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ELEMENTS OF LOGIC. 
 
 tkANSLATED FROM THE ORIGINAL SPANI 
 
 REV. J. BALMES, 
 
 JAMES M. SPELLISSY, M. A. 
 
 ^DOPTBD BY THE ^ROTKERS OF THE pHRISTIAH 
 ^CHOOL^S 
 
 " Of THf 
 
 cr 
 
 O'SHEA & CO., 10 BARCLAY STREET 
 
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 •oaordlBff to act of Coniprea. . the ye&r 1973, by T. O'gznu, la 
 Ot (« of tlM Lilmniui ot jnB«ri««. at Wv'gbiaftBn. 
 
INTRODUCTION. 
 
 LooiO, or the Art of Reasoning correctly, is the most importaal 
 diHcipline that can mark a school or a college. The Greek and th« 
 Latin, the modern tongues, geometry, the calculus, natural philosophy in 
 eadi of its parts, and several other branches easy to be mentioned, are all 
 highly useful studies ; but their utility is far inferior to that of Logic ; and 
 it must be declared to be an unfortunate mistake to give them precedence 
 over it. A principal end of education is to train the scholar so as to be 
 ■uccessful in life. The whole success of life, however, essentially de- 
 pends on having an understanding capable of reasoning well on the 
 onciasions which life presents. But Logic, and Logic alone, whether 
 natural or acquired, confers this faculty. Logic, therefore, should be 
 the leading study, a sine qua non even, wherever the young are 
 educated. Man is a rational being. Therefore, let him know how to 
 exercise his reason. No accomplishment can balance a deficiency in 
 this respect. 
 
 Thus far, Logic has been a greatly neglected study in the United 
 States. Mathematics, chemistry, geography, the languages, ancient and 
 living, have put it out of doors in the majority of schools and college*. 
 It is an insane procedure against truth and intellect, and even morals, 
 for which adequate reparation cm never be made. The act has kept 
 away from tens of thousands of noble minds the nourishment and the 
 Inspiration, the grace and the finish, to which, certainly, they had a 
 most sacred claim, and with which in society they might have done great 
 things. 
 
 Let it not be said that Logic is a ditficult study. It is less difficult 
 than the material branches for which it has been unwisely expelled. 
 B'our years are required for the mathematics ; the Greek and the Latin 
 demand seven ; German, French, and Italian need a very long term ; 
 Algebra itself cannot be mastered in a short period. Logic can be quite 
 ■uocesafuUy studied in one year. All are bom endowed with natural 
 
 219771 
 
^ INTRODUCTION. 
 
 Logic ; and, therefore, all are bom with an innate capacity for an eaa; 
 acquisition of it. Of what other branch can such a statement be made f 
 Of one only — which is Ethics, for a natural Ethics comes into the world 
 with all men. The real difficulty with the most useful aad most nobl« 
 art of Logic is, that, hitherto, it has been persistently excluded from th« 
 schools. It has been made a stranger in its own household, and th« 
 mention of its name excites groundless conceits and opposition. 
 
 The book now presented is a translation from the Spanish of th« 
 masterpiece o*' Balmes, one of the most able philosophers of moieia 
 timeb, and one of the saintliest priests Catholic Spain ever produced. 
 He, endowed with the highetst gifts of mind and disposition, made St. 
 Thomas his exemplar in learning and vii'tue ; and there is a common 
 admission that, among thn followers of the Angelic Doctor, there are 
 but few names which are more eminent than that of Balmes. His 
 work on " Catholicity and Protestantism in their Effects on European 
 Civilization" is the most esteemed work of the kind in'print. His two 
 volumes on transcendental metaphysics is without a superior in eloquence, 
 depth, and completeness. His minor works on the philosophy of 
 grammar, on mathematics, etc., etc., are all unexcelled. But his chief 
 work is his Logic, the same which is now for the fii-st time presented 
 to the public in the English language. 
 
 Balmes wrote his Logic when in the prime of his experience, learning, 
 and talents. He devoted to it all his gifts and erudition. All who are 
 acquainted with the work, and who are well versed in the writings of 
 other authors on the same subject, hold it to be much the best that can 
 be found. It contains every thing that is essential, within the con- 
 venient limits of one hundred and thirty-one pages, 12mo. Most other 
 Logics are confined, it may be said, to the training of the reason alone; 
 in general, they are harsh and dry ; but few of them are fervid in their 
 style ; every one of them is iselessly large ; and, as a rule, they all 
 fail to cast seeds of ambition in the student's mind, and to make him feel 
 hi» dignity as an intellectual and moral being. Not so, in any degree, 
 with the present work. It completely trains the whole man, in hii 
 lenses as well as in his understanding, for the function of reasoning 
 correctly in all the career of life ; in style it is sufficiently terse, yet 
 glowing and eloquent; being only a hundred and thirty-one pages in 
 Kize, it makes an easy course; and, from end to end. it carries the 
 scholar with it, brightening and strengthening all his faculties, giving 
 him a full exhibition of his endowments, and igniting in him the 
 unbidon to make the Trub, which is the first object of Logic, and Honor, 
 
INTRODUCTION. yu 
 
 which is the natural rule of the will, the guiding stars of his existenea. 
 This is no overdrawn picture of Balmes' Logic. The student wh« 
 masters this book — and it is easj to master it — acquires an eminent 
 conception of life, and he is trained in intellect and sense. 
 
 Let H not be supposed that this liOgic is suitable for senior studenti 
 alone. Che illustrious author avoided that unfortunate exclusiveness. 
 The work is designed alike — and, being a Logic, it is properlj so d©- 
 signed — for the advanced boys and girls in the upper classes in grammar 
 •chools, and for the Sophomores, Juniors, and Graduates in colleges ani 
 universities. Whoever can study the ordinary text-books of Engiidb 
 grammar, can study Balmes' Logic ; and it is not more certain tha*. the 
 former are indispensable in acquiring a true knowledge of the English 
 tongue, than it is that the latter is without an equal in the art of training 
 the reason and the sense. -^^.^ 
 
 The publisher humbly conceives that he is doing an important good 
 to Catholic education in issuing this book. Hitherto no adequate or suit- 
 able text-book of Logic was available. The opportunity of introducing 
 the very best is now afforded. Let it be generally tmbraced. The 
 good fame of institutions, the true good of scholars of each sex, and high 
 interests of the Church and nation, are all here at stake in no small 
 degree. All branches are useful. But, over and above all, let our youth, 
 rational, responsible beings as they are, with an untried world before 
 them, know how to reason when they leave school. This is essential , 
 it is so universally ; and it is so for ever. 
 
 The (yhristian Brothers have examined this translation, and they have 
 declared their readiness to introduce it at once into all their schools and 
 institutions. The Brothers are keenly, honorably, and ambitiously alive 
 to the justice and necessity of giving the natural and invigorating dis- 
 cipline of Logic to the young minds under their charge. As far ai 
 their great opportunity and unexcelled spirit of self-sacrifice can ac- 
 complish it, the Roman Catholic boys of America will terminate their 
 school-days, not with crammed, but with trained, intellects. An unfad- 
 ing crown already awaits the devoted sons of La Salle. They hav« 
 eighty thousand scholars in the United States. Their Commencement* 
 now each year show twenty thousand of these boys well finished in 
 grammar and figures, in geography and mechanics, and many in Latin 
 and Greek. Hereafter, their Commencements will exhibit this great 
 number of youths adorned with the noble and essential art of knowing 
 how to exercise their reason for the whole career of life. It is a 
 ■w^fQificeot design in education. It contains an infiuitud« of benefit for 
 
VI 11 INTRODUCTION. 
 
 fiunUiM, for society, for the Church, for the student* themgelve*. Tli« 
 C»rder that achieves it becomes entitled to the tribute of universal reo<^- 
 nition. But the Christian Brothers should not be alone in this matter. 
 They have not a tenth of the Catholic scholars of America. All schooli 
 that aim at any excellence, that appeal to parents for their patronage, 
 ■hould have the purpose and the capacity to teach the pupils intrusted 
 to them the proper way to use their understandings. As the young man 
 who does not know his trade when his apprenticeship is ended may be 
 said to have had a bad master ; so the education, which leaves the grown 
 boys and girls ignorant of the way to reason, may well be put down as 
 wretchedly deficient. Hitherto there has been some excuse for the 
 neglect complain<id of^ for the Logics in the market have all been 
 unsound, cumbersome, exceedingly forbidding. This excuse is now 
 rtiLoved. Balmes was a genius of the first order. He wrote the highest 
 things in the tersest and most engaging way ; and he wins the faculties 
 and excites the ambition of his students at a stroke. There is no other 
 Logic of which such merits can be asnerted. At present our schools, 
 academies, and colleges give Logic to about three hundred pupils. 
 What a cloud over young minds that shows ! Henceforward the number 
 should be a hundred thousand. Balmes, now in English for the first 
 time, gives the opportunity. Let him be tried. He will give the natural 
 reward to professor and to pupil, to parent and to college, to aehotf 
 and to academy. 
 
CONTENTS. 
 
 PRELIMINARY REMARKS 
 
 The object and utility of Logic 1 
 
 The fsculties of the mind , . I 
 
 BOOK FIRST. 
 
 Chafteb L — Rules for the proper direction of the seniei . 7 
 
 *• n. — The imagination 16 
 
 Section I. — The imaginative memory . . 16 
 ** n. — The inventive faculty of the 
 
 imagination . • • .20 
 
 ** nL — ^Internal sensibility 14 
 
 BOOK SECOND. 
 
 PRINCIPAL FACULTY — THE TTNDERSTANDIRG. 
 
 CTkaptxb L — ^The understanding in general . . .29 
 Bection I. — The object of the understand- 
 ing 2S 
 
X CONTENTS. 
 
 Ohaptsb l.^-{C<mtinued.) 
 
 Sectwn n. — Attention 29 
 
 ** III. — Division of the acts of the 
 
 understanding . , ,81 
 
 •• n.— Perception 82 
 
 Section I. — Definition and division of per- 
 ception and of ideas . . 32 
 " n. — Rules for perceiving well . . 38 
 ** III. — Expression of ideas and of their 
 
 ODJects ... . . .40 
 
 ** DL — Auxiliary operations for good perception . 42 
 Section I. — Definition , . , .42 
 
 *' II.— Divisions 46 
 
 ** IV. — Judgment and proposition . . . .49 
 Section I. —Definition of judgment and of 
 
 proposition . . . .49 
 •* n. — Division of propositions . . 50 
 •• ni. — Rules on the extension of the 
 
 subject 52 
 
 ** IV. — Rules on the extension of the 
 
 predicate . . . .64 
 •* V. — The conversion i>f propositions 56 
 •* VI. — The opposition of propositions. 58 
 *• Vn. — Equivalence of propositions . 62 
 •*Vin. — Compound propositions . . 62 
 ** IX.-»— The false supposition • . 69 
 *• X.— The order of terms ... 68 
 ** XI.— Truth, certitude, opinion, doubt 7C 
 
 • T. — ^Reasoning 73 
 
 Section I. — Reasoning in general . * 78 
 
CONTENTS. 
 Ckai*tbb v.— ( Continued. ) 
 
 pAoa 
 Section II. — Definition and divisicn of the 
 
 syllogism . . . .74 
 '* in. — The rules of siwiple syllogisms . 75 
 ** IV. — Figures and modes of the syllo- 
 gism . . . . .79 
 ** V. — Compound syllogisms . . 83 
 ** VI. — The various kinds of argumen- 
 tation . . . . .86 
 •* Vn. — Paralogisms or fallacies . . 89 
 ••¥111. — Reduction of all the rule? <;? 
 
 reasoning to one . . .01 
 
 BOOK THIRD. 
 
 METHOD. 
 
 CaAPTBB I. —The Criteria . . . .95 
 
 Section I. — The criterion of consciousness, 
 
 or of the internal sense . 96 
 
 ** II. — The criterion of evidence. . OS 
 " III. — The criterion of common sense 101 
 •• n. — How we should act on the various questions 
 
 that are offered to our understanding . 108 
 Section I. — General classification of ques- 
 tions 106 
 
 *• n. — Questions of possibility . .106 
 " in. — Coexistence and succession . 114 
 
zii 
 
 CONTENTS. 
 
 Chapter n. — ( Cmtintied. ) 
 
 Section IV. — Questions on the natuie 
 things .... 
 V. — The use of the hypothesis. 
 VI. — Synthesis and analysis 
 VII. — Necessity of labor . 
 VIII. — Observations on reading . 
 IX. — Conversation and dispute 
 X. — Meditation 
 XI. — Pncucal question! 
 
 RlOAjnrULATIOB 
 
 . lai 
 
 . 123 
 
 . 123 
 
 . 125 
 
 . 125 
 
 . 127 
 
 . 129 
 
 . 180 
 
 . Ul 
 
LOGIC. 
 
 PREI IMINARY REMARKS, 
 
 THE OBJECT AND UTILITY OF LOGIC. 
 
 1. The object of logic is to teach us how to know 
 fciath. ^ ^ 
 
 Truth is reality. ^ 8l» 4agu$(fno Has said: 
 Vcmm est id quod e.^t — It is that which is. 
 
 It may be considered in two ways : in things, and in 
 the understanding. 
 
 Truth in a thing is the thing itself. Truth in the 
 understanding is the knowledge of a thing such as it is 
 in itself. The fir^t is called real or objective truth j the 
 second, formal or subjective. 
 
 The sun exists: this is a real truth, or truth in the 
 thing. I know that the sun exists: this is a formal 
 truth, or truth in the understanding. 
 
 Knowledge without truth has no value. What is 
 the use of a multitude of thoughts to which nothing 
 corresponds ? The understanding should pkce us in 
 communication with objects : if it does not apprehend 
 them such as thev are in themselves, the communication 
 is at fault ; for, then, the knowledge acquired does not 
 correspond to the real object, but to a different matter. 
 
 2. Natural logic is the capacity nature has given us 
 for knowing truth. This capacity can be perfected 
 by means of ndes founded in reason and experience. 
 
2 PRELIMINARY REMARKS. 
 
 There are rules to direct the iinderstandhig to thi 
 knowledge of truth, and there are principles in which 
 these rules are founded. The union of these rules 
 and of these principles constitutes artificial logic. 
 
 Logic, inasmuch as it lays down rules, is an art ; 
 inasmuch as it explains such rules, it is a science. 
 
 For example : Art gives the qualities of a good 
 definition J science explains the reason of what i« con- 
 tained in the rule ; art settles what argumentations are 
 legitimate; science supplies the wherefore of their 
 legitimacy. 
 
 Art is a body of rules for doing a thing well ; and it 
 is possible to form a body of rules for arriving at the 
 knowledge of truth f for, truth being the object of the 
 understanding, to arrive at truth, there ought to be a 
 way which it is in the power of reason to discover. If 
 we form this way into a body of rules, we shall have 
 logic as an art. 
 
 The understanding is not a blind faculty. When it 
 follows a way it knows, at least it is capable of 
 knowing, why it follows it; theiefore, it can give the 
 reason of the rules which it observes in coming to tho 
 knowledge of truth. The union of these rules is logic 
 as a science. 
 
 Artificial logic, then, may be defined to be the body 
 of the rules which guide us in knowing truth, and of 
 the reasons in which those rules are founded. 
 
 It is a useful study ; for, if the understanding directi 
 the other faculties, it is clear that it can direct itself, 
 for itself, by means of reflection. 
 
PBELIMINART REMARKS. 
 
 THE FACULTIES OF TIIE MIND, WHICH SHOULD BE 
 GUIDED BY LOGIC. 
 
 3. There are different classes of truths ; for, truth 
 being the thing itself, the difference which is between 
 things implies a difference between truths. 
 
 The difference which is between truths demands f 
 difference in the means to find them out. This is & 
 most important and fundamental rule. To treat the 
 moral and the mathematical sciences in the same way, 
 to investigate truth in letters and in the fine arts as in 
 the exact studies, is to fall into the gravest errors. 
 Each order of truths requires a special method, 
 which it is necessary to follow. 
 
 4. Man, besides his understanding, has other fac- 
 ulties which put him in relation with things. Hence, a 
 good logic cannot be confined to the understanding 
 alone ; it is necessary to apply it to all the faculties, as 
 far as they can assist us in knowing things such as 
 they are in themselves. 
 
 The faculties on which logic should be employed, 
 are external sensibility, the imagination, internal sensi^ 
 bility, or the faculty of sentiment, and, finally, the 
 intellect. 
 
 5. External sensibility is that which is exercised by 
 Llie five senses, — the sight, the hearing, the taste, the 
 smell, and the touch. These place us in communication 
 with the material world. 
 
 6. The imagination is the faculty of reproducing in 
 our interior the impressions of the senses independently 
 of their exercise, and of combining them in a variety of 
 ways without the necessity of subjecting theot to the 
 
t PRELIMINARY REMARKS. 
 
 order in which we have experienced them. Although I 
 have not before me a pyramid which I once saw, I can 
 reproduce its image in my mind : this is an act of the 
 imaginative faculty, which is exercised independently af 
 the sense. I have seen mountains, I have seen gold, 
 but I have never seen a mountain of gold ; still, I can 
 very well imagine one. In which case, I unite the 
 two sensations, gold and mountain, but without any 
 necessity oi having found them joined in reality. 1 
 have seen animals, and I have seen a railway locomo- 
 tive : if I imagine a living monster of the size and form 
 of the locomotive, converting the noise of the latter into 
 a bellowing, and changing the smoke of the engine into 
 a flame of fire issuing from the mouth and nostrils of 
 the monster — in this instance, the union of two sensa- 
 tions forms a being which does not exist in reality. 
 
 7. It is difficult to explain in words what is under- 
 stood by internal sensibility. We say, however, that it 
 is that delicate faculty which places us in relation with 
 objects, independently of the particular nature of ex- 
 ternal sensation, of the imagination, and of knowledge. 
 This definition wiU be better understood by the aid of 
 an example: — 
 
 A man is dangerously wounded ; many see the same 
 wound, they know its cause, they conjecture the result. 
 The sense, the imagination, the knowledge, are alike. 
 In the meantime a woman comes up, and at once a 
 shriek is heard: has she seen, imagined, known any 
 thing which the others have not seen or known ? No ; 
 but she has felt something which they have not felt ; she 
 is the mother of the victim : here we have sentiment. 
 In this faculty are contained all the passions. 
 
 8. The intellect, taken in general, is the faculty 
 of knowing things. Things may be known in one and 
 
PRELIMINARY REMARKS. 5 
 
 *he same way, and still be the objects of very different 
 sensations, imaginations, and sentiments. 
 
 9. Let us unite in one single illustration the exercise 
 of the four explained faculties : — 
 
 We suppose a reservoir of water within view oi 
 several persons. 
 
 The water of the reservoir is the object : first, of ex- 
 ternal sensibility j that is, of the sight ; secondly, of the 
 imagination^ — for one who turns away his eyes from the 
 reservoir, but holds it present in his mind; thirdly, 
 of internal sensibility, — for one of the spectators who 
 remembers having seen a beloved friend drowned in the 
 reservoir, or who experiences from it some other feel- 
 ing, pleasant or disagreeable ; fourthly, of the under- 
 standing , — or for the mathematician who calculates the 
 superficies of the reservoir, for the naturalist who ex- 
 amines the properties of the water, or for the physician 
 who considers the influence of the vapors of the water 
 on the health of the inhabitants of the district. 
 
 10. The knowledge and the judgment of truth are in 
 the understanding alone. The other faculties assist thu 
 understanding, by presenting to it exterior objects, or 
 the feelings of the soul itself; but, in themselves, these 
 faculties do not know. Nature has given them to us as 
 means by which to make a commimication with objects, 
 by which to consider objects under certain forms, and 
 by which to be affected in various ways ; but always 
 reserving true knowledge for the superior faculty, the 
 intellect, because it has the office of presiding over ail 
 the internal and external acts of man. 
 
 11. But so great and so constant is the necessity 
 which the understanding has of these faculties, that, if 
 
D PRELIMINARY REMARKS. 
 
 we did nol know how to properly direct them, we would 
 fall into many errors. 
 
 Hence, although the understanding is the faculty 
 which logic principally proposes to direct, the other 
 faculties cannot be disregarded. 
 
 As these auxiliary faculties have immediate commu- 
 nication with material objects, and as the understand- 
 ing has need of this communication — for it exercises by 
 it the act of knowing — it is a necessity for the under- 
 standing to be presented by these faculties with mate- 
 rial things, or to be excited by them in some way. The 
 consequence of this is, that we are frequently exposed 
 to error by the equivocal conceptions which the auxiliary 
 faculties offer to our minds. The same faculties are, so 
 to speak, certain witnesses Avhose fault as to reality puts 
 the understanding astray. 
 
 And, hence, before treating of the principal faculty, 
 let us endeavor to settle the rules that prevent those 
 faculties, which have been given to us as a means 
 for knowing truth, from being obstacles on the way 
 to it. 
 
 X 
 
BOOK FIRST. 
 
 CHAPTER 1. 
 
 RULES FOR TIIE PROPER DIRECTION OJ THE SENSES. 
 
 12. The immediate purpose of the five senses is to 
 put us in communication with the corporeal world j but 
 their utility is not confined to this, for, when our mind 
 is excited by sensible impressions, it acquires knowledge 
 of incorporeal things. 
 
 To use the senses properly, it is necessary to observe 
 the following rules : — 
 
 1. 
 
 1 3. The organ of sense ought to be in a normal state. 
 The experience of every day tells us what changes 
 
 illnesses produce in our sensations. To a disordered 
 palate, every thing is bitter ; a man in a violent fever 
 experiences an intolerable heat or cold in a temperate 
 room. 
 
 n. 
 
 1 4. It is necessary to observe the relation that exists 
 between the organ of sense and the object ; which re- 
 lation should be that ^hich corresponds to the laws of 
 each, — of sense and object. 
 
