 from a mild attack of melancholy, ' and ' said the physician 
 triumphantly, ' in six months he was quite well ! ' I did not 
 tell my friend that six months is the usual maximum duration 
 of that malady, and he departed rejoicing in his adoption of 
 
222 
 
 ON CAUSATION. 
 
 such an efficacious mode of treatment. The recovery of the 
 patient was evidence of the efficacy of his treatment, but it was 
 not proof. It was not inconsistent with every other explana- 
 tion. It was a good case of the fallacy post hoc, ergo propter hoc. 
 The effect did follow the alleged cause, but no connection 
 between them was traceable. 
 
 It is a little surprising that in these days, when the merits 
 and wonders of Science are so loudly acclaimed, that so few 
 people, even in a learned profession like that of medicine, 
 should have even a rudimentary notion of what constitutes 
 proof ; of what constitutes evidence ; of the difference between 
 evidence and proof; and of the grounds upon which causation 
 may properly be assumed. It has been the part of Logic to 
 teach these things, but unfortunately logicians have even less 
 knowledge of them than physicians, and it is a safe assumption 
 that anything taught by logicians is false. 
 
 Assertion may be accepted, then, when it \s borne out by 
 ■experience ; but there is another mode in which assertion may be 
 corroborated, and when this mode is fully and freely employed, 
 hearsay evidence may properly become the ground of belief as 
 assured and as certain as even the concurrence of innumerable 
 experiences. This method is the concurrent testimony of a 
 plurality of witnesses. Hearsay evidence becomes more trust- 
 worthy the more numerous, the more unanimous, and the more 
 independent of one another the witnesses ; and when innumer- 
 able independent witnesses concur unanimously in an assertion, 
 that assertion must be accepted, unless it violates our own 
 experience. If, however, the assertion violates our own experi- 
 'Cnce, experience which has been tested, considered, and proved, 
 which is plain and inescapable, then no concurrence of testi- 
 mony, however numerous, independent, and unanimous the 
 witnesses, ought to shake our belief 
 
 Whately argued, ironically, the non-existence of Napoleon 
 Buonaparte, by showing that each witness, or set of witnesses 
 for his existence, taken separately, might have had good reason 
 for lying. His argument was directed against the independence 
 of the witnesses, and is based upon the assumption, which is 
 
 '3^-^3eit^^3m-<^.xi 
 
 ON BELIEF. 
 
 223^ 
 
 sound as far as it goes, that the unanimity of different witnesses, 
 goes for nothing if it can be shown that they had a common and 
 paramount interest in lying. The difficulty of establishing the 
 thesis increases, of course, with the number and variety of the 
 witnesses ; and if the number is small, and all are bound together 
 in a common interest and a common character, it may well be 
 established ; and thus do counsel often try to discredit the cor- 
 roborative evidence of witnesses in courts of law. But when, 
 as in the case of Napoleon Buonaparte, the witnesses are in- 
 numerable, and are of the most divergent interests friends 
 
 and foes, admirers and contemners, rich and poor, natives and 
 foreigners, beneficiaries and sufferers, — the attempt to discredit 
 them all must be hopeless. No one familiar with the history of 
 the time can really doubt that Napoleon Buonaparte existed ; 
 and the belief is as assured and certain as any empirical belief 
 can be. We can no more doubt it than we can doubt that trees 
 grow upward, or that unsupported bodies fall downward. 
 
 Our belief, that is to say the belief of stay-at-homes, in the 
 existence of India, rests upon similar grounds, and is similarly 
 assured and unassailable. We have never been there : we have 
 never seen it : we have no experience of it ; but we cannot 
 doubt it. We can no more doubt it than we can doubt the 
 existence of our own parish or our own home. The belief rests 
 upon no experience of our own : it rests entirely upon hearsay ; 
 but upon the hearsay of witnesses innumerable, independent, 
 and unanimous. It is the accumulated evidence of at least 
 ,five generations of men. The witnesses belong to many 
 countries, many classes, many occupations, and have many, 
 and often conflicting interests. They are thus completely 
 independent of one another. And they are unanimous. No 
 one has set out to find India and come back to deny its 
 existence. We believe it implicitly, and we ought to believe it. 
 The evidence is sufficient. 
 