 A cylindrical body, looked at from the side, presents 
 its length ; seen in such a way that the line of vision ii 
 
8 Loaic. 
 
 perpendicular to one of its bases, it appears to be a 
 circle. We find water, the temperature of which is 
 unchanged, to be hot or cold, according to the disposition 
 of our hand. One and the same object has different 
 appearances, according as we see it through glasses of 
 new configurations. A field appears to have colors more 
 or less vivid, according as the atmosphere is more or 
 less transparent. 
 
 III. 
 
 15. Each sense should be confined to its own object. 
 
 The senses have characteristic objects : the sight, 
 
 colors ; the smell, smells j and so the rest. When a 
 
 sense is made to give testimony on objects that do not 
 
 belong to it, it is very easy to fall into error. 
 
 We have eaten many times of a dish which has the 
 smell Aj the color J5, and the taste C. Here are three 
 senses — each one with its own object. Suppose that 
 we experience the smell A, without seeing the object 
 from which it arises, and that then we attribute to that 
 object the color B and the taste C. It is clear that, 
 doing this, it would be very easy for us to be deceived, 
 for, doing it, we extend the testimony of a single sense 
 to three different objects f that is, from having found 
 these different qualities united in a remote case, we 
 infer that they should be united in the actual one. It 
 is evident that the same smell A may emanate from a 
 source which has neither the color B, nor the taste (7, 
 but a different color and a different taste altogether. 
 
 The sight judges principally of colors j and, in its 
 way, and under certain circumstances, it also enables 
 us to discern sizes and figures. 
 
 It must be observed, however, that the sight ir not 
 always a competent judge of sizes and figures. We 
 have knowledge of this from the variation under which 
 
THE DIRECTION OF THE SENSES. 9 
 
 distances present to us one and the same size ; from 
 the diffeiences of figure which an object assumes ac- 
 cording to the point from which we see it j and, also, 
 from the illusions which we suffer from perspective. 
 At a certain distance we see an object which appears 
 to be a projection, a moulding, for instance, or some 
 such thing ; but there is, in reality, before us only a 
 smooth surface on which the painter has exercised 
 the genius of his art ; the shade is distributed with 
 such perfection, the effect of the light in the given 
 place has been so accurately calculated, that the object 
 has all the appearance of arising out of the surface, and 
 we take for a real body that which exists only in per- 
 spective. Our eyes, however, have not deceived us ; 
 they have done their part in strict correspondence with 
 the laws of light and vision, — laws, which are fixed 
 and known, as is evident from the use the painter has 
 made of them in calculating the effect of his work. 
 Therefore, the deception does not come from the sight, 
 but from not confining it to its sphere, — light and 
 colors. How could the deception be avoided? By 
 assisting the sight with the touch. 
 
 Seen afar off, a quadrangular tower appears to be 
 round. Here there is no deception from the sight, it 
 presents the object as it should present it j but we 
 ourselves reouire of it that, at too great a distance and 
 from an inconvenient point of view, it should distinguish 
 between a round and a quadrangular figure. 
 
 The hearing, in many cases, indicates with suflfi- 
 cient approximation the distance of an object j but it 
 is always in subjection to the laws of acoustics, which, 
 like those of the sight, are fixed and constant. In 
 listening to a ventriloquist, we think that the voice 
 is from a point much more distant than it is in 
 reality. Dees the hearing deceive us? Noj it gives 
 evidence, as it ought to give it, in accordance with the 
 
10 LOGIC. 
 
 law of its nature ; but we ourselves, ignorant of the 
 exceptional circumstances of the object that sounds, 
 or, if not ignorant of them, yet not accustomed to 
 them, experience a complete illusion, attributing to de- 
 ception from the sense that which emanates from our 
 own precipitation in judging. 
 
 IV. 
 
 16. The senses should assist each other; and f' - > 
 testimony is all the more worthy of belief, the gr^.^ ar 
 the number of them we employ on the same object. 
 The food which has the smell A, the color J5, and 
 the taste (7, has disappeared from the table, and an- 
 other dish, which gives the same smell, takes its place. 
 Here the testimony of the smell is not enough to make 
 US certain as to identity. But if the sight assists the 
 smeii, and we find the same color as well as the same 
 smell, then, in place of one witness, we have twLr that 
 agree, and, consequently, the probability is increased 
 that the food is the same. If, to their testimony, there 
 is added that of the taste, in place of two witnesses 
 there are three ; and in such a case we may be certain 
 of the identity of the object. 
 
 V. 
 
 1 7. The testimony of the senses is worthless, when 
 'hey are in contradiction among themselves : if, in such 
 a case, any sense is to be credited, it is the one which 
 judges the object in the most natural way, and with 
 the least derangement of means. 
 
 A straight staff put obliquely into water appears to 
 be curved ; the hand continually finds it straight. Judg- 
 ment ought to be for the hand, because it is applied 
 immediately to the object ; and the sight should not b« 
 
THE DIRECTION OP THE SENSES. 11 
 
 credited, for it operates through water, which is not its 
 accustomed medium. 
 
 VI. 
 
 18. The testimony of the senses should not be admit- 
 ted, when it is in contradiction with the laws of nature. 
 
 A person alone in a remote place sees bodies mount- 
 ing up in the air, without there being any cause what- 
 ever which could produce such a phenomenon ; it should 
 bo believed to be all the effect of imagination, or of 
 momentary derangement. 
 
 Here we treat only of the natural order, and touch 
 not on miraculous events. 
 
 vn. 
 
 19. The testimony of our senses should not be 
 admitted, when it is in contradiction with the testimony 
 of other men. 
 
 Of several persons in the same room, one sees a 
 spectre passing the house. If the others present set 
 nothing, the apparition is purely fantastical j in reality, 
 it is a work of the imagination. 
 
 VIII. 
 
 20. The testimony of the senses should be sus- 
 pected, when it is in opposition to the regular course 
 of things. 
 
 At a certain distance we see a person who appears 
 from his dress to be a cardinal; but, as there are no 
 cardinals in the country, it is very probable that we 
 are deceived by our eyes. Otherwise, the testimony 
 ^f the sight would be less equivocal 
 
12 Loeic. 
 
 IX. 
 
 21. The testimony of the senses should be confined 
 to the relations objects have with our sensibility, and 
 should not be applied to the internal nature of 
 things. 
 
 An uneducated man is shown a sheet of white paper. 
 A prism is then brought into operation, and at once the 
 paper is covered with beautiful colors. The uneducated 
 roan says : " This is not light : they have acted on the 
 paper with some ingredient : this piece of glass could 
 not produce such a variation." — The man deceives 
 himself. And why ? Because, instead of limiting him- 
 self to the natural object of sight, he has proceeded 
 to judge on the internal nature of things : by simple 
 vision he pretends to know enough of the nature of 
 light to say that it is impossible for it, by passing 
 through a prism, to produce the phenomenon that has 
 surprised him. An object produces in us the sensation 
 of smell J we are not deceived as to the relation of the 
 organ with the object j but if we desire to determine 
 the way in which the organ is affected, and the means 
 by which the impression is transmitted, the organ of 
 smell has nothing to say on these things. 
 
 In general, the testimony of the senses is insufficient 
 fur the act of knowing the internal nature of corporeal 
 objects. Sensibility has been given to us for perceiv- 
 ing phenomena : the determination of the laws to which 
 the world is submitted, and the knowledge of the 
 essence of objects, belong to another faculty, — to the 
 <mderstanding. 
 
 X. 
 
 22 The senses should operate without any preoccu 
 pation. 
 
 Experience teaches that the senses make object* 
 
THE DIRECTION OF THE SENSES, 13 
 
 different to us, according to the preoccupation of the 
 mind. A timid person, on a dark night, easily con- 
 verts into a menacing ghoul a tree, the branches of 
 which are agitated by the wind. He sees two of the 
 branches larger than the others, and from between 
 them there juts up a prominence which is only a part 
 of the trunk, or a branch thicker and shorter than its 
 neighbors. Who can doubt that the prominence is h 
 head, and the two branches two arms ? Your timid per- 
 son is certain of it, for the thing, he is sure, is before 
 his eyes. But it is all the work of the terror under 
 which he is suffering j the terrible spectre is the most 
 harmless thing in the world. If the timid man, thus in 
 alarm, were joined by others who were like him in his 
 craze, they would see as he did, and verify all 
 he should tell them. In such a case, and if no sensible 
 person came up to explain the cause of the con- 
 sternation, the idea of the apparition would remain a 
 fixed fact. 
 
 Opinions, desires, authority, exercise much influence 
 on our senses. It cannot be doubted, for instance, that 
 the favorable judgment in which an orchestra is 
 unanimously held depends greatly on the preconceived 
 opinion that the same orchestra plays the best music, or 
 on the fact that intelligent people, or those esteemed to 
 be so, have given it their praise. At the end of a per- 
 formance all are enchanted ; and it may be that there 
 are some who are really good judges of the entertain- 
 ment 5 but there are many whose tympanum is as thick 
 as the parchment of a drum, and yet who believe, 
 with the best of good faith, that they have duly appre- 
 ciated the melody. 
 
 An irritable man sees, with all clearness, a leering 
 insult on the lips of his enemy, when the latter has no 
 desire to offend, and is only compressing his lips U 
 save himself from violating politeness by a aolem& 
 
14 LOGIC. 
 
 yawn. Demosthenes, when he ran from the battle- 
 field, believed he was overtaken when it was a thorn 
 that stuck in him. 
 
 XL 
 
 23. To perfect the senses, it is necessary to cultivate 
 them with much and well-directed exercise. 
 
 All men have need of this cultivation, even for the 
 most common objects. In all that is really necessary 
 for us, nature cultivates our senses in proportion as our 
 organization develops and strengthens. It is probable 
 that, when we commence to see, we do not see well : 
 and it must be the same thing with the other senses. 
 Experience rectifies our errors; and when we are 
 capable of reflecting on them, nature has already 
 educated us in a manner suflScient to enable us to 
 avoid them. 
 
 The perfectibility of our senses extends to an in- 
 d3finite degree, as is attested by the delicacy acquired 
 by the blind in hearing and feeling. Those who are 
 employed on one class of objects obtain, from practice, 
 a promptitude and perfection of sense, which are sur 
 prising to strangers. The musician accurately per- 
 ceives many little things which entirely escape others, 
 who have from nature as good a faculty of hearing as 
 himself. It is the same thing with the painter. He 
 can point out trifles which are not only of merit in art, 
 but are also real objects for the sight, which persons, 
 with much better eyes than he has, can hardly see. 
 The taste, the smell, the touch, are also perfected by 
 exercise. He who has experience in delicate dishes 
 easily notices the smallest changes made in them. A 
 man practised in aromas, distinguishes between thijm 
 rapidly and correctly. 
 
THE IMAGINATION. Ifi 
 
 CHAPTER 11. 
 THE IMAGINATION. 
 
 24. The imagination has two functions, 1st: Te 
 reproduce in our mind sensations experienced before j 
 2d: To combine these sensations in various ways. 
 The first constitutes the imaginative memory ; the 
 second is the inventive faculty of the imagination. 
 
 Section I. — The Imaginative Memory, 
 
 25. The perfection of the imaginative memory con- 
 sists in representing past sensations promptly and 
 faithfully. Here beauty of combination has Qc place : 
 the imagination should portray, and the perfection of the 
 drawing consists in exactly copying the original. 
 
 26. The imaginative memory is perfectible, like aU 
 the other human faculties : order is its best auxiliary. 
 
 This rule is founded in an ideological principle, 
 namely, that impressions are produced in our mind 
 according to the way in which we have received them, 
 or according to the art and reflection with which we 
 have coordinated them. 
 
 We make a visit to a large manufactory. In one 
 of its departments the raw material is prepared ; in 
 another, various elaborations are carried out; in a 
 third, the finishing hand is given ; finally, in a fourth, 
 the fabrics are arranged for buyers to examine them., 
 If the visit be made with disorder, passing from one 
 object to another, movipg 9yer and hither, now 
 
16 LOGIC. 
 
 admiring this, and then wondering at that, /.nd con- 
 tinuing in this way without any rule, a great many 
 things, no doubt, will be seen ; but it will be difficult 
 to remember them. But, if the visit be made with 
 method, forming, at first, a general idea of the edifice, 
 of its principal parts, and of the uses to which they are 
 destined ; fixing then the divisions and subdivisions of 
 fabrication, following the order of procedure, etc., etc. ; 
 by this means every thing will be deeply settled in the 
 memory ; the recollection of one object will call up that 
 of another ; and, with little trouble, an account can be 
 given of all that has been seen, even after a long time. 
 
 27. It is necessary to practise the act of putting 
 things in order in the memory, as in a book of regis- 
 tration : by this means the most complicated is sim- 
 plified, and one retains without difficulty that which 
 otherwise would be easily forgotten. All do not control 
 the time and patience which are necessary to cultivate 
 the science of mnemonics, but all can employ those 
 means of order which require no scientific study, and 
 which are easily acquired with a little care and 
 reflection. 
 
 28. To record with facility and exactitude, it is con- 
 venient to bind objects in the memory with some rela- 
 tion. This relation may be that of space, of time, of 
 cause, of likeness, according to the things desired to be 
 retained. 
 
 The Belation of Space or Place, 
 
 29. Experience teaches that, to remember a place, 
 it is advisable to make use of the things contained in 
 it. Hence, it is certain that if we desire to record va- 
 rious objects, it can be done all the better and the mora 
 
THE IMAGINATION. 17 
 
 easily, if we connect them with one and the same place. 
 The topography of a country is easily and exactly 
 retained in the memory, if we take a chain of moun- 
 tains, or the direction of a river, or some elevated 
 peak, or any other particular thing, to which to refer 
 foi guidance. 
 
 The Belation of Time, 
 
 80. Events are put in the order of time by takmg 
 those which are the most prominent links in the chain 
 of their occurrence. This i? the foundation of the use- 
 ful custom of dividing history into grand epochs, refer- 
 ring them to the beginning, or to the fall, of an empire, 
 or to any other event very great by its nature or 
 consequence. 
 
 31. We can also distribute the ordinary course of life 
 into points notable by certain events, public or private, 
 remote or near, which by their special circumstances 
 make a deep mark in om- mind; as the commencement or 
 conclusion of a war, a plague, the enthroning or the 
 death of a prince, the decease of a person beloved, a 
 journey, a change of fortune or of social position, a new 
 condition of the family, and other such things. 
 
 It is evident that, if we unite the two relations of time 
 and space, the mark in the memory is engraved with in- 
 creased force ; for it is clear tliat we recollect with more 
 facility a series of events which relate not only to 9 
 much distinguished locality, but also to a very remark 
 able event. 
 
 Belation of Cause and Effect, 
 
 32. The relation of cause and effect, as an aid to 
 memory, should not be factitious, but founded in ih^ 
 
1 8 LOGIC. 
 
 very nature of things. It is easy to forget, — because the 
 mere production of the imagination is easily lost sight 
 of, — that which is not founded in reality. 
 
 33. As far as possible, it is necessary to build on the 
 reality of things : fictions, however ingenious they may 
 be, have not the value of facts. 
 
 It is often said that liars, to e*iape contradicting 
 themselves, should have a great memory ; and this is 
 confirmed by the contradictions into which those persons 
 are constantly falling. The surest way to escape con- 
 tradiction is to speak of things just as they took place, 
 neither adding to them, nor taking from them, any 
 thing. The true witness always attests the same thing. 
 The perjurer falls into many evidences against himself. 
 Here comes in the skill of the judge, to discover the truth 
 in the midst of the impostures with which crime sur 
 rounds it. 
 
 Eelation of Likeness. 
 
 34. The recollection which arises from likeness is one 
 of the most natural. In regard to it the preceding 
 rule is to be observed. The likeness ought to be true, 
 and not a simple stroke of our fancy. An acute intel- 
 lect discovers resemblance between things that are most 
 diff'erent from each other. But, when the resemblance 
 is not real, there is a bad foundation for memory, unless 
 there is some prominent single feature present, which, 
 by its strangeness or beauty, deeply impresses the 
 mind. 
 
 35. The imagination sometimes presents to us as 
 real, things that exist only in our own brain. Persons 
 Bufi'ering from intense fever, have numerous delusioni q* 
 Uiis kind. 
 
THE IMAGINATION. l9 
 
 To avoid the deceptions of the imagination, the Bab- 
 joined rules should be followed ; — 
 
 I. 
 
 36. The testimony of the imagination of the sick is 
 not certain. 
 
 The experience of every day attests this, not only 
 in cases of violent fever, which produces a true delirium, 
 but also in the instance of persons greatly exhausted 
 from the want of food, or from insufficient sleep, or by 
 other causes. 
 
 n. 
 
 37. The testimony of the imagination, to be worthy 
 of credit, should be clear and unchanging. 
 
 Fantastic illusions are generally obscure and confused, 
 mixed with a thousand incoherent things, liable to vari- 
 ation, and seldom firm enough to withstand a change of 
 place or of time. 
 
 III. 
 
 88. The imagination is disentitled to belit t, when it 
 is in opposition to the laws of nature. 
 
 These laws are constant ; they change only by mira- 
 cle ; whereas, the human imagination is subject to the 
 influence of many causes which may derange it. 
 Hence, prudence dictates that, in cases of doubt, it is 
 safer to suspect the imagination, than to accept a change 
 in the laws of nature. 
 
 IV. 
 
 39. The testimony of the imagination should be dis- 
 credited when it contradicts the regular course of 
 things. 
 
20 LOGIC. 
 
 In confirmation •£ this rule, the observations given 
 in regard to the souses may be adduced. 
 
 40. The testimony of the imagination is not to ba 
 accepted, when it conflicts with the testimony of others. 
 
 In general, it is easier for one to be deceived than 
 for many j and if in many we find the generality of 
 men, it may be held for certain that it is the individual 
 who is deceived. 
 
 VI. 
 
 41. To judge with certitude of the testimony of the 
 imagination, we should consult, in case of doubt, reason, 
 the senses, the laws of nature, the regular course of 
 things, the testimony of others, employing these means 
 in accordance with the circumstances of the objects 
 which the imagination presents to us. 
 
 Section II. — The Inventive Faculty of the Imagination. 
 
 42. The inventive faculty of the imagination con- 
 sists in the power of combining various sensible impres- 
 sions, independently of the way in which we have 
 received them. 
 
 The following is the fundamental rule for properly 
 directing this faculty : — 
 
 43. The combination should correspond with the end 
 for which the work of the imagination is designed. 
 
 The principal end of the useful arts is utility; of 
 the fine arts, beauty : the faculty to invent should be 
 subordinated to these ends. It is good to unite the 
 two things, utility and beauty, when it is possible; 
 but the particular end should never be lost sight of. 
 
THE IMAGINATION. 21 
 
 In a dwelling-house beauty should \a subordinate to 
 utility — understanding, by this word, convenience^ in 
 its application to dwellings. In a building intended 
 for a museum of paintings, utility should be subordinate 
 to this object, by making the edifice in the way best 
 calculated to secure for the pictures their proper artistic 
 effect. 
 
 44. The inventive faculty of the imagination has two 
 principles to guide it : science and taste. We under- 
 stand here by science the knowledge of the laws of 
 nature; and, by taste, that indefinable impression 
 which pleasant or unpleasant objects make on us. A 
 gallery is constructed by science, when the architect 
 observes the laws of weight and equilibrium sufficiently 
 to give the work the needed strength ; it is built by 
 taste, if the architect considers only the effect which it 
 will have on the sight. 
 
 45. It is clear that in no case can we put ourselves 
 in contradiction with the laws of nature, sacrificing the 
 principles of science for the inspirations of taste. A 
 palace may be very beautiful and attractive ; but its 
 beauty and splendor would be of little value, if it were 
 likely to tumble down on the heads of its owners. 
 
 46. In every work, it is necessary to distinguish 
 between the parts of science and of taste. In the for- 
 mer, the laws of nature must be strictly observed. In 
 the latter, the inspirations of sensibility should operate, 
 tempered, however, and directed by the councils of 
 sound reason. For the one, there are geometry, me- 
 chanics, and all the natural sciences ; for the other, 
 the study of good models, and application, so as to give 
 as much culture and delicacy as possible to the fancy 
 and to the heart 
 
22 LOGIC. 
 
 47. The preference for the scientific iihould be 
 resolved according to one's profession : the engineer 
 has, principally, need of science ; the painter, of beauty. 
 
 A work constructed according to the true principles 
 of science, has a natural beauty of its own, which, by 
 its simplicity, cannot fail to be agreeable. The simple 
 observance of the scientific principles gives to edifices 
 two qualities which of themselves give beauty : unity 
 of plan, and regularity in the parts. Such a structure 
 is as beautiful in itself as a regular geometrical figure 
 perfectly delineated. 
 
 48. The beautiful, well understood, is not in contra- 
 diction with the rules of science. A marble statue, 
 sculptured in such a way that, according to the rules 
 of mechanics, it cannot stand on its feet, is far from 
 being a fine one. On canvas, the figures are out of 
 order, when they are in contradiction with the physical 
 laws. The artist, who despises the laws of nature, pays 
 for his temerity by the loss of his reputation. 
 
 49. Art does not always follow a beaten track; it 
 sometimes ascends on the wings of fancy, and roams 
 through new spheres. In such cases the artist cuts 
 himself loose from mechanical rules ; but he enjoys 
 this privilege only when he is engaged on objects 
 which are independent of the conditions of the corporeal 
 universe. Who would require a painter to represent a 
 sublime apparition according to the laws of mechanics I 
 In cases like this, every thing becomes cloudy, aerial, 
 fantastic ; bodies may be said to be spiritualized ; the 
 grossness of matter disappears beneath the power of 
 ideas and sentiment. 
 
 In all matters, but especially in those that are con- 
 nected with the imagination, the follomng rule should 
 be observed : — 
 
THE IMAGINATION. 23 
 
 50. No one should engage in a profession for w' ich 
 he has no natural fitness. 
 
 Experience teaches that, while there are some men 
 who are well calculated for mechanical pursuits, there 
 are others who have but a very slight capacity for 
 them. Extremes in ability are as common, as, in ina- 
 bility, they are hard to be found. It is but very few 
 that deserve to be ranked with Mangimele (an Italian 
 boy who was a prodigy in figures) ; but very few also 
 are they who are altogether unable to understand the 
 rudiments of arithmetic. Between extremes, there is 
 an immense field which can be taken advantage of. It 
 is impossible to measure the grades of this field with 
 mathematical precision, but a prudent estimation of 
 one's talents and disposition is, in general, a true guide 
 in choosing a profession. 
 
34 Looia 
 
 CHAPTER m. 
 
 INTERNAL SENSIBILITY, OR THE FACULTY OF FEEUNO. 
 
 61. The feelings should be considered as a species 
 of spring for moving the soul. Man without feelings 
 would be without much of his activity, and, in some 
 cases, he would have none. The will, when moved by 
 the intellect alone, is as cold as the reason which 
 directs it. 
 
 52. Feeling, notwithstanding its utility as an impul- 
 sive cause, is very equivocal as a criterion : a thing is 
 neither good, nor bad, simply because it is agreeable or 
 unpleasant to us ; nor is it in existence, or out of ex- 
 istence, because it may be conformable or repugnant 
 to our desires ; many bad things cause us pleasure, 
 and many good things displeasure ; at one time, that 
 which we desire takes place j at another, the very con- 
 trary occurs. He who takes his tastes for his rule of 
 life, is on the way to inconstancy and turpitude; he 
 who judges of the being or non-being of things by hia 
 dssires, deeply deceives himself. Time dispels such 
 illusions. 
 
 To direct this faculty well, the following rules should 
 be observed : — 
 
 RULES FOR DIRECTING INTERNAL SENSIBILITY. 
 
 I. 
 
 53. A sentiment in favor, or not, of an event, pi\)ves 
 nothing either for or against the existence of Uiat 
 event. 
 
THE FACULTY OF FEELING. 25 
 
 They who forget this rule and decide upon the reality 
 of things by their wishes, expectations, or fears, flatter 
 thrmselves with the idea of favorable results, or tormeat 
 themselves with the apprehension of misfortune : persons, 
 like these, are neither capable of forming an exact 
 conception of what has happened, nor of foreseeing what 
 8 to come. 
 
 n. 
 
 54. A sentiment, approving or condemning an act, 
 proves nothing for or against its morality. 
 
 A revengeful person experiences a strong feeling to 
 murder his enemy. If we judged of the act by the 
 feeling, we would justify the assassination. 
 
 The covetous man has a strong feeling that he is under 
 no obligation to restore the wealth which he has unjustly 
 acquired. Should we judge by the feeling, we would 
 condemn the right. The whole life of the virtuous man 
 is a contest with his passions. 
 
 III. 
 
 55. Sentiment, taken as a simple natural fact, can 
 sometimes be a probable indication, and little less than 
 certain, of another fact. 
 
 An injury or a danger to a person, put before the 
 eyes of some women, would reveal which of them wa& 
 the true mother. No one calls into doubt the wisdom 
 of the famous judgment of Solomon. 
 
 IV. 
 
 56. Sentiment serves in deciding on the merit of 
 vorks in letters and in the fine arts, when the subject 
 laturally belongs to it. 
 
 Tenderness, delicacy, and, in many cases, beauty, 
 have no other judge than sentiment j in such matters, 
 
 2 
 
26 LOGIC. 
 
 unfortunate is the : ritic who, aboinding in talk, 
 incapable of sentiment. 
 
 57. In all the acts of life, sentiment should be guided 
 by morals. 
 
 This is the only sure means to save the heart from 
 evil. Sentimentalism, abandoned to itself, is a peren- 
 nial spring of extravagance and corruption. 
 
 VI. 
 
 58. Even in things that do not belong in a special 
 manner to the jurisdiction of sentiment, it is indispen- 
 sable to listen to the dictates of reason and of sound 
 morals. 
 
 An act may be very beautiful, sentimentally, and 
 yet be profoundly immoral. Who will deny that, in the 
 novel and in the theatre of our day, there are passages 
 and scenes which are not better calculated to enchant 
 the heart than to overthrow its innocence ? The beauty 
 that belongs to the passions is not always absolute 
 beauty. Sentiment presents us things in accordance 
 with our particular disposition : but, to judge these 
 things properly, it is necessary to consider them as 
 they are in themselves, both in their own nature, and 
 in their relation with other objects. 
 
 vn. 
 
 59. To act with energy, it is convenient to excite 
 the sentiment favorable to the thing at stake. 
 
 We all know by experience, that, when we are 
 agitated by one passion, we proceed with greater 
 activity and energy, and that our forces acquire a large 
 increase. 
 
THE FACULTY CB FEELING. 27 
 
 vin. 
 
 60. When we desire to avoid an act, we should stiile 
 the sentiments that are favorable to it. 
 
 To propose avoiding an act, and, at the same time, 
 to conserve and foment in our heart the inclination 
 which impels us to it, is equivalent to giving force to a 
 machine while desiring that it should not move. It is 
 said of certain passions, that the only remedy against 
 them is flight : this maxim can be applied to all the 
 sentiments whose consequences we ought to shun. 
 Man is so very weak, that, to triumph over himself, lie 
 preeminently needs the recourse of the weak, — dex- 
 terity ; and the great secret of this consists in guarding 
 himself from himself, in shunning and encountering 
 himself face to face. 
 
 IX. 
 
 61. The assistance of sentiment is of much utility in 
 works purely intellectual. 
 
 Study prosecuted with enthusiasm, is all the more in- 
 tense and the better sustained. The fire, calm but 
 glowing, which burns in the heart, multiplies the forces 
 of the understanding, increases their light, fecundizes 
 them with its heat, and causes to germinate in them 
 sublime inspirations which change the face of the 
 sciences. There is no man of genius without this 
 exquisite sentiment, which belongs in a special way to 
 the sphere of reason : all great thinkers have moments 
 of eloquence. 
 
 X. 
 
 62. Sentiment, like all the other faculties of the soul, 
 is susceptible of cultivation. 
 
 Experience attests that the hearts of men are 
 
28 LOGIC. 
 
 according as they have been formed by parents Dy 
 masters, and by the various circumstances of life. It 
 is well known that those who make much use of the 
 sentiments in reading, or in the study of artistic objects, 
 acquire a delicacy which others have not. 
 
 XI. 
 
 63. The extreme delicacy of sentiment is not 
 synonymous with its perfection, and much less with its 
 morality. 
 
 There are persons excessively sensitive and deeply 
 corrupt. There are certain women to whom the groan 
 of a patient is insupportable, but who, for all that, 
 would allow their neighbors to die in misery. And 
 there are others, less sensitive, who would divide all 
 they had, and give consolation to every unfortunate crea- 
 ture that came to their door. How many weep com 
 passionately for the sickness of a poodle, and look 
 without any distress on the misfortune of a human being ? 
 Sometimes we encounter associations of sentimental 
 persons whose object is to hinder bad treatment to 
 animals, but who, with the greatest serenity imagina- 
 ble, suffer their fellow-creatures to perish in distress. 
 
 It may, perhaps, be said that, in these cases, there 
 is no delicacy of sentiment but affectation. This, 
 however, is not exact. The sentiment is true: but it 
 is misguided J because, when it reaches an excessive 
 refinement, it is converted into a refined egotism. 
 
 XII. 
 
 64. All sentiment which is confined to individual 
 complaisance, and which does not impel to an act noble 
 in the eyes of reason, is a blind, egotistical instinct, 
 against which we should be on our guard. 
 
BOOK SECOND. 
 
 THE PRINCIPAL FACULTY— THE UNDERSTANDWa 
 
 CHAPTER I. 
 
 THE UNDERSTANDING IN GENERAL. 
 
 Section I. — The Object of the Understanding. 
 
 65. The understanding is the faculty of knowing. 
 Its object has no limits. It is confined neither to the 
 impressions of bodies, like the sense ; nor to the inter- 
 nal representations of bodies, like the imagination ; 
 nor to the determined relations of objects, like the 
 sentiment ; it extends to every thing knowable, and, 
 consequently, to every thing that exists or that can 
 exist. 
 
 Section II. — Attention, 
 
 66. Besides the matter known, attention should be 
 given to the form of cognition, or, in other terms, to 
 the mode in which the understanding acts on the thing 
 known. From this arises the classification of the 
 intellectual acts, and the various rules of which they 
 aie susceptible. We will commence with the condition 
 
80 LOGIC. 
 
 most universal and indispensable in all operations of tha 
 understanding. 
 
 67. Attention is the application of the mind to au 
 object. 
 
 fi8. The first means to think well is to attend well ; 
 without this condition it is impossible to advance in 
 any study, because, without attention, no act of the 
 understanding is duly exercised. 
 
 69. Attention should be firm, but calm ; distrac- 
 tion and disturbance must be avoided. It is necessary 
 to endeavor to acquire sufficient flexibility to pass from 
 object to object, as the course of things demands. No 
 work, however serious and profound it may be, should 
 make us forget that we are men and that we live in 
 the midst of men. 
 
 70. The secret of securing an attention firm without 
 being rigid, and flexible without weakness, consists in 
 studying with method, in taking things in good order, 
 and in discharging obligations with a tranquil and 
 composed mind. 
 
 71. Fault in method is, of itself, a series of distrac- 
 tions ; and disorder in the conduct of things is a con- 
 tinual fountain of disconcertment ; for, summoning 
 attention to many sides at one and the same time, it 
 debilitates the faculty. Disordered passions trouble 
 the heart, and render it impossible for the understand 
 ing to engage itself on objects in the proper way. 
 
 72. All the rules of attention may be reduced to the 
 following : love of truth ; method in study ; order iu 
 all occupations j a conscience, pure and tranquiL 
 
THE UNDERSTANDING IN GENERAL. 81 
 
 Section III. — Division of the Acts of the Understanding, 
 
 73. The acts of the nnderstanding are three : percep 
 tion, judgment, and reasoning. 
 
 74. Perception is the act by which we know a thing, 
 without affirming, or denying, any thing of it. If I think 
 on a color, without affirming that it is black or wliito, 
 or ugly or beautiful, limiting myself simply to thinking 
 on the color, I have a perception. 
 
 75. Judgment is the act by which we affirm or 
 deny one thing of another. 
 
 If I do not confine myself to thinking on a color, 
 but affirm interiorly that it is clear or obscure, agree- 
 able or unpleasant, etc., etc., I form a judgment. 
 
 7Q. Reasoning is the act by which we infer one 
 thing from another. 
 
 If, in thinking on this same color, and in examining 
 its qualities, I infer from these the ingredients which 
 compose the coloring matter, and the way in which they 
 have been combined, — this is a process of reasoning. 
 
82 Loaia 
 
 CHAPTER n. 
 
 PERCEPTION. 
 
 Section I. — Definition and Division of Perceptum 
 and of Ideas, 
 
 77. Objects, to be perceived, must be represented 
 in our mind. This representation we call an idea. 
 The act by which we know a thing, without affirming 
 or denying any thing of it, is denominated perception. 
 
 78. It is essential not to confound the representa- 
 tions of the understanding with those of the imagination : 
 the latter are an internal reproduction of sensations; 
 the former are of a higher order, and they form th« 
 object of intellectual acts. If I remember a circle 
 which I have seen in some situation, limiting myself 
 to the reproduction in my mind oif what my eyes 
 saw, this internal representation belongs to the imagina- 
 tion ; but if I take that circle as a geometrical figure 
 whose properties I consider, then the representation is 
 intellectual. To comprehend the difference between 
 these two ideas, observe that the geometrician and the 
 uneducated man have the simple representation of the 
 circle in the same way. Even the brutes have simple 
 representation. The dog has it of his master ; the 
 bird of its nest ; and so all other animals, in a way 
 conformable to their instincts. 
 
 79. Ideas, coasidered unde*- different aspects, are 
 divided into various classes. 
 
PERCEPTION. 83 
 
 80. The clear idea is that which represents an object 
 with lucidity ; and the obscure, that which is deficient 
 in this quality. 
 
 81. A distinct idea is that by whose clearness we 
 are enabled to distinguish the various properties of a 
 thing; the confused, that which does not confer thia 
 advantage. 
 
 82. The idea which presents to us all the properties 
 of a thing, is called complete ; in the contrary case, it 
 is incomplete. 
 
 83. An idea is exact when it contains, with entire 
 precision and to the exclusion of every thing else, all 
 the properties a thing has ; it is inexact, when it fails 
 in any of these qualities. 
 
 84. It is to be observed that the characters of distinct- 
 ness, completeness, and exactness, are nothing but 
 degrees of clearness ; for it is evident that, the greater 
 the clearness with which an object is presented to us, 
 the better we can see it in every thing that appertains 
 to it. 
 
 85. The simple idea is that which cannot be decom- 
 posed into another. Thus, among imaginative ideas, 
 the ideas of color, of smell, etc., etc., are simple ; and, 
 among intellectual ideas, there is that of being. To 
 those who have not these ideas, it is impossible to explain 
 them in words. 
 
 The compound idea is that which consists of various 
 simple ones, and it is known in this that it can be ex- 
 plained with words. Such, for instance, is the idea of 
 a triangle which is composed of the ideas of three right 
 angles united and enclosing a surface ; and such is that 
 
84 LOGIC. 
 
 of many which contains the ideas of mind, body^ and 
 union. 
 
 86. The abstract idea is that which represents th»» 
 property of a subject, without inherence in it, as wis- 
 dom, virtue, beauty ; the concrete idea is that whicli 
 represents the property as inherent in the subject, as 
 wise, virtuous, beautiful. 
 
 87. The universal idea is that which has application 
 to many subjects ; as that of man, which belongs to all 
 men. The individual idea is that which is confined to 
 an individual. 
 
 88. Universal ideas are also called species and 
 genera. 
 
 89. Species, or the specific idea, is that which con- 
 tains many individuals ; as horse, which takes in all the 
 individuals of that species. 
 
 90. Genus, or the generic idea, is that which embraces 
 many species ; as animal, which embraces the species 
 of the horse, of the lion, and of all other brutes. 
 
 Genus is divided into the highest, lowest, and subal- 
 tern ideas. 
 
 The highest idea is that which is not contained in 
 another; as the idea of being, which is the most 
 universal idea. 
 
 The lowest idea is that which does not contain 
 another; as metal. 
 
 The subaltern idea is that which is contained in 
 higher ideas, and, in its turn, contains others; as 
 body. 
 
 It is clear that different classifications of ideas give 
 different classifications of genera. For instance : sup- 
 
PERCEPTION. 85 
 
 posing that the idea of reptile represents a classification 
 ol animals under which alone we place the different 
 species of reptiles, the genus of reptile will be the last, 
 or lowest ; but, if we admit a classification of serpents 
 into various species, the idea of reptile itself will be 
 a subaltern genus. 
 
 91. The classification of a genus into various species 
 cannot be done without founding it in something. 
 This is called the difference. The genus of animal 
 embraces man and brute : the foundation of this classi- 
 fication is that man is rational, and the brute irrational. 
 The genus, animal, joined with the difference, rational, 
 constitutes the species of man ; the same genus, with 
 the difference, irrational, constitutes the species of 
 brute. Hence we say that the difference is the char- 
 acteristic idea which confines the generic idea to a 
 smaller number of individuals. 
 
 92. The individual idea is called singular, when it 
 refers to a determined individual, as Socrates ; and, 
 particular, when it represents an indetermined indivi 
 dual, as some philosopher. 
 
 93. The collective idea is that which expresses a 
 body of individuals, united by some bond ; as society, 
 nation, army, academy. 
 
 94. The absolute idea is that which does not of 
 necessity excite another idea ; as being. The relative 
 idea is that which of necessity does excite another idea, 
 as effect that of cause ; father, that of son j equal, that 
 of another equal ; greater, that of less. 
 
 95. The essential idea is that which is necessary for 
 the thing; the accidental, or modal, that which doet 
 
86 LOGIC. 
 
 not imply this necessity. A man without a rational 
 soul is not man : hence, the idea of rationality is essen- 
 tial to man. But a man can be learned or ignorant, 
 virtuous or vicious, handsome or ungainly, without 
 ceasing to be man ; consequently these ideas are acci- 
 dental or modal in the conception of man. 
 
 Section II. — Bales for Perceiving Well, 
 
 96. Perception can be on objects real or possible. 
 In th« case of real objects, the perfection of perception 
 consists in perceiving them such as they are in them- 
 selves. With regard to possible objects, the perfection 
 is found in perceiving them such as they ought to be, 
 according to the matter on which the thinker is en- 
 gaged, and the conditions to which it is subjected. 
 This will be better understood by an example : — 
 
 97. Take, for instance, a real circle, the wheel of a 
 machine. Here the perception will be perfect, if it 
 take in with exactitude the circular form of the wheel 
 such as it is, even with the imperfections of its con- 
 struction. If the circle of the wheel were not perfect, 
 conceiving it as perfect would be an imperfection 
 of perception. If we speak of a possible circle, then 
 tlie perfection of perception consists in putting into 
 !!ie idea of circle every thing that is necessary for its 
 essence. 
 
 98. It is to be inferred from these considerations, first, 
 that the knowledge of reality is so much the morc^ per- 
 fect, the more closely it is approached ; and, secondly, 
 that the knowledge of things in the order of possibility 
 is all the greater, the better are fulfilled the established 
 conditions in the respective cases. 
 
PERCEPTION. 87 
 
 To perceive well, the folloTving rules should be 
 observed : — 
 
 I. 
 
 99. Attend to the object before you, giving no 
 consideration to any other thing. 
 
 n. 
 
 100. If the idea comes by the medium of words, fix 
 the sense of the words with all exactitude. 
 
 Confusion in words produces confusion in ideas. 
 Innumerable disputes would be resolved with more 
 satisfaction, or they would be avoided altogether, if 
 more care were used in fixing the true sense of terms. 
 
 m. 
 
 101. The understanding should be assisted by the 
 faculties best calculated to place it in relation with the 
 object we have to perceive. 
 
 In literature and the fine arts we could not perceive 
 weB. if we did net make good use of imagination and 
 sentiment. 
 
 !V. 
 
 102. When perception is employed on a single ob- 
 ject, it is advisable to isolate it from every thing else, 
 80 as to contemplate the idea purely alone. 
 
 V. 
 
 103. If the object is compound, il is necessary tp 
 analyze it, and to form a clear and exact idea of itar 
 various parts. 
 
 VI. 
 
 104. In the examination of parts, sight should never 
 be lost of the compound thing to which they belong. 
 
 A bad idea would be formed of the parts of a watch, 
 
88 LOGIC. 
 
 if Ibey were considered without paying any regard to 
 tlie places intended for them in the article, or to the 
 functions they exercise in it. 
 
 VII. 
 
 105. To be certain that perception is tnie, it would 
 be well to prove it by expressing interiorly with wor^s 
 the thing perceived. 
 
 Very often we form the illusion of having properly 
 perceived an object, although we are unable to express 
 it with clearness. In general, want of propriety in 
 words indicates a confusion in ideas. 
 
 There can be more or less culture in language 
 according to one's education, and more or less propriety, 
 according to the greater or less knowledge of the idiom ; 
 but it is certain that, when the knowledge of a thing is 
 clear and exact, the expression will manifest it in an 
 unequivocal way. " I understand it, but I do not know 
 how to explain it," is a great refuge for vanity and 
 ignorance. 
 
 VIII. 
 
 106. We should avoid precipitation with the greatest 
 care. 
 
 Precipitation often arises from perceptive facility it- 
 self, — a thing which has the power of deceiving its owner, 
 making him believe he has seen a thing to the foundation, 
 wb^.n he has not yet passed the surface. But, very 
 trequently, we precipitate ourselves, at one time, by 
 natural impatience, at another through haste to get 
 quickly emancipated from an employment, and again 
 by a puerile vanity, which hinders us from commencing 
 Knew, lest we should discredit our own penetration. 
 
 IX. 
 
 1C7. The act of perception should be neither pre^ 
 
PERCEPTION. 39 
 
 ceded nor accompanied by any thing which could 
 make us form a mistaken conception. 
 
 In books and things, we find every thing as we wish 
 (o find it : preoccupation and the passions are, to the 
 understanding, what a stained glass is to the eyes . 
 we see every thing in the color of the glass. 
 
 X. 
 
 108. It is good to consider a thing at different times, 
 under various dispositions of the mind, in order to be 
 certain that we have perceived it well. 
 
 This is an excellent kind of counter-proof for discover- 
 ing truth. — At night, moved by conversation or other 
 circumstances, we see an object in one way ; but, we 
 retire, and we sleep tranquilly ; with rest the body is 
 relaxed, the passions are calmed, the mind is relieved ; 
 at waking we think the subject over afresh j and, at 
 once, the whole thing has a new appearance. 
 
 Illness, disgusts, inconveniency, food, the tempera- 
 ture — in a word, every thing which affects our body 
 directly or indirectly, also affects our perceptions ; 
 and, therefore, it is always necessary, in acts of per- 
 ception, to keep in view the disposition of mind and 
 person in whict we may be. 
 
 XI. 
 
 109. When perception is on objects that can be 
 submitted to experience, this touchstone should be 
 applied. 
 
 We have much inclination to convert our ideas into 
 facts. This is the spring of many extravagant systems 
 in the sciences, and of many equivocal judgments in 
 the ordinary course of life. Thought does not alter 
 facts which are independent of it, but impatience in- 
 duces us to give to things the form represented in our 
 thought. 
 
40 LOGIC. 
 
 Section III. — Expression of Ideas and of their Objects 
 
 110. The word with which we express a conceived 
 thing is called a term, or a vocable. To express objects 
 we must have ideas of them ; but it is to be noted 
 that words do not express ideas themselves, but the 
 things represented by ideas. In the w^ord sea, the idea 
 of the sea is not signified, but the sea itself. Thus we 
 Bay, the sea is agitated ; but we do not say that the idea 
 of the sea is agitated. 
 