 But however numerous, unanimous, and independent the 
 witnesses to an assertion, we ought not to believe it if it plainly 
 contradicts our own plain experience. If ten thousand men 
 of integrity and character should unanimously assure me that 
 the sun gives no light, or that it rises in the West and sets in 
 
:2 24 
 
 ON CAUSATION. 
 
 the East, or even that on but one portentous occasion it did so, 
 I should not believe them ; and I ought not to believe them. 
 It might be said that an occasion so bizarre could never occur, 
 -and that it is futile to make such a supposition ; but it is not 
 futile. No such number of persons have ever made this par- 
 ticular assertion, it is true; but a very large number have 
 made, and continue to make, assertions that contradict quite 
 as flatly experiences quite as constant. For instance, every 
 writer of a book on Logic, and their name is Legion, for they 
 are very many, asserts that the only form of proposition is the 
 proposition which has ' is ' or ' are ' for its principal verb ; and 
 virtually that this is the only verb in use in any language. I, 
 being familiar with many verbs, and finding many verbs used 
 by every one of the writers who assert that there is only one, 
 refuse to believe this, and rightly refuse. So, too, every writer 
 on Logic declares that every act of reasoning consists in bring- 
 ing a particular instance under a general rule, or proceeds 
 through a universal, as^he calls it. As I know of multitudes 
 of modes of reasoning'which are not thus constituted, and in 
 which there is no universal ; and as logicians admit that there 
 are arguments in which they cannot find a universal, though 
 they have been searching for it for two thousand years, I refuse 
 to entertain this belief. In fact, I could not if I tried. The 
 unanimous testimony of innumerable logicians does not weigh 
 a featherweight with me against incontrovertible experience. 
 Again, innumerable alienists testify unanimously that madness 
 and unsoundness of mind are the same thing ; but when I find 
 many forms of unsoundness of mind that are quite compatible 
 with sanity, and frequently occur in the sane without disturb- 
 ing their sanity in the least, I do not believe, and cannot 
 believe, the testimony of the alienists, even though they are 
 very many, and they are unanimous. 
 
 In the last two cases, those of the logicians and the alienists, 
 it will be seen that although they are numerous and unanimous, 
 yet the third element is wanting — they are not independent, and 
 this it is that vitiates their testimony. The logicians are not in- 
 dependent of one another, for they have all drunk of the same 
 •fount ; they have all been indoctrinated with the same belief 
 
 ON BELIEF. 
 
 225 
 
 from the same ultimate source ; they have all learnt the same silly 
 system ; and none of them has had sufficient independence of 
 mind to trust to his own experience rather than to authority. 
 It is much the same with the alienists. They have all been 
 taught the same false doctrine with the same air of assurance 
 as if it were an axiomatic certainty, and none of them has 
 taken the trouble to compare the teaching with his own 
 experience. No doubt the retention of these beliefs in the 
 teeth of plain and frequent experience to the contrary is partly 
 due to intellectual inertia, or, to use a plainer term, laziness ; 
 partly to timidity of authority, or, to use a plainer term, 
 cowardice ; but it is also largely due to that influence of all 
 upon each which is one of the penalties we pay for the benefits 
 of social life. It is difficult to maintain a belief, or to reject a 
 belief, against the unanimous opinion of our fellows — of those 
 of our fellows with whom we are associated. It is the tyranny 
 of what * They say ' that quells our opposition. These beliefs 
 of the logician and the alienist rest upon the same basis as the 
 belief that it is unlucky to spill the salt, or to cross the knives, 
 or to view the new moon through glass, and a hundred other 
 such absurdities. You can no more persuade a logician that 
 he is constantly constructing, and asserting, and denying propo- 
 sitions with active verbs, or an alienist that he is constantly 
 witnessing disorders of mind that are not insane, than you can 
 persuade a seafaring man that it is not unlucky to go to sea on 
 a Friday, or a rustic that it is not unlucky for a hare to cross 
 his path. Superstitions are not assailable by reason, nor do 
 they depend upon evidence ; and counter-evidence has no effect 
 upon them. 
 
 Note on the Meaning of * Fact.' — Strictly speaking, 
 
 a fact is a thing done, and means ' that which has happened ' ; 
 and in this sense I have defined and used it in previous 
 writings. In this book I have somewhat extended the mean- 
 ing of the word, and the extension needs justification. The 
 extension to that which exists, or has existed, and also to that 
 which happens or is happening, needs but little justification, 
 •and .will, I think, be generally allowed. That which exists has 
 
 \ 
 
 \ i 
 
 \ 
 
226 
 
 ON CAUSATION. 
 
 come to exist by way of some happening ; and though it is 
 not itself, strictly speaking, that which has happened, it is the 
 result of 'that which has happened ; and the same is true of 
 what has existed. There would be little or no impropriety in 
 speaking of the existence of the earth or of Julius Caesar as a 
 fact. The real need of justification is for the extension to the 
 future. Can we justifiably speak of that which will certainly 
 happen as a fact ? Manifestly, in the strict meaning of the 
 term we cannot. But there is no other word that will cover 
 both what has happened and what is about to happen, and 
 a word to cover them both is wanted. I have therefore taken 
 this liberty with the word ' fact ' in this essay, and for the 
 present purpose ; but in other connections I should still use it 
 
 in its strict sense. 
 