 111. The common or universal term is that which 
 expresses a property belonging to many, as wise ; the 
 singular term is that which declares only one thing, 
 as Plato. 
 
 112. The collective term is that which announces a 
 body of beings, as nation, academy, congress. 
 
 113. The common term is divided into the univocal, 
 the equivocal, and the analogous. The univocal is 
 that which has the same significatitm for many, as maa. 
 The equivocal is that which has diverse significations, 
 as lion, which expresses an animal as well as a sign in 
 the heavens. The analogous is that which has a signifi- 
 cation in part identical and in part diverse, as sound; 
 which, always expressing a relation to health, is ap- 
 plied to the man who has health, to the food that con- 
 serveg it, to the advice which restores it. 
 
 114. To be brief, we observe that terms, although 
 they express things themselves, signifying them through 
 the medium of ideas, are, in the same manner as ideas, 
 susceptible of various divisions. Hence they are called 
 universal, generic, specific, individual, particular, 
 
PERCEPTION. 41 
 
 singular, collective, absolute, relative, abstract, con- 
 crete, etc., etc., according as they express ideas of each 
 respective class. 
 
 115. Ideas are expressed with words, and the use 
 of words is not external alone ; it is internal too : 
 before speaking to others we speak with ourselves ; 
 all of us experience that internal language with which 
 the mind gives an account to itself, of what it knows, 
 or feels. Ideas bind themselves with words; and 
 words are a kind of register to which "v\re entrust 
 the order, and the memory, of ideas. 
 
 116. Hence it follows that the care can never be 
 excessive which we bestow in fixing with propriety and 
 exactness the sense of words j not only of the words 
 which we employ with our fellowmen, but also of those 
 which we use with ourselves. It is difficult to under- 
 stand those who do not understand themselves. Not 
 understanding ourselves is a much more frequent thing 
 than we imagine. 
 
 117. Among words it is necessary to distinguish 
 the most important, those which are, as it were, the 
 pivot on which the question turns. In most matter? 
 there is some term which is specially influential, and 
 whose signification is the key for resolving all the dif- 
 ficulties they contain. It is known by expressing the 
 principal issue of the question ; and it occurs Rt each 
 etep of the dispute, or examination, entering as subject, 
 or predicate, of the proposition discussed. 
 
49 LOGIC. 
 
 AUXILIARY OPERATIONS FOR GOOD PERCEPTION. 
 
 Section I. — Definitions, 
 
 To perceive well, it is very important to define and 
 to divide well. 
 
 118. Definition is the explication of a thing. Its 
 nRme indicates its object : to define^ to mark the limits, 
 the ends. 
 
 "il9. Definition is of two kinds : one, the explication 
 of things ; the other, of the sense of words. The first ia 
 called real definition — definitio rei ; the second is called 
 nominal definition — definitio nominis. 
 
 120. Definition, to be good, should express and 
 explicate all that is in the thing defined, and nothing 
 more. Ally because, otherwise, it would be incomplete j 
 and nothing more^ because if it contains any thing more, 
 the defined thing would be confounded with things 
 distinct from it. 
 
 The following is a definition of the rectilinear tri- 
 angle : a superficies enclosed by three right lines. 
 Here, if the word right were left out, the definition 
 would be imperfect, because then it would not expreei 
 all that is contained in the idea of a rectilinear tri- 
 angle, and hence it would be equally applicable to 
 the mixtilinear and curvilinear triangles. And if, to 
 the same definition, we should add the word equal^ it 
 would be also imperfect, for in that case it would ex- 
 press rY>ore than is contained in the idea of rectilinear 
 triangles in general : and this would make the definition 
 applicable only to equilateral triangles. 
 
 It is a bad definition of man to say that he is a being 
 composed of body and soul : because, by not intimating 
 
PERCEPTIOlf. 48 
 
 tliat this soul is spiritual, we do not express all that is 
 contained in the nature of man ; and, again, if we 
 should say that man is a being composed of a body and 
 a virtuous soul, we would say more than belongs to the 
 nature of the thing defined ; and the definition would 
 not be applicable to man in general, but only to a 
 virtuous man. 
 
 121. To be certain that a definition is perfect, it 
 should be proved, applying it to the thing defined, 
 according to the following rule : 
 
 The definition should correspond to all the thing 
 defined and to nothing more. 
 
 It is a good definition of man to say that he is a 
 rational animal, because it is applicable to all men and 
 to nothing else but man. 
 
 To define him a living thing, is to define him badly, 
 because brutes and plants are living things, as well as 
 men. 
 
 To define him as an intellectual being is no better. 
 because the pure spirits are also intellectual beings. 
 
 To define him a virtuous rational animal is wrong, 
 for such a definition d^/es not embrace all men, but the 
 virtuous alone. 
 
 122. Definition is essential and descriptive. The 
 essential is that which explains the essence, or the 
 internal nature, of a thing. The descriptive is that 
 which treats of a thing, not by its essence, but by some 
 distinctive properties. If we knew the internal nature 
 9f the sun, we could give an essential definition of it 
 But as we do not, we must be satisfied with a descrip- 
 tive definition of it : for instance, it is the star A'hose 
 light constitutes what we call day. Here there is 
 enough to discriminate between the sun and all other 
 objects, but the definition is not essential 
 
44 Looic. 
 
 123. The small knowledge which we have of the 
 essence of objects restricts us much in essential defini- 
 tions ; and from this it follows that, in the majority of 
 cases, we should content ourselves with definitions of 
 the descriptive class. 
 
 124. Definitions given at the opening of questions, 
 should be sufficient to make known to us the point at 
 stake, and they should determine well the meaning of 
 the words employed. The perfect definition comes in 
 at the end of an operation ; because, as its office is to 
 explain, it must be the result of investigation. Defin- 
 ing a thing at the outset is equivalent to supposing 
 what is yet to be discovered, to confounding the seed 
 with the harvest. 
 
 125. With these observations it is easy to under- 
 stand the sense and the reason of the rules usually given 
 for defining well. 
 
 RULES FOR DEFINING. 
 I. 
 
 126. The definition should be clearer than ihe thing 
 defined. It is evident that, as its object is to explain, 
 it ought to clear up what it proceeds to explain. 
 
 II. 
 
 127. The thing defined should not enter into tho 
 definition. 
 
 1 28. When the thing defined enters into the definition, 
 no advance is made, because then in our act of explaining 
 
PERCEPTION. 45 
 
 we make use of the very thing that needs itself to be 
 explained. For instance : defining Migation by say- 
 ing that it is that which obliges us tc do, or to omit, a 
 certain thing, violates the rule ; for, if we are ignorant 
 of what obligation is, we are also ignorant of what it is 
 \o oblige. 
 
 m. 
 
 129. Definition should contain the proximate genus 
 and the ultimate diff'erence. 
 
 Defining man as a rational substance breaks this rule, 
 because the genus, substance, is not the immediate one, 
 while the genus, animal, is. 
 
 130. Some writers lay down that definition should be 
 brief; and, in truth, provided that the words are clear, 
 the fewer of them employed the better. But care should 
 be taken to avoid the rock, " Brevis esse labor Oy obscurus 
 ^0," — ^by love of brevity I make myself obscure. 
 
 131. Redundant words, if they express any thing 
 foreign to the thing defined, make the definition bad, 
 because they express more of the thing than it is ; 
 and if they only declare what the other terms declare, 
 they are useless, and, from this, they help to embarrass 
 when they do not confuse. 
 
 132. Let us terminate by observing, that in definitions 
 it is necessary to guard as much as possible against 
 metaphorical or figurative expressions in every sense 
 whatever. In cases of definition, the imagination is 
 much more frequently an obstacle than a good auxiliary : 
 it is calculated to sacrifice terseness to the gleam of a 
 comparison, or the ingeniousnesg Qf a contrast, 
 
46 LOGIC. 
 
 Section II. — Division, 
 
 133. The limited nature of our understanding hinderr 
 tti from embracing many things at one time. Henco 
 we employ a means for considering them separately. 
 And this is necessary not only when objects are really 
 separated, but also when they are umited, and, some- 
 times, even when they are identical. Even in simple 
 things we distinguish various aspects, after the manner 
 of parts. Hence, division is one of the most important 
 operations. 
 
 134. Division is the distribution of a whole into its 
 parts. 
 
 135. As are the parts, so should be the division. 
 When they are real, or exist in reality, and are separ- 
 able, the division should be real, or physical. When 
 the parts are not separable, but are properties inherent 
 in the subject, the division should be metaphysical. 
 When the parts are logical, or exist only in our 
 understanding, the division should be logical. 
 
 Man is really composed of two distinct and separable 
 things, body and spirit. If we divide man into these 
 two parts, we have a real division. In man there are 
 the two properties, — animal and rational ; but not two 
 subjects, because in man that which is animal is the 
 same as that which is rational; and, consequently, by 
 dividing man into what is animal and rational, we make 
 a metaphysical division. In the genus of animal are 
 contained men and brutes, or rational and irrational 
 beings. But here the word contaifij that is, the word 
 contain in relation with the genus of animal, does not 
 signify that there is in reality a being composed of these 
 two parts, or of these two properties ; that is, it does 
 not mean that there is a being, which, as a being, is at 
 
PERCEPTION. 47 
 
 one and the same time rational and irrational : that is 
 a contradiction ; it only means that the idea of animal 
 can belong to different species. Hence, these two 
 parts are found only in our understanding ; and so the 
 division of animal into rational and irrational gives a 
 logical division. 
 
 If we divide the rectilinear triangle into its three lines, 
 the division is real : because these lines are distinct and 
 separable parts. If we divide it into the two parts, the 
 enclosed figure and the three lines, we have a meta- 
 physical division : because, although these two properties 
 are constitutives of the triangle, they are not separable 
 in the same way that the enclosed figure is separable 
 from the three lines. Finally, saying that the triangle 
 is divided into the equilateral, the isosceles, and the 
 scalene, the division is logical ; for although these 
 qualities united do not exist, and cannot exist in any 
 triangle, we have still the general idea of triangle which 
 i« applicable? to the different species of the same genua 
 
 RULES OK :)IVISION. 
 
 1 
 
 136. In division all the pterts should be enumerated. 
 Dividing the human body into flesh and bones, or into 
 the head and trunk, is making an incomplete division, 
 for it omits other parts. 
 
 11. 
 
 137. In division, one part should not be contained in 
 aLv>ther. 
 
 Dividing the world into its various parts, counting 
 Europe among them, and then adding Spain, the divi 
 lion is defective, for Spain is already contained h 
 
48 LOGia 
 
 Europe. Were we dividing Europe into its parts, then 
 it would be proper to bring in Spain, 
 
 In like manner it is making a bad division of an 
 unimal being, to divide it into the sensitive and 
 rational ; for the sensitive being is already contained in 
 the animal being. 
 
 III. 
 
 138. The parts of a division ought to be of one and 
 the same species. 
 
 The division of the human body into its members, aa 
 into the head, the trunk, the arms, etc., etc., should not 
 be mixed up with the division into the various species 
 of parts, as the flesh, the bones, the blood, and so on. 
 
 IV. 
 
 139. In division, the natural order of things, and of 
 ideas, should be followed. 
 
 It would be making a bad division of Europe to jump 
 from country to country, in a way really at variance 
 with the order in which the nations lie in regard to 
 each other. 
 
 Dividing a living thing into rational and irrational, 
 is out of rule ; for the idea of sensibility is passed over. 
 Hence, a living thing is properly divided into sensitive 
 and insensitive ; and, therefore, the living thing, or 
 animal, is correctly subdivided into rational and irra- 
 tionaL 
 
 ] 40. Too many subdivisions should not be made. 
 
 Doing this, far from clearing up, confuses. To form 
 a just idea of things, it is not necessary to grind theat 
 to »K)wder. 
 
JUDGMENT AND PROPOSITION. 41 
 
 CHAi^TER IV 
 
 JUDGMENT AND PROPOSITION. 
 
 3kiJTI0N [. — Definition of Judgment and of Proposition 
 
 141. A JUDGMENT is the intellectual act hy which we 
 affirm or deny one thing of another. In the first case, 
 the judgment is called affirmative ; in the second, 
 negative. The *"un shines, — is an affirmative judg- 
 ment ; the moon has no light of its own, — is a negative 
 judgment. 
 
 142. The expression of a judgment in words is called 
 a proposition. The internal act with which I affirm 
 that the day is beautiful, is called a judgment; the 
 words in which I express it, form a proposition. The 
 explanation of the various classes of judgments and of 
 their rules, is also the explanation of propositions. 
 Hence, what is here said of propositions will be under- 
 stood as said of judgments, and conversely. 
 
 143. In every judgment there is relation of one thing 
 to another: that which affirms, or denies, with that of 
 which there is affirmation or negation. 
 
 That ef which we affirm or deny something, is calhul 
 the subject ; and that which we affirm or deny, ia 
 known as the predicate, or attribute. 
 
 The expression of the relation of the predicate with 
 the sul)ject, is called the copula ; and the copula is con- 
 tained in the verb to &e, expressed or understood ; — 
 
 3 
 
50 LOGIC. 
 
 Treason is a crime: treason ia the s abject^ crime^ 
 trb« predicate ; is, the copula. 
 
 1 44. In many propositions the verb to he is not ex- 
 nrcssed, but it is always understood. Crassus has great 
 wealth ; Cicero excels in eloquence ; Caesar distin- 
 guishes himself by his political ability : these proposi 
 tions are equivalent to the following : Crassus is very 
 nch ; Cicero is excellent in eloquence ; Caisar is an able 
 politician. 
 
 And the subject and predicate are not always found 
 expressed. I exist, — is equivalent to this : I am ex- 
 isting. 
 
 Section II. — Division of Propositions, 
 
 145. Propositions may be considered in themselves, 
 and in their relations with each other. Let us consider 
 them under each aspect. 
 
 1 46. By reason of the copula, propositions are divided 
 into affirmative and negative. This is called their 
 quality. The affirmative is that whijh affirms; the 
 negative, that which denies. 
 
 147. To make a proposition negative, the negation 
 must affect the copula : poverty is not a disgrace. But. 
 if the negation does not affect the eopula^ the proposi- 
 tion is not negative. The law does not command to da 
 this, is a negative proposition. The law commands 
 not to do this, is an affirmative proposition. The dil- 
 ference arises from the difference of place which the 
 fi**gation occupies. 
 
 148. By reason of the subject, propositions are 
 divided into universal, particular, indefinite, and singu- 
 
JUDGMENT AXD PROPOSITION. 51 
 
 lar, according as the subject is universal, particular, 
 indolinite, or singulai. This is called their qi w ilifejy .^i/M/y/Til 
 
 149. Every tree is vegetable. The proposition ia 
 uRivftisal: because its subject, as the term evvty 
 indicates, is universal. 
 
 150. Some bodies are elastic. The proposition is 
 particular: because the subject is confined to the limiia 
 in the word some, 
 
 151. Germans are speculative. The proposition is 
 indefinite : because the subject, Germans, is not 
 determined, for it does not express either all or some. 
 
 152. Newton is an eminent mathematician. The 
 proposition is singular : because the subject is so. To 
 have a proposition singular, it is not necessary for tho 
 subject to be a proper name ; a pronoun effects this 
 purpose. For example : if, in regard to a piece of 
 metal which I have in my hand, I say, this metal is 
 silver, the proposition is singular, through the pronoun 
 this. And, in place of a pronoun, some characteristic 
 property may be used. For instance : the man who 
 conducted the building of the Escurial, was an 
 eminent architect. The engineer who constructed the 
 liOndon tunnel, is worthy of a statue. 
 
 153. Some divide the universal proposition into 
 distributive and collective. The distributive is that 
 In which the predicate agrees separately with all, that 
 is, with each one of the subjects. All Spaniards are 
 Europeans. This is a universal distributive proposition, 
 because being a European, is a thing that belongs to 
 each Spaniard in particular. The Spaniards are four- 
 keen millions : this is collective, because each Spaniard* 
 
52 ix)Gic. 
 
 is not fourteen millions, but all Spaniards, taken 
 together, are. But collective propositions, it will be 
 seen, cannot be reduced to a species of uniyersals j for 
 there are collective particular, collective indefinite, and 
 collective singular, propositions. 
 
 For example, if we say, the expenses of the state 
 are ten millions — the proposition is collective, because 
 it is unders^ccd of the expenses united-^ and it is singu- 
 lar, becausrj 't refers to a determined collection. 
 
 The expenses of any state whatever should come 
 within the twelfth part of the rents of the country. 
 The proposition is collective, because it speaks of aU 
 the collections of expenses of all countries. 
 
 The expenses of some states do not exceed two 
 hundred millions. The proposition is collective, for 
 the reason assigned above ; and it is particular, be- 
 cause it speaks only of some collections of expenses, 
 for it speaks only of some states. 
 
 The expenses of states are excessive. The proposi- 
 tion is collective, for the same reason ; and it is in- 
 definite, for it does not say whether the excessiveness 
 is in all states, or in some. 
 
 Hence, it is clear that collective propositions are of 
 such a nature that they cannot be considered a« a 
 species of universals. Their distinctive character is in 
 the mode in which the subject is taken. And it is 
 also evident, that the collective term should not be 
 classified among common, or universal terms. 
 
 Section III. — Bules on the Extension oj the Subject, 
 
 154. The'*^'5 is no difficulty as to the extension of the 
 subject ii. »ii.rersal, particular, or singular propositions: 
 for it is plain that, in universals, all are spoken of 
 without exception ; that, in particulars, some are 
 Bpoken of indeterminately ; and that, in singulars, the 
 assertion is of one or many, but without determination. 
 
JUDGMENT AND PROPOSITION. 53 
 
 But it is not the same thing in indefinite propositions, 
 Ai in this — the Grermans are speculative : here it is a 
 qnestion whether it is all, or some, that are meant. 
 This is a very important point, because the proposition 
 w tru<», or false, according to its extension. 
 
 Th<^ following two rules are a key to indefinite pro* 
 j'Ositions : — 
 
 RULES ON INDEFINITE PROPOSITIONS. 
 
 155. In matters belonging to the essence of things, 
 or to their necessary properties, the indefinite proposi- 
 tion is equivalent to a universal. 
 
 The diameters of a circle are equal : this is under- 
 stood of all diameters. The orbits of the planets are 
 elliptical: this is understood of all orbits of planets. 
 It is evident that the proposition will be more or less 
 rigorously universal, according as the necessity ex- 
 pressed is intrinsic or natural. In the examples 
 given, the universality of the first is necessarily 
 absolute, without possible exception, for it is founded 
 in the essence of things ; that of the second is not 
 universal with perfect rigor, because it rests only on 
 a natural law known by observation. 
 
 n. 
 
 156. When the proposition does not speak either of 
 the essence of things, or of their necessary la'ws, the 
 universality is moral; that is, it embraces the greater 
 part of things. Thus, in the example on the Germans, 
 it is not understood that all the Germans are speculative : 
 what is understood is, that this is the character of that 
 nation, and that, hence, there are many who have it. 
 Moral universality is more or less ample, according Ko 
 
54 Loaic. 
 
 the nature of the matter considered. And here no rule 
 can be fixed, excepting that judgment should be pru- 
 dently made according to circumstances. 
 
 157. It is sometimes said that, in contingent matters, 
 the indefinite proposition is equivalent to the particular. 
 This is not exact. In every indefinite proposition there 
 is a certain universality. Thus, in a country where 
 the greater part of the inhabitants had red hair, it 
 could be indefinitely said that they had black hair, 
 provided there were some exceptions in this sense. 
 
 Section IV. — Bules on the Extension of the Predicate, 
 
 158. We have seen that the subject of the proposi- 
 tion can be taken in diff'erent ways (Sections II and 
 III) ; let us see now how it is with the predicate, or 
 attribute. 
 
 In this part of logic, some things difficult to be under- 
 stood are encountered. But this arises from not 
 sufficiently observing that the dialectical rules are only 
 a brief and precise formula of common, and even vul- 
 gar, ideas. 
 
 159. The manner in which the term is taken in a 
 proposition is called, in scholastic terms, the suppo- 
 sition. The application of a term to a greater or less 
 number of subjects, is called its extension. To say that 
 a term supposes universally, is the same as saying that 
 it has a universal sense, or extension. 
 
 160. Every man is a rational being. Here the sub- 
 ject is taken universally. But how is the predicate 
 taken ? Is it understood that the word rational is taken 
 universally ? 
 
 It is evident that each man is not all rational beings, 
 
JUDGMENT AND PROPOSITION. 56 
 
 birt some rational being ; and, therefore, the predicate!, 
 rational, is taken particularly. 
 
 These considerations give the following rules for 
 predicates : — 
 
 RULES FOR PREDICATES. 
 I. 
 
 In every affirmative proposition, the predicate, or 
 
 attribute, supposes particularly. 
 
 161. No metal is a living thing. In what extension 
 should the predicate be taken ? It is clear that the 
 quality of being a living thing, m totOy is denied of every 
 kind of metal; so that the proposition would not be true 
 if there were any kind of metal whatever which could be 
 called a living thing. And, therefore, the predicate is 
 taken universally. This is expressed in another rule : — 
 
 II. 
 
 In every negative proposition the predicate supposes ^ 
 universally. 
 
 162. The comprehension of a term means the number 
 of the properties which it signifies : for instance : those 
 of the term, animal, are life and sensitiveness j and 
 those of man, rational animal. The difference between 
 extension and comprehension is in this, that extension 
 refers to the subjects to which the term corresponds; 
 and comprehension to the properties which it declares. 
 
 163. Man is an animal. In this proposition all the 
 properties of the predicate animal are affirmed of man, 
 and it would not be a true proposition if man 
 lacked any one of these properties. Hence it is that 
 plants, although they have one of these properties. 
 
66 liOGIG. 
 
 which is that they have life^ Oi* are living things^ 
 cannot be called animals, for they have no sensibility 
 And from this we establish the subjoined rule : — 
 
 III. 
 In affirmative propositions, the predicate is applied 
 to the subject in all its comprehension. 
 
 164. Plants are not metal. Here metal, in all its 
 extent, is denied of plants. But all the properties 
 oontained in the idea of metal, are not denied of plants j 
 as for example, that they are bodies, that they are 
 Tisible; and so on. From this we have another rule : — 
 
 IV., 
 
 In negative propositions, the predicate is not denied 
 in all its comprehension of the subject. 
 
 165. Summarising these four rules, we say that, in 
 affirmative propositions, the predicate is taken in all its 
 comprehension, but not in all its extension ; and that, 
 in negative propositions, it is taken in all its extension, 
 but not in all its comprehension. 
 
 Section V. — The Conversion of Propositions. 
 
 166. The conversion of propositions is the transposi- 
 tion of their terms, putting the subject in the place of 
 the predicate, and the predicate in the place of the sub- 
 ject. There are three kinds of conversion, the simple^ 
 the per accidens, and that by contraposition. In the 
 first, nothing of the terms is altered but their place ; in 
 the second, the quantity of the terms is changed ; in 
 the third, they are taken in a negative sense, in con- 
 traposition to that they heid before, or, according to the 
 expression of the schools, they are made infinite : for in 
 stance, if the term were body, it is said to be not body. 
 
JUDGMENT AND PROPOSITION. 57 
 
 167. Dialecticians have a way of converting proposi- 
 iions, 01 rather of so making the transposition that, the 
 primitive proposition being given, a new legitimate one 
 should be the result. For this operation they mark the 
 quantity of propositions with letters, designating a 
 universal affimative with Ay a universal negative with 
 Ej the particular affirmative with /, and the particular 
 negative with 0. This mode is expressed in the fol 
 lowing verses : 
 
 Asserit A, negat E; verum generaliter ambo. 
 Asserit /, negat 0; sed particulariter ambo. 
 
 The rules for the conversion of propositions are con 
 veyed in this formula : 
 
 B, /simpiiciter convertiter; B, A per accid. 
 0, A per contra : sic fit conversio tota. 
 
 This means that the universal negative proposition 
 designated by E, and the particular affirmative desig- 
 nated by /, are simply converted ; that the universal 
 negative E, and the universal affirmative Aj are con- 
 verted per accidens ; and that the particular negative 
 0, and the universal affirmative Aj are converted by 
 contraposition. This will be better understood by ex- 
 amples : — 
 
 168. E Simpiiciter : — No metal is a living thing. — No 
 living thing is metal. — The simple conversion is legiti- 
 mate ; because, as in negative propositions, the predi- 
 cate is taken universally, all living thing (all that has 
 life in it) is denied of all metal ; and, consequently, all 
 that is metal can be denied of all, that is. of every living 
 thing. 
 
 169. I Simpiiciter : — Some living thing is an animal. 
 Some animal is a living thing. — The simple conversion 
 is legitimate j for, in both cases, the predicate is taken 
 particular^. Thus, the first proposition is equivalent 
 
68 LOGIC. 
 
 to this : some living thing is some animal j from which, 
 evidently, results the second, — some animal is a living 
 thing, that is, some living thing. 
 
 1 70. Eper Accidens : — ^No European is an American. 
 Some American is not a European. — The conversion 
 is legitimate, because, if we hold (166) that no American 
 is a European, with greater reason may we hold that 
 some American is not a European. 
 
 171. A per Accidens : — Every planet is a body. Some 
 body is a planet. 
 
 As in the first, the predicate taken in particular 
 applies to all the subjects ; so the same predicate in 
 particular can be subject for the predicate planet ; but 
 it would not be a legitimate conversion to say, every 
 body is a planet. 
 
 172. per Contrapositionem : — This conversion, 
 although legitimate, is strange, and of little or no use : 
 and we give it only to complete the explanation of these 
 formulas. Some body is not a planet. Some no planet 
 is a body ; or, rather, some no planet is not no body. 
 
 Some body is denied to be every planet ; but from 
 this it does not follow that the predicate body can be 
 denied of every planet, or even of some planet. Hence, 
 to verify the conversion, it is necessary to recur to the 
 foreign idea of making a term negative, thus : Some no 
 planet is a body j or, as in this : Some no planet is not 
 110 body. 
 
 Section VI. — The Opposition oj Propositions, 
 
 1 74. The opposition of propositions consists in this, 
 that, having the same subjects and predicates with equal, 
 or different, quantity, one is affirmative, and the other 
 negative. 
 
JUDGMENT AND PROPOSITION. 59 
 
 175. There are different kinds of opposition, accord- 
 ing to which propositions take different names ; for 
 instance, contradictories, contraries, subcontraries, and 
 subalterns. Propositions thus named are generally ex- 
 hibited in the following scheme, giving to the 1 »ur 
 letters Aj E^ /, 0, the same signification conferrep <>u 
 them above (165). 
 
 A CONTRARIES. E 
 
 ^ ^^^ ^n S 
 
 I SUBCONTRARIES. 
 
 176. The interpretation is : — 
 
 A contradictory of : — The universal affirmative and 
 the particular negative are contradictories. All metal 
 is body, some metal is not body. In the first it is 
 affirmed of all (every) metal, that it is (a) body ; in the 
 second, it is denied of some metal that it is body. 
 Hence, they contradict themselves. 
 
 E contradictory of I: — The universal negative and 
 the particular affirmative are contradictories. No 
 planet is a comet ; some planet is a comet. In the first 
 it is denied of all planets that any one of them is a 
 comet ; but in the second it is asserted that some planet 
 is a comet. This is the contradiction. 
 
 It results from this that the contradictory propositions 
 are those in which what one affirms the other denies. 
 This is rigorous opposition. The other kinds of opposi- 
 tion deserve this term only in a broad sense ; in some 
 cases there is not even the appearance of opposition. 
 
^ LOGIC. 
 
 177.-4 contrary ofE: — The universal affiimative and 
 the universal negative are contraries. All Africans 
 are black ; no African is black. 
 
 In this there is no contradiction. The two proposi- 
 tions are false. And to make them false, it is enough 
 that some Africans are black, and others not. 
 
 178. I subcontrary of 0: — The particular affirmative 
 and the particular negative are sub contraries. Some 
 living thing is sensitive ; some living being is not sensi- 
 tive. Both are true ; because plants are living things, 
 and yet have no sensibility, and animals are living and 
 sensitive things, or beings. 
 
 179. I subaltern of A: — The particular affirmative 
 is the subaltern of the universal affirmative. All wise 
 men have been studious ; some wise man has been 
 studious. 
 
 There is no opposition between these propositions j 
 on the contrary, there is a connection, for the second is 
 inferred from the first. 
 
 180. subaltern ofE: — The particular negative is the 
 subaltern of the universal negative. No vicious per- 
 son is esteemed j some vicious person is not esteemed. 
 The observation made in the anterior case is applicable 
 here. 
 
 RULES ON THE OPPOSITION OF PROPOSITIONS. 
 I. 
 
 181. Two contradictory propositions cannot be both 
 true o: false : if one is true, the other is false. The 
 reason is : it is impossible for a thing to be in being 
 and out of being at one and the same time. 
 
JUDGMENT AND PROPOSITIOir. 61 
 
 n. 
 
 182. In subaltern propositions, if the universal ii 
 
 in ae, the particular is true ; but not conversely. 
 
 If all virtue is laudable, it is clear that some virtu© 
 is laudable. If no vicious person is estimable, it fol 
 lows that some vicious person is not estimable. But, 
 from the fact that some body is a planet, it does not 
 follow that all bodies are planets: and from having 
 some learned man not virtuous, it cannot be inferred 
 that no learned man is virtuous. 
 
 m. 
 
 183. The contraries can be both false, but both of 
 them cannot be true. 
 
 Ail Europeans have visited America j no European 
 has visited America. Both are false. That both can- 
 not be true is thus shown : the universal affirmative, if 
 tFue, makes the particular affirmative true (182). If, 
 then, the universal negative were also true, there would 
 be two contradictory truths, which is impossible. 
 
 IV. 
 
 184. The subcontraries can be both true, but not 
 false. 
 
 Some African is black ; some African is not black. 
 Both are true. 
 
 If both the subcontraries were false, the falsity of the 
 particular affirmative would make true its contradic- 
 tory, the universal negative ; and the falsity of the 
 particular negative would make true the universal 
 affirmative. This would give us two contradictory 
 truths, which is impoBsible. 
 
63 Looic. 
 
 Section VII. — Equivalence of Propositions, 
 
 185. Propositions are equivalent when they have 
 the same value, or express the same thing. 
 
 186. The contradictories are made equivalent by 
 putting a negation to the subject of either of them : — 
 
 Every man is wise ; some man is not wise. Thes« 
 are contradictory. But they become equivalent by the 
 use of the negative particle : not every man is Wise j 
 and, in the second case, no some man is not wise. But 
 the first form is the most common and natural. 
 
 187. The contraries are made equivalent, by )/ufcting 
 the negation after the subject of one of them: — 
 
 All body is metal ; the contrary of this, — ^no Dody is 
 metal, — is equivalent to saying ; aU body is not metal. 
 The second is also made equivalent to the first hy say- 
 ing, no body is not metal. 
 
 188. In these examples the negation is placed 
 immediately before the predicate. Sometimes it is 
 placed between the subject and the copula, but this 
 form is not so clear. 
 
 Section Vin. — Compound Propositions, 
 
 189. Propositions are simple and compound. The 
 simple are those which express the relation of one 
 single predicate to one single subject. We have con- 
 yidered them in the preceding sections. The compound 
 are those which contain more than one subject or than 
 one predicate. In every compound proposition, various 
 simple ones are contained. The compound are of many 
 kinds; but, as we shall see, all are not compound in 
 the same sense, and some can he reduced to simples. 
 
JUDGMENT AND PROPOSITION. 6$ 
 
 COPUI.ATIVE PROPOSITIONS. 
 
 190. The copulative proposition expresses the con" 
 nection of various affirmations or negations. It haa 
 three forms : when it announces one single subject with 
 many predicates, — one single predicate with many 
 subject, — and many subjects and many predicates. 
 
 Anicetus is virtuous and wise, is equivalent to these 
 two : Anicetus is virtuous, Anicetus is wise. 
 
 Anicetus is neither virtuous nor wise, is equivalent 
 to these two : Anicetus is not virtuous j Anicetus is not 
 wise. 
 
 Peter and Anthony are rich, is equivalent to these 
 two : Peter is rich ; Anthony is rich. Peter and 
 Anthony are not bad, is equivalent to these two : Peter 
 is not bad ; Anthony is not bad. 
 
 Peter and Anthony are neither studious nor edu- 
 cated, is equivalent to these four : Peter is not studious; 
 Peter is not educated ; Anthony is not studious j 
 Anthony is not educated. 
 
 Rule on Copulative Propositions.- 
 
 191. To have the copulative proposition true, all the 
 simple ones into which it can be decomposed must be 
 true. 
 
 IL— DISJUNCTIVE PROPOSITIONS. 
 
 192. The disjunctive proposition is that which affirms 
 one fact of various things, by implicitly denying the 
 existence of a middle or third thing between them. 
 
 Actions are either good or bad : this is equivalent to 
 saying, that there is no action which does not belong to 
 one of these classes. If a middle, or third kind of 
 actions, indifferent actions, for instance, be supposed, 
 the proposition is false. This metal is either gold or 
 silver The proposition is true, provided the metal is 
 
64 Loaic. 
 
 not lean, or copper, or any other kind of metal, but 
 either gold or silver : otherwise it is not true. 
 
 193. If the disjunctive proposition be properly 
 examined, it will be found to be equivalent to the 
 enumeration of the classes of things to which an object 
 can belong. This plate is of iron, of lead, of copper, 
 or of bronze : this is equivalent to saying : the classes 
 of metal of which this plate can be formed are the four 
 mentioned ones. The matter should belong to one of 
 them. 
 
 194. This observation is confirmed by common sense. 
 All would understand the proposition to be false, pro- 
 vided any other class of metal could be introduced, or 
 if some circumstance indicated that some one of the 
 mentioned metals were not present. 
 
 195. This shows that the disjunctive proposition does 
 not contain various affirmations or negations, but that 
 it is the expression of a simple judgment, for all simple 
 judgments are embraced in this disjunctive formula : — 
 
 To such a subject belongs this, or that, or the other 
 predicate. 
 
 196. Disjunctive propositions, therefore, cannot be 
 called compound in the sense of copulatives, for they 
 do not, like the latter, embrace various simple proposi- 
 lions expressive of so many other judgments (190). 
 
 Rule on Disjunctive Propositions. 
 
 197. To have the disjunctive proposition true, no 
 third or middle object can be introduced between the 
 members of the disjunction. 
 
JT7DGMENT AND PROPOSITION. 66 
 
 m.— CONDITIONAL PROPOSITIONS. 
 
 198. The conditional proposition is that which affirms, 
 or denies, one thing under the condition of another. 
 If the atmosphere is warm, the mercury will rise in 
 the thermometer. Here there is affirmed neither the 
 warmth of the atmosphere, nor the ascent of the mer- 
 cury : what is affirmed is the relation of the ascent 
 with heat. 
 
 199. Reflection will show that the conditional pro- 
 position is improperly classed among the compounds. 
 Strictly speaking, it is simple ; for, that which is 
 affirmed in it, is the relation of one thing with respect 
 to another. Thus the preceding proposition can be 
 expressed in this form : tlie rising of the mercury 
 depends on the heat of the atmosphere j or, in this one : 
 the heat of the atmosphere causes the ascent of the 
 thermometer. 
 
 200. Conditional negative propositions confirm this 
 observation. If it does not rain, there will be no har- 
 vest. In this proposition we express the necessarv 
 dependence of the harvest on the rain. Therefore, 
 this proposition is no more than a simple one : it 
 has one sole subject — harvest ; and one sole predicate 
 — dependence on rain. 
 
 201. In conditional propositions the part in which 
 the condition is, is called the antecedent ; and the con 
 ditional is called the consequence. If it rains, there 
 will be a harvest. If it rains^ is the antecedent j there 
 wiU he a harvest^ is the consequence. 
 
 Rule on Conditional Projpositions, 
 
 202. For these propositions to be true, it is necessary 
 
56 Loaic. 
 
 that, the antecedent being given, the consequence shall 
 follow it, for it is the consequence alone that affirms. 
 
 IV. CAUSAL, EXCLUSIVE, EXCEPTIVE, RESTRICTIVE, 
 
 REDUPLICATIVE, PRINCIPAL, AND INCIDENTAL 
 PROPOSITIONS. 
 
 203. There are causal, exclusive, exceptive, re 
 strictive, reduplicative, principal, and incidental pro 
 positions. Their names indicate their nature. 
 
 204. Causals are those which express the cause by 
 which the predicate belongs to the subject. They are 
 of various kinds, according as they signify different 
 species of causality. Caesar crossed the Rubicon 
 through the provocations of his enemies : here there is 
 a moral impulsive cause. Caesar crossed the Rubicon, 
 in order to control the state : here is a final cause. 
 Caesar defeated Pompey by the superiority of the troops 
 with which he fought in the Gauls : this gives us an 
 efficient cause. Caesar defeated Pompey through 
 Pompey^s want of foresight : this shows a preparatory 
 cause. 
 
 205. It is to be noted that in each of these examples 
 there are two propositions : one which affirms a fact ; 
 and one which gives the cause of it. It is easy to 
 decompose them into others — as the followi^.g : Caesar 
 was conqueror; the cause of Caesar's viecory was the 
 Buperiority of his troops. It is easy to see that these 
 propositions are reduced to copulatives (190). 
 
 206. There are causal propositions in which the 
 fact is not expressly affirmed, its cause alone being 
 given, in the supposition that the fact has been or wiU 
 be verified. For example : Rome would have been 
 •aved, if its ancient customs had been preserved. 
 
JUDGMENT AND PROPOSITION. 67 
 
 But causal propositions are reducible to the class 
 of conditionals in which there is affirmed only the 
 dependence of one thing with respect to another. 
 Thus the preceding proposition is equivalent to this: 
 If Rome had preserved its ancient customs, it would 
 have been saved. 
 
 207. Exclusive propositions are those which affirm 
 something, while excluding something else. In some the 
 exclusion touches the subject, in others the predicate : — 
 
 The young only are agile j which can be decomposed 
 into the following : the young are agile ; and those 
 who are not young, are not agile. Here it is the sub- 
 ject that is concerned. Archimedes is only a mathe- 
 matician ; equivalent to these : Archimedes is a 
 mathematician ; Archimedes does not know the other 
 sciences. The exclusion here touches the predicate. 
 
 208. This shows that exclusive propositions are equi- 
 valent in some way to copulatives, for they contain 
 two simples, one of which is affirmative, and the other 
 negative : — 
 
 209. The exceptive propositions affirm, or deny, by 
 excepting. 
 
 All the soldiers, excepting one, are obedient j equi- 
 valent to these two : one soldier is not obedient, and all 
 A\ i rest are obedient. Here the exception affects the 
 subject. — This soldier has all the military qualifications 
 excepting obedience ; which is equivalent to the 
 following : this soldier has not obedience, and, he has all 
 the other military qualifications. In this example the 
 exception affects the predicate. 
 
 210. It is evident that exceptive propositions include 
 two propositions, one positive and one negative. And 
 
as LOGIC. 
 
 hence the remarks made on exclusives (207) are appli- 
 cable to them. 
 
 211. Kestrictive propositions are those which affirm^ 
 or deny, the predicate of the subject, bringing in 
 Another property of the same subject : — 
 
 The magistrate, as judge, has nothing to do with 
 the recommendations of friends. The magistrate, as a 
 man, compassionates criminals. 
 
 These propositions are decomposed into two : the 
 magistrate does not give attention to the recommenda- 
 tions of friends ; when the magistrate administers 
 justice, he is not guided by the recommendations of 
 friends. 
 
 Here it is clear that, in restrictive propositions, there 
 is a certain limitation of the predicate to another pro- 
 perty of the subject. 
 
 212. Reduplicative propositions are those in which 
 the predicate is applied to the subject, in a way limited 
 to the property expressed by the name of the subject :— 
 The soldier, as a soldier, has no will but that of his chief. 
 
 213. The principal proposition is that which contains 
 the subject and the predicate, and an incident which 
 exj lains some property of either the one or the other. 
 The soldiers of Caesar that won at Pharsalia were 
 valiant. The principal is — the soldiers were valiant ; the 
 incident — that they won at Pharsalia. Hannibal con- 
 quered the Romans who waited for him at Cannae. In 
 this the incident affects the predicate. 
 
 214. Reflection will discover that here there are not 
 two propositions, but only complex terms ; for the inci- 
 dents are only parts which complete the sense of the 
 predicate^ or subject. 
 
JUDQMENl AND PROPOSITION. §§ 
 
 Section IX. — The False Supposition, 
 
 215. Propositions which falsely suppose the existence 
 1 1 a suVject are called de subjedo non supponenk. For 
 example : Centaurs are terrible creatures. Here it is 
 supposed that centaurs, which are fabulous monsters, 
 really exist. The circle described by Saturn is greater 
 than that of Mars : this also is a proposition de subjec- 
 H non supponentCj because it supposes that the orbits 
 of the planets are circular, whereas they are elliptical. 
 Prodigality is the most laudable vice: this is another 
 instance, for it supposes that there is some laudable 
 vice, while such is not the case. 
 
 216. When a proposition is called de suhjecto non 
 supponente, the meaning is that it conveys a falsity in 
 the subject. But the false supposition can also enter 
 the predicate. The Isthmus of Suez is greater than the 
 one between England and France : the supposition is 
 false ; for it supposes that England is united to France 
 by an isthmus, which is not the truth. 
 
 The false supposition can find its way into compound 
 propositions. It is easy to give examples illustrative 
 of this. 
 
 217. In the schools, when a conflict is made with 
 this kind of proposition, nego suppositum is the usual 
 answer. 
 
 Section X. — The Order of Terms. 
 
 218. The logical order of terms in propositions is the 
 following : the subject, the copula, the predicate, or attri- 
 bute. But the logical order is not always the most natural, 
 because, following the mode in which objects affect us, 
 we express in distinct order the ideas which represent 
 them, ^xterity in the transpositipn of words is one of 
 
70 LOGIC. 
 
 the resources of poets and orators. A word highly for- 
 cible and impassioned in one place, is languid and cold 
 in another. But this is a point that does not belong to 
 
 Logic. 
 
 219. All propositions, simple and compound, whav- 
 ever may be their form, and the order of tlie collocation 
 of their terms, can be reduced to one or more simple 
 ones, in which the terms can be placed in rigorous logical 
 order. To do this in simple propositions, it is enough to 
 discover what is the subject, or the thing of which there 
 is affirmation or negation ; it is done in compound pro- 
 positions by finding out the component parts. Pre- 
 ceding examples illustrate how this decomposing is done. 
 
 Section XL — Truth, Certitude, Opinion, Doubt 
 
 220. Truth in the understanding, or formal truth, is 
 the conformity of the understanding with the thing (2). 
 But it is to be noted that formal truth, properly speak- 
 ing, is not in perception, but in judgment Because, 
 as in perception we neither affirm nor deny, there can 
 be neither conformity nor opposition between the in- 
 tellectual act and the object. If we conceive a giant 
 of a hundred yards in stature, without affirming that 
 such a being exists, we have a representation to which 
 nothing corresponds ; and here there is no error. But 
 if we interiorly affirm that a giant a hundred yards in 
 stature exists, then there would be an error. 
 
 22 L When a judgment is conformable with the re- 
 ality, or the thing, it is called true. When this is not 
 the case, i*^ is called false, or erroneous. These desig- 
 nations are given to propositions according as they 
 express a true, or false, judgment. 
 
 222. Certitude is a firm assent to a thing. It is of 
 
JUDGMENT AND PROPOSITION. 71 
 
 four kinds : metaphysical, physical, moral, and of 
 common sense. 
 
 223. Metaphysical certitude is that which is founded 
 Ir the essonce of things : three and two make five ; the 
 diameters of a circle are equal : these are instances of 
 metaphysical certitude. 
 