 Sir Clifford Allbutt takes me to task for speakmg of the 
 ' fact ' of gravitation. This, he says, is an illegitimate use of 
 the word, and an instance of the detestable misuse, which I 
 deprecate as much as he does, of the term ' fact ' for the term 
 * theory.' Gravitation, he would say, is not a fact, but a 
 theory to account for facts. The facts are that ponderable 
 bodies move towards each other, and we account for this move- 
 ment, this fact, this actual happening, by the theory that they 
 attract each other. Manifestly he is right, and at first I was 
 inclined to confess aliquando dormito ; but on retracing the 
 course of my thought, I find the use defensible. As explained 
 in the text, we have no direct knowledge of fact. All that we 
 have direct knowledge of is evidence ; but when the evidence 
 is conclusive, it is legitimate shorthand to speak of our know- 
 ledge as if it were knowledge of fact. Now, if ponderable 
 bodies do attract each other, that is fact : that is what happens ; 
 and in any individual case of attraction, such as a heavy body 
 falling to the ground, the appearance of falling is evidence of 
 the f^ct of falling ; and the fact of falling is evidence of the 
 attraction that produced the fall. And in the latter case the 
 evidence we now have is as conclusive as in the former. The 
 fact-in-itself we do not know : we know only the evidence for 
 if but the evidence that the body falls is conclusive, and 
 therefore we may speak of the fall as a fact ; and I submit 
 
 '■i n > 
 
 ON BELIEF. 
 
 227 
 
 that the evidence of gravitation is quite as conclusive, and that 
 we may, without undue straining of the meaning of the word, 
 speak of gravitation also as a fact. At any rate, we may sch 
 speak of it in any individual case. 
 
 Summary, 
 
 The different meanings of 'believe' are defined, and the 
 meanings of various cognate expressions explained. An asser- 
 tion of any degree of belief or disbelief expresses an attitude of 
 mind either directly towards a fact, or, while directly towards a 
 statement, indirectly towards the fact stated. 
 
 A fact means anything existing or happening, in the past,. 
 
 present, or future. 
 
 Belief ought to conform to fact, but cannot be directly 
 related to fact, for we have no direct knowledge of fact. 
 Between belief and fact there is always the intermediary of 
 evidence. It is evidence and not fact that impresses our minds, 
 and when we have brought our belief, or the want of it, into 
 accordance with the evidence, we have done all we can, and can 
 
 do no more. 
 
 Evidence is of three kinds : — Evidence of sense, evidence of 
 
 reason, evidence of hearsay. 
 
 Evidence of sense is certain as to the sensation only ; but 
 sensation is of little value until it is interpreted, that is, until 
 its source or cause is arrived at by the elementary process of 
 reasoning called perception. This process may be faulty, and 
 the percept false, or erroneous. 
 
 Evidence of reason gives us two criteria of certainty. That 
 which cannot be conceived is certainly false, and its contra- 
 dictory is certainly true, and constitutes an axiomatic truth or 
 certainty. It is necessary, in using this test, to be careful not 
 to confuse, as Mill and Spencer did, inconceivability with 
 
 incredibility. 
 
 Empirical certainty rests upon constancy in experience. 
 That relation which ♦has been found constant (2>. never con- 
 tradicted) in experiences diverse and incalculably numerous, is 
 true for us, and cannot be believed to be false, although its 
 contradictory may be conceivable. 
 
^i8ihf 
 
 228 
 
 ON CAUSATION. 
 
 If the relation is not constant in experience, then the degree 
 of beh'ef ought to correspond with the proportion that the 
 positive instances in experience of the relation bear to the 
 negative instances, in which the terms of the relation occur apart. 
 The more nearly constant in experience the relation, the more 
 carefully should apparent exceptions be scrutinised. 
 
 Evidence of hearsay may be maximally trustworthy or may be 
 worthless. The following are the criteria to be depended on : — 
 
 (i) The statement must be understood in the same sense by 
 the receiver as by the assertor. 
 
 (2) The witness must be a witness of truth so far as he 
 knows the truth. 
 
 (3) The witness must have means of knowing the truth. 
 
 (4) The hearsay evidence must not be inconsistent, or even 
 incongruous, with experience. 
 
 Whoso makes an assertion, on him lies the burden of proof. 
 No attention should be paid to bare assertion unsupported by 
 evidence. 
 
 Evidence is anything germane to the issue, and consistent 
 with the assertion. 
 
 Proof is evidence inconsistent with any alternative to the 
 assertion. 
 
 Disproof is evidence inconsistent with the assertion. 
 
 The evidence of a single witness may be received in propor- 
 tion to his previous record for truthfulness, and in proportion 
 to his responsibility, that is to say to the ill-consequences that 
 would accrue to him if he were found to have given false testi- 
 mony ; also to his freedom from interest and bias in making 
 his assertion. 
 
 The evidence of a plurality of witnesses is valuable in pro- 
 portion to their independence of one another. Evidence of 
 many independent witnesses goes to prove an assertion if they 
 have means of knowing the truth, and if the assertion is con- 
 sistent with experience. Otherwise, the evidence of witnesses, 
 however many and however unanimous, has no value. 
 
 ADLARD AND SON AND WEST NEWMAN, IMPR., LONDON AND DORKING. 
 
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