 224. Physical certitude is that which rests on the 
 stability of the laws of nature. 
 
 That the sun will rise to-morrow, is certain with 
 physical certitude. But it is possible for the sun not 
 to rise to-morrow, because Clod can change the laws of 
 nature, by stopping the stars in their career. 
 
 225. Moral certitude is that which rests on the regu- 
 lar order of things. It is morally certain that the 
 magistrate whom we see discharging his duties on the 
 bench, is the acknowledged lawful dignitary; but, 
 without changing either the essence of things or the 
 laws of nature, it would be possible for the supposed 
 magistrate to be an impostor who deceived the public, 
 through an adroit personation of the proper man, and 
 by false documents. 
 
 226. The certitude of common sense is that which is 
 founded neither in the essence of things, nor in the laws 
 of nature, but which makes our assent as secure as physi- 
 cal certitude itself. Such, for example, is the certitude 
 with which we hold that a book can never be made 
 by throwing a font of types at random on a table. 
 
 227. Judgments in which the assent is firm are calledl 
 certain; and they are certain metaphysically, physi- 
 cally, morally, and by common sense, according to the 
 certitude whioh surrounds them. 
 
72 LOGIC. 
 
 228. When there are weighty reasons in favor of a 
 judgment, but yet not sufficient to produce complete 
 certitude, it is called a probable judgment, and, more 
 frequently, it takes the name of opinion. It is clear 
 that opinion can be founded in reasons more or less 
 grave, according to which its probability will have 
 more or less certitude. But, in opinion, it is always 
 necessary not to give a too fij-m assent ; doing this, 
 opinion ceases to be opinion, and is elevated to the rank 
 of certitude. 
 
 229. Doubt is the suspension of the understanding 
 between two judgments. If the suspension arises from 
 a deficiency of reasons, pro or con^ the doubt is called 
 negative. When the suspension comes from an equality 
 of reasons, the doubt is called positive. On the question 
 whether it rains more in New York than in Philadelphia, 
 there being no means to settle it, the doubt is negative. 
 When two witnesses, equal in intelligence, veracity, and 
 every thing else that can give weight to words, take 
 opposite grounds, one affirming what the other denies, — 
 in a case like this, the doubt engendered is positive. 
 
 230. The rules for judging properly are in part ex- 
 plained in what we have said (96, 97), in regard to good 
 perception : for it is evident that when we perceive 
 things well, we attribute to subjects their proper predi- 
 cates. Still, there are some more observations which 
 asist much in avoiding error and in discovering truth, 
 
 ad these will be expounded in the proper place. 
 
BEASONINO. 7S 
 
 CHAPTER V. 
 
 REASONING. 
 
 Section I. — Beasoning in General, 
 
 231. Reasoning is the act of the understanding by 
 which we infer one thing from another. 
 
 232. For this illation we need a means, which is 
 called an argument. The form in which we express a 
 reasoning is called an argumentation. A series of 
 argumentations is denominated an essay, or a discourse. 
 The propositions in which the comparison of the ex- 
 tremes is made with the means, are called premises ; 
 and that in which the consequence is expressed, is 
 called the conclusion. 
 
 233. Strictly speaking, a distinction ought to be 
 drawn between the consequence and the proposition in 
 which it is expressed : this gives us. first, the connection 
 of the proposition with the premises j and, secondly, the 
 proposition purely in itself. Some metal is precious 
 therefore, gold is precious. This last proposition, con- 
 sidered in itself purely, is true ; but, as a consequence, 
 it is false : for, from some metal being precious, it does 
 not follow that gold is precious any more than lead, or 
 iron, or any other metal in the catalogue. Hence it is 
 that consequences are called neither true, nor false, but 
 
 4 
 
74 LOGIC. 
 
 legitimate, or illegitimate. A true proposition can be an 
 illegitimate consequence, as the example given shows ; 
 and a false proposition can be a legitimate consequence. 
 Every mineral is vegetable : therefore, gold is vegetable. 
 The proposition is false, but the consequence is perfectlj 
 legitimate. 
 
 234. The fundamental principle of all reasoning is 
 the principle of contradiction : namely, that it is impos- 
 sible for a thing to be and not to be at one and the same 
 time. The conclusion ought to be already contained in 
 the premises, and, therefore, implicitly affirmed in one of 
 them. Reasoning is the act by which we discover that 
 one judgment is contained in another, and in this dis- 
 covery we use what is called the means. The judge 
 knows that it is his duty to inflict a certain punishment 
 on all thieves : but, as he does not know that a given 
 subject is a thief, he does not know that he ought to in- 
 flict the punishment on him. The judgment, this sub- 
 ject deserves a certain punishment, is contained in the 
 other general one : all thieves deserve a certain punish- 
 ment J but to have this judgment discovered, a deter- 
 mining judgment is necessary, namely, a judgment that 
 the subject is a thief. 
 
 235. This doctrine wiU be better understood by ap- 
 plying it to the various forms of argumentations, which 
 are : the syUogism, the enthymeme, the epicherema, the 
 dilemma, the sorites, or gradation, induction, and 
 analogy. 
 
 Section II. — Definition and Division o) the SyUogism, 
 
 236. The syllogism is an argumentation in which two 
 extremes are compared with a third to discover the re- 
 lation which they have between them. 
 
REASONINO. 
 
 Every virtue is laudable ; 
 Prudence is a virtue : 
 Therefore, prudence is laudable. 
 
 Here the two extremes, prudence and laudable, are 
 compared with the third, — virtue ; and hence it is de- 
 duced that the attribute, laudable, belongs to prudence. 
 
 237. The compared extremes are called terms : 
 major, the most general ; minor, the other and less 
 general. The point of comparison (the means) is 
 denominated the middle term. In the example given, 
 laudable is the major term j prudence, the minor term ; 
 virtue, the middle term. 
 
 238. The premise in which the major term is found, 
 is called the major ; that in which the minor is found, 
 the minor. In general the major is the first premise 
 of the syllogism : but change of place does not vary the 
 nature of either premise. 
 
 239. Syllogisms are divided into simple and compound. 
 The simple consist of simple propositions alone (237) ; 
 the compound contain compound propositions. 
 
 Section III. — The Rules of simple Syllogisms, 
 
 240. As the fundamental principle of syllogisms is, 
 that things which are identical to a third are identical 
 among themselves (237), it follows that all the rules of 
 syllogisms can be reduced to a single one : the compar- 
 ison should be made of the same extremes with the same 
 middle term. But, in the schools, various rules are 
 given, which may be regarded as explanations of the 
 fundamental one. 
 
76 LOGIC. 
 
 241. These rules are expressed in tlie following Latin 
 
 verses : — 
 
 1. Terminus esto triplex: medius, majorque, minorqne. 
 
 2. Latius hos quam praemissse conclusio non vult. 
 8. Aut semel aut iterum, medius genersiliter esto. 
 
 4. Nequaquam medium capiat conclusio fas est. 
 
 5. Ambse affirmantes nequeunt generare negantem. 
 
 6. Pejorem semper sequitur conclusio partem. 
 
 7. Utraque si praemissa neget, nihil inde. 
 
 8. Nil sequitur geminis ex particularibus unquam. 
 
 EXPLANATION. 
 
 I. 
 
 242. Every syllogism ought to consist of three 
 terms and no more : major, minor, and middle ; other- 
 wise, there can be no comparison of the two with the 
 third. 
 
 To make a syllogism vicious, it is not necessary for 
 it to have expressly more than three terms f it is enough 
 for this pupose if one of the terms is taken in a different 
 sense in the different propositions : for then, although 
 the name, or term, is the same, the signification is not. 
 A soldier is valiant ; a coward is a soldier j therefore, a 
 a coward is valiant. The middle term, soldier, is one 
 and the same, in so far as it is a word, but not in signi- 
 fication ; because the soldier spoken of in the major is 
 not the same as the one given in the minor. All the 
 rules can be reduced to this one (235). 
 
 n. 
 
 243. The terms should not be taken in greater ex 
 tension in the conclusion than in the premises. 
 
 This rule is reducible to the first, because, increasing 
 the extension, the terms are changed. 
 
REASONmO. 77 
 
 III. 
 
 244. The middle term, when it is not singular, should 
 be taken distributively in one of the premises. 
 
 If the middle term is not taken distributivelj in one 
 of the premises, but is taken in particular, the applica- 
 tion is made to different subjects in the different premises, 
 as is evident in the example (242). But if the middle 
 term is singular, the syllogism will be conclusive. 
 Csesar was assassinated by Brutus ; the conqueror of 
 Pharsalia was Caesar j therefore, the conqueror of 
 Pharsalia was assassinated by Brutus, 
 
 IV. 
 
 245. The middle term should not enter into the 
 conclusion. The middle term serves for comparing the 
 extremes ; and in the conclusion there should be noth- 
 ing but the result, that is, the relation of the extremes 
 between themselves. 
 
 246. From two affirmative propositions, one negative 
 one cannot be inferred. 
 
 From the identity of two terms with a third, it does 
 not foUow that they should be distinct. 
 
 VI. 
 
 247. The conclusion should follow the weaker part : 
 that is, if one of the premises is particular, or negative, 
 the conclusion should be particular, or negative. 
 
 When a premise is particular, the conclusion should 
 be also particular. 
 
 This appears from previous remarks (243). 
 
 From having one extreme identical with a third, and 
 the other extreme not so identical, it can never follow 
 that one extreme is the other; and, therefore, th^ 
 
78 LOGIC. 
 
 conclusion cannot be affirmative, if one premise ii 
 negative. 
 
 vn. 
 
 248. From two negative propositions nothing fol- 
 lows. 
 
 In the first place, from two negatives an affirmative 
 cannot be inferred. Two terms may be not identical 
 with a third, and yet be not identical among them- 
 selves : therefore an affirmative cannot be inferred 
 from two negative propositions. Caesar is not Pompey, 
 Cicero is not Pompey ; but from this it does not follow 
 that Caesar is Cicero. 
 
 The non-identification of two terms with a third 
 does not prove that they are not identical with each 
 other: and, hence, from two negatives one negative 
 cannot be drawn. Alexander is not Caesar f the con- 
 queror of Darius is not Caesar : but from this it does 
 not follow that Alexander is not the conqueror of Darius. 
 Homer is not Virgil ; the author of the Iliad is not 
 Virgil : but from this it does not follow that Homer is 
 not the author of the Iliad. 
 
 vm. 
 
 249. From two particulars nothing follows. 
 
 If the two are affirmative, all the terms are taken in 
 particular : and consequently, the middle term is 
 neither universal, nor singular (244). If one is nega- 
 tive the conclusion ought to be negative (247) ; in 
 which case the predicate is universal (161). When 
 there is in the premises but one term which is taken uni- 
 versally, it must be either the extreme, or the middle : 
 if it is the middle, the syllogism violates Rule II (243) ; 
 if it is the extreme, it breaks Rule IH (244). 
 
REASONINO. 79 
 
 Section IV. — Figures and Modes of the Syllogism, 
 
 250. According to the place which the middle terra 
 occupies, syllogisms are divided into four classes, called 
 figures. 
 
 In the first, the middle term is subject in the major, 
 and predicate in the minor. In the second, it is predi- 
 cate in both. In the third, it is subject in both. In 
 the fourth, it is predicate in the major and subject in 
 the minor. 
 
 To fix these figures in the memory, the schools use 
 the following formula : prima, sub pr^ ; secunda, prjb 
 PR^ J tertia, sub sub ; quarta, frm sub. 
 
 251. The combination of the propositions of a syllo- 
 gism, according to their universal or particular, or 
 affirmative or negative character, is called the mode of 
 the syllogism. 
 
 The modes are divided into direct and indirect: in 
 the direct, the major term is the predicate of the con- 
 clusion 5 in the indirect, it is the subject. 
 
 252. Representing the quantity and the quality of 
 propositions by the vowels A, -E7, /, (167), and 
 combining them by threes, there are formed 64 combi- 
 nations. But only 19 of these are legitimate, which 
 in the schools are generally expressed in the following 
 well known mnemonic verses : — 
 
 Barbara, Celarent, Darii, Ferio, Baralipton, i 
 
 Celantes, Dabiiis, Fapesmo, Frisesomorum, ! 
 
 Cesare, Camestres, Festino, Baroco, Daripti, 
 Felapton, Disamis, Datisi, Bocardo, Ferison. 
 
 253. In these tnnemonic lines the vowel letters ex- 
 press the propositions. This will be better understood 
 with examples :— 
 
80 LOGIC. 
 
 254. Barbara. As in this word the vowel A it 
 repeated three times, it (the word Barbara) indicates 
 a syllogism composed of three universal aflfirmative 
 propositions. Ferio indicates a syllogism in which the 
 major is a universal negative, JS ; the minor a par* 
 ticular affirmative, // and the conclusion a particular 
 negative, 0. When the mnemonic word has more than 
 three vowels, it is only the three first that are con- 
 wdered : for the others are added only for the cadence 
 of the verse, as in Friseso-morwm. 
 
 255. Barbara. 
 
 A. All metal is body : 
 
 A. All lead is metal: 
 
 A. Therefore, all lead is body. 
 Cclarent. 
 
 E. No metal is vegetable j 
 
 A. All lead is metal: 
 
 E. Therefore, no lead is vegetable, 
 Darii. 
 
 A. All metal is body ; 
 
 I. Some mineral is metal : 
 
 I. Therefore, some mineral is body, 
 Ferio. 
 
 E. No metal is a living thing ; 
 
 1 . Some body is metal : 
 
 0. Therefore, some body is not a living thing. 
 The four preceding kinds belong to the first figure, 
 
 because the middle term, metal, is subject in the major, 
 and predicate in the minor. They are also of the 
 direct mode. 
 
 256. BaraR 
 
 A. All metal is body ; 
 A. All lead is metal : 
 
 1. 1 herefore, some body is lead. 
 
REAsoNma. 61 
 
 CelanteB, 
 
 E. No metal is a living thing j 
 
 A. All lead is metal: 
 
 E. Therefore, no living thing is lead. 
 
 Ddbitis, 
 
 A. All metal is body ; 
 
 I. Some mineral is metal : 
 
 I. Therefore, some body is mineral. 
 
 Fapesmo. 
 
 A, All metal is body ; 
 
 E. No living thing is metal : 
 
 0. Therefore, some body is not a living thing. 
 
 Friseso. 
 
 1. Some mineral is metal ; 
 
 E. No living thing is mineral : 
 
 0. Therefore, some metal is not a living thing. 
 
 These five modes belong to the first figure for the 
 reason assigned (250) ; and they are indirect, because 
 the major term is not the predicate, but the subject of 
 the concha -ion. 
 
 257. Cesare. 
 
 E. No living thing is metal; 
 
 A. All lead is metal : 
 
 E. Therefore, no lead is a living thing. 
 
 Camestre*. 
 
 A. All lead is metal ; 
 
 E. No vegetable is metal: 
 
 E. Therefore, no lead is vegetable. 
 
 Featino, 
 
 E. No vegetable is metal ; 
 
 1. Some body is metal : 
 
 O. Therefore, some body is not vegetable. 
 
d2 LOQia 
 
 Baroco. 
 
 A. All lead is metal ; 
 
 O. Some body is not me^a) . 
 
 0. Therefore, some body i^ not lend. 
 
 These four modes are of the second figur*», because 
 the middle term is always predicate. 
 
 258. Darapti. 
 
 A. All metal is mineral ; 
 A. All metal is body : 
 
 1. Therefore, some body is mineral 
 
 Fciapton. 
 
 E. No metal is vegetable ; 
 A. All metal is body : 
 
 0. Therefore, some body is not vegeUkbUw 
 
 Dtsamis. 
 
 1. Some metal is lead j 
 A. All metal is body : 
 
 I. Therefore, some body is lead. 
 
 Dattsi. 
 
 A. All metal is body ; 
 
 I. Some metal is lead : 
 
 I. Therefore, some body is lead. 
 
 Bocardo. 
 
 O. Some metal is not lead ; 
 A. All metal is mineral : 
 
 0. Therefore, some mineral is not lead. 
 
 Fmson. 
 
 E. No metal is vegetable ; 
 
 1. Some metal is lead : 
 
 O. Therefore, some lead is riot vegetable 
 
 rheae are of tLe third figure. 
 
BEASONIKO. 8$ 
 
 Section V. — Compound Syllogisms, 
 
 259. Compound syllogisms are conditional, disjunc- 
 tive, copulative. 
 
 260. The conditional, or hypothetical syllogism is 
 that which is formed of a conditional proposition, of a 
 simple one in which either of the parts of the condi- 
 tional is affirmed or denied, and of the conclusion. 
 
 The conclusion is called the consequence j the con- 
 ditional, the antecedent : — 
 
 If the sun heats the tube of the thermometer, the 
 
 mercury will rise ; 
 The sun heats the tube : 
 Therefore, the mercury rises. 
 
 EULES ON THE CONDITIONAL SYLLOGISM. 
 
 I. 
 
 261. The antecedent affirmed, the consequence must 
 be affirmed. 
 
 It is cl'^ar that, the relation of the heat of the sun 
 with the i.sing of the thermometer being supposed, the 
 thermometer will rise if this heat is present. But it is 
 to be noted that the affirmation of the consequence 
 does not authorize the affirmation of the antecedent; 
 for we cannot say : if the mercury rises, the sun heats 
 it : because mercury rises under all kinds of heat, as 
 well as under that of the sun. 
 
 II. 
 
 262. The consequence denied, the antecedent must 
 be denied. 
 
 If the mercury does not rise, it is plain that there is 
 no cause to make it rise, and consequently there is no 
 heat acting from the sun. 
 
64 LOGIC. 
 
 But the negation of the consequence cannot be in 
 ferred from the negation of the antecedent. This 
 reasoning would not avail : if the sun does not heat the 
 tube, the mercury does not rise j for the mercury can 
 rise by any kind of heat as well as by solar heat. 
 
 263. The disjunctive syllogism is that which consists 
 of a disjunctive proposition, of a simple one which 
 affirms, or denies, one of the members of the disjunction, 
 and of the conclusion. 
 
 Anthony is French, or German ; 
 
 He is French : 
 
 Therefore, he is not German. 
 
 EXILES ON THE DISJUNCTIVE SYLLOGISM. 
 
 I. 
 
 264. There can be no middle term between the terms 
 of the disjunction. 
 
 The example cited would not be conclusive if Anthony 
 were Spanish, or of some other nation. 
 
 II. 
 
 265. If the conclusion is affirmative, it needs for its 
 legitimacy the negation of all the other members ; and, 
 if it is negative, it needs the affirmation of one. 
 
 The action is useful, or dangerous, or indifferent j 
 
 It is neither useful, nor indifferent : 
 
 Therefore, it is dangerous. 
 Here one extreme is properly affirmed, because all 
 tne others are denied. 
 
 The action is useful, or dangerous, or indifferent : 
 
 It is useful : 
 
 Therefore, it is neither dangerous, nor indifferent. 
 Here one extreme is affirmed, and thervfore the 
 others must be denied. 
 
REASONING. 85 
 
 266. Tho copulative syllogism is that which consists 
 of one copulative negative proposition, of a simple one, 
 and of the conclusion : — 
 
 Man cannot follow the bent of his passions and be 
 virtuous. 
 
 Tiberius follows the bent of his passions : therefore 
 he is not virtuous. 
 
 RULES ON THE COPULATIVE SYLLOGISM. 
 I. 
 
 267. The members of the copulative syllogism should 
 be incompatible. No incompatibility, the syllogism 
 leads to nothing. If one should wish to prove that a 
 wise man is not virtuous by the fact that he is wise, he 
 would prove nothing, for there is no incompatibility 
 between wisdom and virtue. 
 
 n. 
 
 268. The affirmation of one member leads to the 
 negation of the other : — 
 
 If he is virtuous, he does not follow the impulse of his 
 passions ; and if he obeys the impulse of his passions, 
 he is not virtuous. 
 
 in. 
 
 269. The negation of one member does not lead to 
 ihe affirmation of the other : — 
 
 A man cannot be French and Russian : 
 
 He is not French : 
 
 Therefore, he is Russian. 
 The syllogism is not conclusive ; because, although 
 the qualities of French and Russian are incompatible, 
 the man may be neither French, nor Russian, but 
 German, Italian, or a native of some other country. 
 
86 LOGIC. 
 
 Section VI, — The various Jcinds of Argumentation, 
 
 270. The enthymeme is a syllogism in which one of 
 the premises is silent, because, without being expressed. 
 it is understood : — 
 
 All metal is mineral ; 
 Lead is metal : 
 Therefore, lead is mineral. 
 
 This syllogism can be converted into either of these 
 enthymemes : 
 
 1. All metal is mineral: 
 Therefore, lead is mineral. 
 
 2. Lead is metal : 
 Therefore, it is mineral. 
 
 27 L The epicherema, or the proof j is a syllogism 
 whose premises are accompanied with proof: — 
 
 Man ought to profess the true religion, because with- 
 out this it is impossible to please God, who is truth it- 
 self J the Catholic religion is the true one, as miracles, 
 the fulfilment of the prophecies, and other certain 
 evidences attest: man therefore ought to profess the 
 Catholic religion. 
 
 272. The dilemma is an argumentation which consists 
 of a disjunctive proposition, and of two conditionals, 
 both leading to the same conclusion : — 
 
 The world was converted to Christianity either by 
 cnirarles, or without them. If by them, Christianitj 
 has miracles in its favor, and, therefore, it is true ; ii 
 without them, Christianity is in itself a great miracle 
 for converting the world without miracles: therefore, 
 again, it is true. 
 
 The man who obeys his passions either obtains whai 
 he deairesy or not: 
 
REASONING. 
 
 If he obtains what he desires, he becomes disgusted, 
 and, by consequence, unhappy. 
 
 If he does not obtain what he desires, he is anxiou8| 
 ABd, by consequence, unhappy. 
 
 RULES ON THE DILEMMA. 
 I. 
 
 273. There can be no niidddle term between the 
 terms of the disjunction ia the dilemma : — 
 
 The judge either condemns the man to death, or he 
 liberates him ; 
 
 If he condemns him to death, he is cruel, and, there- 
 fore, violates justice j 
 
 If he liberates him, he does not comply with the law, 
 Rnd thus again he violates justice : 
 
 Therefore, whatever he does, he violates justice. 
 
 The dilemma is inconclusive : because between the 
 penalty of death and liberation, there are other punish- 
 ments. 
 
 II. 
 
 274. The conditionals in the dilemma should be true. 
 
 In the example adduced, the syllogism would be in- 
 conclusive if the sentence of death were not cruelty, or 
 if the liberation were not contrary to the law. 
 
 III. 
 
 275. In the dilemma care must be taken against re- 
 tortion : — 
 
 The sovereign either suffers the prisoner to die, or 
 he pardons him. If he suffers him to die, he deserves 
 censure for inhumanity ; if he pardons him, he is also 
 worthy of censure, for he interferes with the operation 
 of justice : therefore, in any view of the case he (lesei*ye0 
 oensure. 
 
88 LOGIC. 
 
 Retorted thus : — 
 
 The sovereign either suffers the prisoner to die, or he 
 pardons him : if he suffers him to die, he does not merit 
 censure, because he allows justice to take its course ; 
 and if he pardons him, he is not deserving of censure, 
 because he is merciful in the exercise of his right : 
 therefore, in no case is he worthy of censure. 
 
 276. The sorites, or gradation, is a series of abbre- 
 viated syllogisms : — 
 
 Mercy is a virtue ; virtue is agreeable to God j that 
 which is agreeable to God gets a reward ; mercy, there- 
 fore obtains a reward. 
 
 This is equivalent to the following syllogisms : Mercy 
 is a virtue ; virtue obtains a reward : therefore, mercy 
 obtains a reward. 
 
 Proof of the minor : that which is agreeable to God 
 obtains a reward : virtue is agreeable to God : there- 
 fore, virtue obtains reward. 
 
 277. Induction is an argumentation by which, enu- 
 merating all the parts, and seeing that to each of them 
 one predicate corresponds, we infer that the same predi- 
 cate is applicable to them all as a class. 
 
 The only rule for this argumentation is to properly 
 enumerate the parts, and not to pass lightly from one, 
 or a few, to all. In general, it is difficult to enumerate 
 all the parts, and hence propositions of too absolute a 
 nature should be guarded against. We will treat of 
 this in another place. 
 
 278. Analogy is argumentation by similitude : as 
 firhen, having found out the cause of a phenomenon, vve 
 infer that other phenomena like it have been produced 
 by the same cause. Of this more extensively in another 
 niaoe. 
 
REASONING. 89 
 
 Section VII. — Paralogisms or Fallacies. 
 
 279. The vicious argumentation is called a paralogism, 
 a sophism, a fallacy. The name of sophism, and less 
 still that of fallacy, is not generally applied to the vicious 
 argumentation, when the latter is used in good faith. 
 In that case, it is called a paralogism. But some give 
 the name of paralogism to the argumentation which is 
 vicious in its matter ; and of sophism, or fallacy, to that 
 which is wrong in its form. 
 
 280 Although the vicious argumentations can be 
 detected by the rules which we have given in pre- 
 ceding pages, we will rapidly enumerate those gener- 
 ally counted in the schools, according to Aristotle. 
 
 281. The fallacies are thirteen: six of diction, and 
 seven of the thing. The first are called grammatical j 
 the second dialectical. 
 
 282. Those of diction, or of word, are the following : 
 equivocation, amphibology, composition, division, ac- 
 cent, figure of speech. Some of these are strange and 
 even ridiculous: — 
 
 Equivocation. — The climate is delicious : therefore, n 
 is grateful to the palate. 
 
 Amphibology. — He who sinks his wealth in enter- 
 prises does a mad act ; therefore, it is necessary to put 
 him in bedlam. 
 
 Composition — or transition from the sense divided to 
 the sense collected : — He who is sitting down can stand 
 on his feet : therefore, at one and the same time h* 
 can sit and stand. 
 
90 LOGIC. 
 
 Division — or transition from the sense collective to 
 the sense divided : — White cannot receive a flesh tint ; 
 therefore, paper cannot receive a flesh tint. 
 
 Accent — If he is just. If he is just. The first is 
 absolute j the second conditional. 
 
 Figure of Speech. — The existence of Mars is fabulous : 
 therefore, there is no planet Mars. 
 
 283. The following are the fallacies of the thing : — 
 Accident j transition from the dicto simpliciter to the 
 dicto secundum quid, or from the dicto secundum quid 
 to the dicto simpliciter ; ignoratio elenchi j consequence ; 
 petitio principii ; non-cause for cause j taking the 
 complex for the simple. 
 
 284. Accident (fallacia accidentis). — Some wise men 
 have been vicious ; therefore, science is dangerous. 
 Here science is condemned by reason of an accident. 
 
 285. Transition from the dicto simpliciter to the dicto 
 secundum quid, and reciprocally. — The man deceives : 
 therefore, he lies. This is not conclusive, because the 
 man may act in good faith. We do not know the cause 
 of the terrestrial heat : therefore, we do not know that 
 the cause exists. Non-conclusive, also. 
 
 286. Ignoratio elenchi. — Bringing into the question 
 <vhat does not belong to it. Man cannot think without 
 blood : therefore, blood thinks. To investigate the sub- 
 ject of thought, is not the same as investigating a con- 
 dition necessary for life, and, consequently, for thought. 
 
 287. Consequence. — The fallacy of consequence is 
 oommitted when the rule given in No. 260 is violated ^ 
 
REASONINQ. 91 
 
 as : if he is wise, he is laborious j he is wise : there- 
 fore, he is laborious. 
 
 288. Fetitio principii, — Begging the question. This 
 fallacy is made when the thing to be proved is supposed 
 as proved. As : smoke ascends in the aii: because it 
 has no gravitjjj, for it belongs to the class of light bodies 
 Precisely, this last is the thing to be proved, but it is 
 taken as proved. The petitio is also called the vicious 
 circle, 
 
 289. Non-cause for cause, — The patient is worse : 
 therefore, the physic has done him harm. The harm 
 could have arisen from other causes. 
 
 290. I%e complex for the simple, — Are the Mexicans, 
 the Brazilians, the Spaniards, the French, Europeans t 
 Yes. Are the Mexicans Europeans? No. There- 
 fore, the French are not Europeans. 
 
 Section Vni. — Beduction of all the Bules of Reason- 
 ing to one, 
 
 291. We have said (235) that all reasoning consists 
 m showing that one judgment is contained in another. 
 W^e now proceed to explain this observation, which, if 
 well understood, is sufficient for knowing whether any 
 •easoning whatever is legitimate or not, without the 
 necessity of recollecting the special rules. 
 
 292. The legitimate consequence should be affirmed 
 In the premises. Tx) draw it out is to make explicit 
 what is implicit ; the means is only the instrument for 
 unfolding the premises, and showing that inoneoftliem 
 the conclusion is contained. From this it follows that 
 all reasoning is founded on the principle of contradiction; 
 
92 LOGIC. 
 
 and every consequence, in order to be legitimate, should 
 be such that, not admitting it, gives the contradiction of 
 a thing being and not being at one and the same time 
 
 293. A sophism is an argumentation in which an illegi- 
 timate consequence is deduced with the appearances of 
 legitimacy. In every sophism it is pretended that one 
 judgment is contained in another, when really it is not. 
 The secret for disentangling sophisms is to unsay them 
 in what they assert, reflecting attentively on the true 
 sense of the proposition on which the fallacy rests. 
 
 294. By the aid of these observations it can be set- 
 tled at once whether an argumentation is legitimate, 
 or sophistical. In dialectics many rules are given for 
 this purpose ; their utility is not denied, and in these 
 pages they have not been at all depreciated ; still it is 
 difficult to retain them in the memory *, and, although 
 they may be remembered, it is yet the case that each of 
 them rests on the principle laid down, namely, the 
 principle of contradiction. 
 
 Let us apply this remark to a simple syllogism. 
 
 295. The fundamental principle of simple syllogisms 
 is the following : things identical to a third thing are 
 identical among themselves. This principle is reducible 
 to the principle of contradiction. If ^ is (7, and IB is (7, 
 A is B. It being given that A is (7, it is evident that, 
 when I say that ^ is (7, I also say that A is B, If 1 
 deny it, I fall into the contradiction of affirming and 
 denying one and the same thing at one and the same time. 
 
 296. Hence it is that all the rules of the syllogism 
 can be reduced to a single one : namely, to compare 
 the same extremes with the same means. On the other 
 hand, all the vices of syllogisms are reduced to one : 
 
REASONING. 99 
 
 the change of the extremes or of the means, even 
 though the words which are used remain unaltered. 
 
 297. All body is heavy: the air is a body: there- 
 fore, the air is heavy. The consequence is legitimate ; 
 because, having affirmed that every body is heavy, I 
 affirm the same thing of air, if air is a body : the con- 
 clusion, therefore, is contained in the major; and all 
 needed for the manifestation of the minor is to say that 
 the air is a body, that is, one of those things of which 
 weight is affirmed. 
 
 298. This species of syllogism rests on the principle: 
 that that which is affirmed of all, is affirmed of each 
 one. The use of the principle of contradiction is evi- 
 dent in this case : for, when I speak of all distributively , 
 I also speak of each one. If I affirm a predicate of all 
 bodies, and then deny it of one body, I affirm of all and 
 not of all, which is a contradiction. 
 
 29^. Some body is vegetable ; metal is body : there- 
 fore, .-uetal is vegetable. The syllogism is non-conclu- 
 sive ; because, in affirming that some body is vegetable, 
 the affirmation belongs only to certain bodies j and in 
 affirming in the minor that metal is a body, I refer to 
 bodies different from those intimated in the major : 
 there is, therefore, no comparison of the two extremes 
 with one and the same means ; and, consequently, there 
 is no contradiction in denying that they are identical 
 among themselves. Tli^ defect of this syllogism ia 
 expressed in the rule, — that from two particular pro- 
 positions nothing follows. 
 
 300. All pine is timber ; all silver tree is timber : 
 therefore, all silver tree is pine. Non-conclusive : because 
 ifi the major the middle term expresses one kind of 
 
94 LOGIC. 
 
 timber, and in the minor a different one. The fault of 
 this syllogism is indicated in the rule, — that in one of 
 the premises the nddcHe term should be taken distribu 
 tively. The reason is : this gives a comparison with one 
 and the same means : for when, in one of the premises, 
 expression is made of allj it follows that the other 
 premise m speaking of one, contained in the same all, 
 expresses what the first premise has already declared. 
 
 301. It is easy to extend these observations to all the 
 forms of argumentation ; and an exercise of this nature 
 would be good for students, because it would accustom 
 them to distinguish between legitimate and sophistical 
 reasoning j and, simplifying the rules of all good argu- 
 mentation, they would retain them without difficv \tj in 
 the memory. 
 
THE CRITERIA. 
 
 BOOK THIRD. 
 
 METHOD. 
 
 CHAPTER I. 
 
 THE CRITERIA. 
 
 802. Method is the order which we observe for 
 ■voiding error and finding truth. 
 
 Sometimes, by method is understood a body of meani 
 for achieving an end. We shall treat of the two things 
 in this book. 
 
 303. The sources whence .e get the knowledge of 
 truth, are called criteria ; and it is clear, that, if we 
 did not know these criteria, it would be impossible to 
 proceed in good order in the investigation of truth. 
 Hence, before giving the rules of method, it is neces- 
 sary to explain in what the criteria consist. 
 
 In general, by criterion is understood a means for 
 
 owing truth. 
 
 There are two classes of criteria : those which are in 
 ourselves, and they are the criterion of consciousness, 
 of evidence, of common sense, and that of the external 
 lenses ; the second kind is that which is outside of 
 ourselves — as authority. We will explain farther on 
 (Section HI), that the criterion of the external senses 
 ts reduced to the criteria of consciousnesa and common 
 
J6 IX)GIC. 
 
 ■cnst, ^r rather, that it is formed of the combination oi 
 these two. It will also be shown that the criterion of 
 authority is composed of that of the consciousness, of 
 common sense, of evidence, and of the external senses. 
 
 Section l^^Ihe Criterion of Consciousness^ or of the 
 Internal Sense, 
 
 304. The consciousness, or the internal sense, is the 
 internal presence of our state of mind. To feel, to 
 imagine, to think, to wish, are affections of our soul, 
 which cannot be conceived without their internal pre- 
 sence. What would feeling be, if we did not experience 
 the sensation ? What would thinking be, if we did not 
 experience the thought ? What would wishing be, if wc 
 did not experience the act of the will ? The feeling, 
 the imagination, thought, will, would all disappear, if 
 there were not this inward presence j for then every 
 thing would be reduced to words that either signified 
 nothing, or that expressed contradictory things. 
 
 305. The consciousness acts in two ways ; the direct, 
 and the reflective. The direct consists in the simple 
 presence of the intei nal affection ; the reflective is the 
 intellectual act which is directed on this presence. I 
 feel a pain, without expressly thinking that I feel it : 
 the internal presence of the painful affection is direct 
 consciousness. But if I think on the sensation so as to 
 exercise an intellectual act which may be thus ex- 
 pressed, "I know that I suffer," — then there is reflective 
 consciousness. 
 
 306. The direct consciousness accompanies all in- 
 ternal affections : without it, neither sensibility, nor 
 intelligence, nor will, is conceivable. 
 
 307. Some believe that there are intenaal intellertuaJ 
 
THE CRITERIA. 97 
 
 affections of which we have no consciousness : if 
 reflective consciousness be meant, it is certain that there 
 are manj affections of which we do not expressly take 
 note ; but, on direct consciousness, the assertion weuld 
 be contradictory. 
 
 308. The criterion of the consciousness is all infallible, 
 provided it is confined to its own sphere. This sphere 
 is that which passes in our interior. If I experience a 
 nain like that which a blow produces, I cannot be 
 deceived in the consciousness telling me that I feel that 
 pain. If the consciousness tells me I feel it ; to feel 
 it, to experience it, to have consciousness of it, to find 
 it present in my soul, — these are identical things : to 
 affirm one of them and deny the others, would be a 
 contradiction. 
 
 309. The errors of the criterion of the consciousness 
 arise from passing from internal affection to its causes, 
 or to circumstances which are not under its jurisdiction. 
 I am not, and I cannot be deceived, if, in experiencing a 
 pain like that of a blow, I affirm that I experience it : 
 but if, besides saying that I experience the pain I tell 
 the causes of the blow, still using the same criterion, 
 then I can be deceived : because in that case the criterion 
 operates out of its sphere. 
 
 310. A man experiences an impulse to a certain 
 belief, or towards a certain action : interiorly, it appears 
 to hira that he hears a voice inculcating such a doctrine 
 to be accepted, or advising such a course to be pursued: 
 he is not, and he cannot be deceived as to the internal 
 phenomenon, provided he limits himself to saying; 
 *^ within I feel this ;" thus far the criterion of his con- 
 sciousness is infallible. But if, resting on this criterion, 
 he says, God has inspired me to do this : then h« 
 
 5 
 
98 LOGIC. 
 
 passes from the phenomenon to the cause, and he ia 
 liable to error. This is the spring of the fanaticisms 
 and of the extravagances of the sects who have aban- 
 doned the principle of authority, to found themselves 
 on private judgment alone. 
 
 The entire doctrine of the criterion of the conscious- 
 ness is summarized in the following rules : — 
 
 RULES ON CONSCIOUSNESS. 
 I. 
 
 311. The criterion of the consciousness is infallible 
 when it refers to what passes in our interior. 
 
 11. 
 
 312. The criterion of the consciousness is fallible 
 when it goes beyond the limits of what passes in our 
 interior — taking in causes, effects, or other circum- 
 tances of the internal phenomenon. 
 
 Section II. — The Criterion of Evidence. 
 
 313. Evidence is generally defined : the internal light 
 by which we perceive ideas with all clearness. This 
 definition has the inconvenience of being composed of 
 metaphorical words, which need to be explained. It is 
 therefore insufficient, and it is necessary to examine 
 to the foundation this important point. 
 
 314. It is evident that three and two make fivw 
 Wherefore T Because, analyzing that which we under- 
 stand by five, we see that in this idea are found the 
 three and the two, and that the five is nothing but the 
 union of these two numbers. It is evident that tlirec 
 and two are not six. Why ? Because, analyzing wlmt 
 we understand by six, we see that this number is com- 
 poied of three, plus two, plus one; and, therefore, the 
 
THE CRITERU. 99 
 
 dnion of the three and the two does not complete the six. 
 It is evidf nt that all the radii of a circle are equal. 
 Why ? Because, examining what we understand by a 
 circle, we see that in its construction the equality of the 
 radii ik Hupposed. It is evident that the diameter is 
 greatf^^ than the radius. Why ? Because, examining 
 what we understand by diameter, we see that it is 
 formed of two radii — of one put in continuation of 
 another. 
 
 315. Evidence, therefore, may be defined: the per- 
 ception of the identity, or of the repugnance of ideas. 
 
 316. Speaking in rigor, evidence is the act by which 
 we find in our ideas that which is in them, or by which 
 we deny what we deny of them. It is a species of loading 
 and unloading by which the understanding balances the 
 discharges with the arrivals : that which has not been 
 received cannot be discharged; and that which has 
 been discharged, is no longer present. 
 
 Ah evidence is founded on the principle of contra- 
 diction ; the understanding has no evidence but when 
 it d'flcovers a conflict between affirmation and negation j 
 it affirms with evidence, because it cannot deny without 
 contradicting its own affirmation ; it denies with evi- 
 dence, when it cannot affirm without being at variance 
 with its own negation. 
 
 ol7. Evidence is immediate and mediate. Ther^ -h 
 immediate evidence when we instantly perceive the 
 ,'identity, or the repugnance, of two ideas, without tlie 
 necessity of any reflection, and by simply under- 
 standing the meaning of the words in which the thing 
 is declared. 
 
 There is mediate evidence when, to discover the 
 identity^ or the repugnance of ideas, it is necessary to re- 
 
100 LOGIC. 
 
 fleet on them, examining them under various aspects, 
 or comparing them with other ideas. If a circular 
 triangle is spoken of, we see the absurdity at once without 
 any reflection, because the simple idea oi' triangle ex- 
 cludes that of circle : this is evident with immediate 
 evidence, and for all men — for the ignorant as well as 
 for the masters in geometry. But one uneducated in 
 the elements of this science, could very well believe 
 that a triangle, the sum of whose angles is greater than 
 two right angles, is not absurd. This is impossible — 
 contradictory : but, the contradiction is not discovered 
 at first sight, even although it may be known what an 
 angle is, what the triangle, and what the two right 
 angles are. Here, then, there is not immediate evidence. 
 But, by the knowledge of the way to compare angles, 
 it is demonstrated that the sum of the angles of a tri- 
 angle is always equal to two right angles, and that the 
 opposite cannot be held without falling into contradic- 
 tion. In this case there is mediate evidence. 
 
 318. The touchstone of true evidence is the principle 
 of contradiction, and the illusions which we form with 
 this criterion arise from the bad application of the same 
 principle. In instances of immediate evidence there ia 
 no difficulty. But when, to perceive identity, or repug- 
 nance, we are under the necessity of comparing 
 various ideas among themselves in a long process of 
 reasoning, then it is essential to be careful. 
 
 RULES ON EVIDENCE. 
 I. 
 
 319. To be certain that we have, in fact, immediate 
 evidence, it is necessary to see, at the first look and 
 with aU clearness, that the judgment is interlaced with 
 the principle of contradiction : that is, that if the pro- 
 
THE CRITERIA. 101 
 
 position is affirmative, it cannot bv^ denied, or that if it 
 is negative, it cannot be affirmed without violating this 
 principle. 
 
 11. 
 
 320. Wlien there is not immediate evidence, it is 
 necessary to follow the acts of reasoning with the 
 greatest carefulness, and never to go beyond the limits 
 permitted by the principle of contradiction. 
 
 Section III. — The Criterion of Common Sense, 
 
 321. The criterion of common sense, which may be 
 also called intellectual instinct, is the natural inclination 
 we have to give assent to certain propositions which we 
 hold neither by evidence, nor by the testimony of the 
 consciousness. It is easy to show many examples ot 
 this irresistible instinct. 
 
 All men are certain that there is an external world : 
 and yet they have not this certainty from their con^ 
 Bciousness, for consciousness is limited to phenomena 
 purely internal ; nor do they know the fact by evidence, 
 because, even supposing the possibility of a true de- 
 monstration, many would be incapable of comprehend- 
 ing it, and because the majority have never thought, 
 and never will think, of such demonstrations. 
 
 All humanity knows the moral truths, and adjusts its 
 conduct according to them : at least all men know that 
 they ought to do this. These truths are not pui«ly in- 
 ternal phenomena, for they express the relations man 
 has with himself, with his fellow-man, and with God* 
 Nor are they known by demonstrations, for the im- 
 mense majority of men, although moral beings, do not 
 think on moral theories. 
 
 N i> one believes that acts performed at chance always 
 give the desired result ; that firing without aim always 
 •Jls the paiticular bird; that going without seeini 
 
102 LOGIC. 
 
 wrhere, the proper place is always reached ; tliat put- 
 king the hand in an urn containing thousands of litttie 
 balls, a certain one is sure to be drawn , that moving a 
 writing pen at random, gives for result every kind of 
 literary composition that may be wanted. The certitude 
 that these extravagances do not succeed, rests neither 
 on the testimony of the consciousness, for that is con- 
 fined to internal phenomena ; nor on evidence, because, 
 in the occurrence of such extravagances, there is no 
 opposition to the principle of contradiction. 
 
 322. The preceding examples show that there is in 
 lis an intellectual instinct which impels us in an irre- 
 sistible manner to give assent to certain truths which 
 are attested neither by consciousness, nor bv evidence. 
 This instinct is called the criterion of coidmon sense. 
 We call it intellectual instinct. It has the name of 
 sensej because it seems to have something in it resem- 
 bling a sentiment ; and it is called common, becauise, in 
 fact, it is common to all men. Those who put them- 
 selves in contradiction with this universal instinct, those 
 who have not the common sense, may be looked on aa 
 monstrous exceptions in the order of intelligence. 
 
 323. The criterion of the senses consists of two ele- 
 ments : the testimony of the consciousness, and the 
 intellectual instinct. B^ the first, we are certain of the 
 presence of the internal phenomena, of the sensatioir 
 considered in itself, inasmuch as it is a fact purely 
 iubjective ; by the second, we attribute reality to the 
 object of the sensations, making a transition from the in- 
 ternal phenomena to the external world, not thinking at 
 all of how this transition is made. 
 
 324. The criterion of evidence is also founded in th^ 
 testimony of the consciousness combined with the inteJ 
 
THE CRITERIA. 108 
 
 lectual instinct. We believe not only that things ap- 
 pear to us as such, but also that they are such as they 
 appear to us. It appears to us that a circle is not » 
 triangle : but we do not limit ourselves to the affirma- 
 tion of appearance. We affirm that, in reality, and inde- 
 pendent! r of internal appearance altogether, a circle can- 
 not be a triangle. It appears to us that a thing cannot be 
 in and out of existence at one and the same time ; bat 
 our assent is not confined to appearance: it extends to 
 the thing i'tself, and we are certain that in reality, in- 
 dependently of our understanding, this contradiction can 
 never be verified. The testimony of the consciousness 
 is limited to appearance: why then do we pass from 
 appearance to reality ? why do we confer an objective 
 value on our ideas If why do we not regard them as facts 
 purely subjective, to which things could be conformed, 
 or not? The answer is in the intellectual instinct. 
 That is an irresistible impulse for which we cannot give 
 any reason either from consciousness, or from evidence, 
 or from any source, under the penalty of proceeding ad 
 infinitum. Thus it appears to me, thus it is, and it can- 
 not be in any other way. Why ? For such a reason. 
 And in what is this reason founded! In another 
 appearance. And thus we should go on for ever, always 
 stopping at our interior, at a fact purely subjective, 
 without being able to give any other reason for the 
 transition we make from subject to object, but that 
 which nature has formed in us. 
 
 325. The criterion of human authority is formed of a 
 combination of the criteria already explained. We 
 hear an account of an occurrence which we have not 
 witnessed, and we credit the narrator. Here it is ne- 
 cessary, first, to hear the narrator's words, and thia 
 gives the criterion of sense ; second, to know that the 
 narrator is neither deceived himself, nor deceiving ua : 
 
104 LOGIC. 
 
 and this we find out by reasoning. Finally, perhaps, 
 we believe the narrator instinctively, and then we act 
 by the common sense. 
 
 326. What is here said on human authority showa 
 tlial that criterion may lead us into error in various 
 ways ; because, to be deceived by it, it is sufficient to 
 make an imperfect use of the other criteria. We may 
 deceive ourselves by hearing and reading negligently ; 
 and error and bad faith in thone who address us, are 
 competent to produce the same result. 
 
 The common sense, to be infallible, should have the 
 following conditions, or rules : — 
 
 KULE8 ON COMMON SENSE. 
 
 1. 
 
 327. The inclination to the assent must be irresisti- 
 bie, so that it cannot be shaken off, even by reflection. 
 
 n. 
 
 328. Every truth of common sense is absolutely cer- 
 tain for the whole himian race. 
 
 in. 
 
 329. Every truth of common sense can bear the test 
 of reason. 
 
 IV. 
 
 330. Every truth of common sense has for its object 
 the satisfaction of some great necessity of the sensidve) 
 intellectual^ or moral life of man. 
 
THE CRITERIA. 105 
 
 331. When these cliaracters are found together, tlio 
 criterion of the common sense is absolutely infallible ; 
 and sceptics who then present an exception against it 
 may be discredited. In proportion as these conditions 
 are united in the highest degree, all the more certain is 
 the criterion of the common sense. 
 
106 LOGIC. 
 
 CHAPTER II. 
 
 HOW WE SHOULD ACT Oi^ THE VARIOUS QUESTIONS 
 THAT ARE OFFERED TO OUR UKDERSTANDING4 
 
 Sectio]S' 1. — General Classification of Questions, 
 
 332. The acts of the understanding are divided into 
 speculative and practical : the first are confined to 
 knowledge ; the second direct us in our operations. 
 
 333. In the simple knowledge of a thing there are 
 three questions : 1st, Is it possible, or not ; 2d, Does 
 it exist, or not ; 3d, What is its nature — what are its 
 properties and relations? 
 
 334. In practical questions we always design some 
 end, which gives two considerations : 1st, What is, or 
 what ought to be the end ; 2d, What are the best 
 means for achieving the end ? 
 
 Section II. — Questions of Possibility. 
 
 335. Impossibility, as impossibility, is metaphysical, 
 physical, ordinary, and of common sense. Each kind 
 gives rise to important considerations. ^ 
 
 metaphysical, or absolute impossibility. 
 
 336. Metaphysical, or absolute impossibility, is that 
 which implies contra<liction, or, in other terms, that 
 
VARIOUS QUESTIONS. l67 
 
 which lias in it the absurdity of a thing beitig and not 
 being at one and the same time. Two plus two are equal 
 to three ; the diameters of the same circle are unequal ; 
 virtue is reprehensible ; vice is laudable : these things 
 are absolute impossibilities ; the first, for it asserts that 
 three at'e three and not three ; the second, for it declares 
 that the circle is a circle and not a circle ; and the third 
 and fourth, for they lay down that virtue and vice are 
 vice and virtue, at one and the same time. 
 
 The following rules should be observed in judging on 
 metaphysical impossibility : — 
 
 RULES Oia METAPHYSICAL IMPOSSIBILITY. 
 I. 
 
 337. There is absolute impossibility when the idea 
 of one thing evidently excludes that of another. 
 
 This evidence is the light with which we judge of first 
 principles. We know that it is impossible for a thing 
 to be in existence, and out of existence, at one and the 
 same time, that the whole cannot be less than a part, 
 that the radii of the same circle are unequal ; for we 
 see this impossibility in all evidence by the simple 
 comparison of ideas. 
 
 II. 
 
 338. When there is no contradiction, the thing is 
 absolutely possible. 
 
 Absolute, or metaphysical, possibility is no more than 
 the simple absence of contradiction ; and, therefoi-e. 
 between the possible and impossible there is no middle 
 ground : by the mere fact that a thing is not contradic- 
 tory, it is absolutely possible. 
 
 III. 
 
 339. When, at the first sight, we do not discover 
 
108 LOGIC. 
 
 thiit two ideas are in contradiction, it is 'necessary to 
 compare tliem with other ideas which may illustrate 
 them. 
 
 This proposition, — the three angles of a triangle are 
 more than two right angles, — is contradictory ; but the 
 contradiction is not evident to one unacquainted with 
 the elements of geometry. In sucli a case the thing to 
 be done is to compare tlie two ideas, namely, the sum of 
 the three angles of the triangle, and that of two right 
 angles, with the nature of triangle itself. This shows 
 the contradiction. 
 
 IV. 
 
 340. The metaphysically impossible is so under all 
 aspects, and no power is capable of realizing it. 
 
 Three and two can never make seven. Blasphemy 
 can never be a virtuous act. When it is said that God 
 can do all things, it is not understood that He can do 
 what is absurd ; otherwise it would follow that He could 
 sin, and even destroy himself. 
 
 v. 
 
 341. In affirming absolute impossibility, it is neces- 
 sary to have very clear and distinct ideas of the ex- 
 tremes compared. 
 
 All the arguments used in proving that there are 
 contradictions in the mysteries of religion, violate this 
 rule ; for their authors attempt to prove contradictions 
 in things of which they have very obscure ideas. 
 
 VI. 
 
 342. When the contradiction is evident, we have a 
 sure criterion for denying the reality of the contra- 
 diction in all cases. 
 
 Hence is verified without any exception the principle, 
 th;i,t, when the power to do an act is denied, the act 
 itself must be denied ; because the thing that is ubso- 
 
VAEIOUS QUESTIONS. 109 
 
 lutely impossible, can never be. A circle can never be 
 a triangle. Virtue can never be reprehensible. 
 
 PHYSICAL, OR NATURAL IMPOSSIBILITY. 
 
 343. Physical, or natural impossibility is the opposi- 
 tion of a fact to the laws of nature. It is not absolutely 
 impossible for a dense body to mount up in the air : 
 but it is physically so, for such a thing is in opposition 
 with the laws of gravity. 
 
 To judge properly on this subject, it is necessary to 
 observe the following rules : 
 
 RULES ON PHYSICAL IMPOSSIBIITY. 
 
 344. Avoid deciding with too much haste that a fact 
 is contrary or not to the laws of nature. If in the last 
 century it had been said that there was a country in 
 which, without the aid of horses or other animals, the 
 people travelled twenty leagues an hour, there would 
 have been many to say that such a thing was naturally 
 impossible. But this is done to-day in all countries 
 by means of steam. The electric telegraph is another 
 instance. The civilized world is full of the realization 
 of things which were once believed to be naturally 
 impossible. 
 
 II. 
 
 345. To discover that a fact is naturally impossible, 
 it is necessary to consider the causes in operation to 
 produce it, and the circumstances by which it is sur- 
 rounded. 
 
 In remote ages, the phenomenon of the railroad 
 would not have appeared impossible to one who 
 followed a good method in the investigation of its pos- 
 
110 LOGIC 
 
 eibility. Among the machines of those times, howevei 
 rude they were, there were some in the list that were 
 not moved by animal power, and that moved at various 
 degrees of swiftness. With these facts for a foundation, 
 the question of the possibility of a new agent of motion 
 was natural enough. To a man of judgment, the solution 
 of this question might have appeared difficult, but not 
 Iiupossible. The telegraph is another instance. The 
 transmission of signs by electricity wo aid not have ap- 
 peared impossible to a man who knew the velocity of 
 the air in transmitting sounds, and of bodies of light in 
 diflPusing their rays. For such a man the problem was 
 reduced to this : is it possible that in time men will 
 discover some natural agent by whose means they can 
 imitate those instantaneous transmissions ? The reso- 
 lution could not have been doubtful, however narrow 
 the state of the natural sciences may have been. 
 
 346. We assist at an entertainment in wnich a man 
 transforms various objects. There is no apparatus. 
 The means he employs are mysterious words, and ex- 
 travagant movements of the hands. Watching all the 
 circumstances of person, of place, of time, we perceive 
 no causes sufficient to produce such surprising per- 
 formances. What judgment should we form 1 This : 
 that there is present no secret action of the laws of na 
 ture, but that the whole thing depends on the ability of 
 a dexterous juggler, who offers appearances for realities. 
 To decipher the enigma, all our attention should be 
 directed not to the efficacy of the laws of nature, but t(. 
 the hands of the showman, to the instruments he 
 uses, or to cunning assistants near him. On the other 
 hand, if we should see astounding things in the 
 experimenting office of a natural philosopher, where 
 there is no disguise of the various apparatus for moving 
 ^d combining the agents of nature, we should hp««tate 
 
VARIOUS QUESTIONS. IIJ 
 
 to affirm that any thing we witnessed, however won 
 derful it may be, was naturally impossible. 
 
 ORDINARY, OR MORAL IMPOSSIBILITY. 
 
 347. Ordinary, or moral impossibility consists in op 
 position to the regular, or ordinary course of things. 
 
 It is morally impossible that a person, generallj 
 knov/n by a certain name and surname and by hii 
 position in society, is not the man whom all believe 
 him to be. But it is possible for that person to be an 
 impostor who has taken advantage of favorable circum- 
 stances to put himself where he is. There are many 
 instances of this kind of deception. 
 
 In this class of judgments the following rules are to 
 be observed: — 
 
 RULES ON MORAL IMPOSSIBILITY. 
 I. 
 
 348. When there is no contrary sign, we must b( 
 Batisfied with the criterion of ordinary impossibility. 
 
 Society and families rest on this criterion. If wf 
 needed absolute, or natural certainty in all things, j 
 would be necessary to renounce our relations with men 
 
 11. 
 
 349. To decide in a given case on the certainty of 
 moral impossibility, an examination should be made in- 
 to the causes that might make possible the contrary 
 fact. 
 
 It is morally impossible for a firm assent, generally 
 received, to be untrue. This security should satisfy ua 
 in matters of minor importance. But, in things of 
 consequence, the least indication of error should b^ 
 enough to weaken the idea of moral impossibility 
 This is attest^-^ by coinmon experience. 
 
112 LOGIC. 
 
 THE IMPOSSIBILITY OF COMMON SENSE. 
 
 350. The impossibility of common sense does Eot 
 belong to any of the preceding kinds. Examples will 
 explain what it is, better than any definition. A man 
 has in his hand a quantity of pebbles, and he pretends 
 that, closing his eyes, and then pelting them at random, 
 he can make each one of them pass through a hole equal 
 to itself in dimensions. Twenty blindfolded men take an 
 equal number of loaded rifles in their hands ; before 
 firing they are made to move their weapons in various 
 directions ; and then it is pretended that each of them 
 can send his bullet through a hole corresponding to it- 
 self in diameter. Another man proceeds to scatter a 
 case of types on a table, and it is claimed that the result 
 will be a piece of copy regularly set up. It is clear that all 
 these things are impossible : and yet in none of them is 
 there that essential repugnance of ideas, which absolute 
 impossibility demands. Nor is any of them in opposition 
 even with the laws of nature after the manner of physi- 
 cal impossibility. But the impossibility manifested is 
 that of common sense : for, without any reflection, all 
 men believe that undertakings of these kinds can never 
 be realized ; and the belief of mankind against the per- 
 formance of such acts is much stronger than that which 
 arises in instances of ordinary impossibility. Thii 
 shows that these two impossibilities should not b« 
 confounded. 
 
 RULES ON COMMON SENSE IMPOSSIBILITY. 
 
 I. 
 
 851. In aU cases like the preceding, which produce a 
 general and instantaneous conviction, the impossibility 
 of common sense is a sure criterion that the fact hat 
 Dot been, and never can be, verified. 
 
VARIOL-S QUESTIONS. 113 
 
 n. 
 
 352. When the conviction on this impossibility is not 
 general and instantaneous, the event is more or lesi 
 probable. 
 
 To determine the degrees of this probability, a frac- 
 tion ought to be formed whose numerator represents 
 the favorable cases, and whose denominator stands for 
 the possible ones. 
 
 In an urn containing ninety-nine white balls and one 
 black one, the probability of drawing the black one is 
 equal to t^tt: because there are a hundred possible 
 cases, for the balls are a hundred ; and there is only 
 one favorable case, which is the solitary black ball. So 
 that there are ninety -nine degrees of probability in 
 favor of each white ball, while there is only a single 
 degree for the black one. 
 
 353. Thus we understand the profound reason which 
 is imbedded in the impossibility of common sense. Let 
 us suppose a man placed in the centre of a great hall ; 
 his eyes are bandaged ; a rifle is put in his hand ; and 
 by a random shot he is required to send the ball through 
 a hole an inch in diameter. All would say at once, 
 
 'thout any reflection, that such a feat is impossible. 
 And why I They do not know it ; and yet a calculation 
 will show the depth of this instinctive judgment. The 
 supposed hall has four waUs, each twenty yards long, 
 and eight in height. AU this surface is equal to 829, 
 440 square inches ; and as the hole could be in any one 
 of these squares, it is clear that the number of possible 
 cases is 829,440, while there is but one favorable case. 
 The probability of the required feat can then be thus 
 expressed -gsajjjo. But the probability is even much 
 less than this. To demc nstrate this, let us suppose that 
 all the square inches of the four walls are painted : in 
 
114 LOGIC. 
 
 that event, if cue should be holed, the probability in 
 its favor would not be expressed by the fraction given. 
 That fraction gives the idea that the nuraber of the 
 possible cases is one of the marked, or painted inches, 
 and that if the ball does not go through one of them it 
 will go through another. But this is incorrect, for tlie 
 ball may go through the lines separating the squares. 
 
 And thus we see that the probability of performing 
 the required act is what may be called infinitely littJe 
 
 Section. — III. Coexistence and Succession, 
 
 354. To know the existence of an unknown thing, 
 we are compelled to begin at a known thing, and we 
 must know, in addition, that the two things are united 
 by some bond. Without this it is impossible to proceed. 
 How can I acquire a knowledge which I have not, if 
 I have not something on which to rest ? such an act is like 
 designing an edifice without a foundation. 
 
 355. Of objects, some are subjected to our immediate 
 experience, and, with objects of this class, others are 
 found connected. I see smoke ; I know its existence 
 by immediate experience ; I infer fire : this is known 
 to me by the connection fire has with smoke. 
 
 356. As the internal nature of objects is but little 
 known to us, we often find ourselves compelled to con- 
 sider them in dependence among themselves, either 
 because in many instances they are united, or because 
 some of them emanate from others. This fact, which 
 is a fundamental one in the sciences of observation, and 
 which we are constantly using in the regular course of 
 life, is one that is calculated to lead us into error. To 
 prevent that, the following rules are to be observed : — 
 
VARIOUS QJESTIONS. 116 
 
 BULKS ON COEXISTENCE AND SUCCESSION. 
 
 I. 
 
 357. The simultaneous existence of two or more 
 things, or their immediate succession, considered solely 
 in themselves, does not prove that one of them dependa 
 from tlie other. 
 
 We are constantly seeing things in coexistence and 
 succession that are in no way related. To be in one and 
 the same place, to exist at one and the same time, and 
 to exist in times immediately successive, are things 
 which are very distant from the relation of dependence. 
 
 II. 
 
 358. When a constant, unchanging experience shows 
 us that ^wo or more objects exist at one and the same 
 time, in &uch a way that, when one is presented, the other 
 is also presented, and that, when one is absent, the other 
 is also absent, — in a case like this we may unhesitat- 
 ingly judge that the objects have some connection 
 between them ; and, therefore, from the existence of one 
 we may legitimately infer the existence of the other. 
 
 With the presence of certain bodies coincides what 
 we call light and vision ; it little matters that we do 
 not know the internal nature of these phenomena : 
 their coexistence makes us sure of their relation. 
 
 III. 
 
 359. If between two objects there is indefectible 
 succession, so that, the first being given, the second is 
 always sure to follow it, and, the second being given, the 
 first is always present, — in such a case, it can be held 
 with certainty that the objects have some dependence 
 between them. 
 
 Heat applied to a caldron of water makes the water 
 
i 16 LOGia 
 
 boil. Men did not wait for the developments of science 
 to affirm that this movement of the water comes from the 
 fire. The lightning forks its way through the air, and, 
 in a moment after, the thunder-clap is heard : the con- 
 stant occurrence of these phenomena caused it o be be- 
 lieved that the first depended from the second, long 
 before the theory of electricity and the principle of the 
 transmission of sound were understood. 
 
 IV. 
 
 360. The dependence indicated by coexistence, or 
 succession, is not always direct from the objects them 
 selves : for dependence may come from a third or un 
 seen cause. 
 
 When a country has a certain fruit, it always has a 
 certain other one. This does not prove that the first 
 depends on the second, nor the the second on the first : 
 it only shows that the two fruits depend from a c?-use 
 which has produced them. When a certain disease is 
 common, a certain other disease is also common : this 
 does not establish the relation of cause and effect ; the 
 two diseases can be independent of each other, but de- 
 pendent, both of them, on one and the same cause. Two 
 persons meet at the same point, at the same hour for 
 many days : here there is no proof that the departure 
 of one has any relation with that of the other ; but the 
 two departures, although purely casual with respect to 
 each other, have still their proper cause ; such, for 
 instance, as a common necessity to be at business at a 
 common hour. 
 
 361. The reason by which we instinctively attribute 
 a connection, either mutual or not, to facts which con- 
 stantly coexist, or succeed to each other, rests on a 
 principle deeply engraved in our soul : where there ii 
 
VARIOUS QUESTIONS. IIT 
 
 order, where there is combination, there is a cause which 
 orders and combines. Pure chance is a word without 
 sense. 
 
 JUDGMENT ON THE HUMAN ACTS. 
 
 362. Judgment on the human acts is subject to rules 
 which are quite different from those that operate on the 
 phenomena of nature. Man, being endowed with free 
 will, conjectures upon his acts, hidden or yet to come, 
 cannot be subjected to rigorous calculation. Probable 
 rules, however, can be given on this point : — 
 
 PEOBABLE RULES ON THE HUMAN ACTS. 
 
 363. But little should be made of the virtue of most 
 men when it is exposed to a severe ordeal. 
 
 Strong passions, powerful interests, produce vehe- 
 ment impulses, which are resisted with great difficulty, 
 excepting where there is very elevated virtue ; and 
 this is found only in a few j and, therefore, they who 
 love danger, perish in it. 
 
 II. 
 
 364. The maxim, " Think what is lad and you wiU 
 not err^^ is inadmissible, not only from motives of 
 charity, but also from good logic. 
 
 It is evident that this maxim is not applicable in the 
 case of the good. And it is equivocal when applied to 
 the bad. A Uar, however great a liar he may be, lies 
 only when he has some interest or taste at stake. Hence 
 it is that if we compare his assertions among themselves, 
 it will always be found that he tells more truth than 
 falsehood. The drunkard passes more hours with his head 
 clear than muddled ; the dissolute indulge their passions 
 only in opportunity. It is, therefore, very hazardous 
 ko put down as bad the generality of human actionsi 
 
118 LOGIC. 
 
 Such a rule condemns as bad many acts that are not 
 bad in any degree. 
 
 m. 
 
 365 To conjecture on the conduct of a man in a 
 given situation, it is necessary to know his intelligence, 
 his disposition, his character, his morality, his interests, 
 and, in a word, every thing that might influence his 
 determination. Man, although endowed with free will, 
 is subject to various influences that contribute to decide 
 his will. To leave one of these unconsidered, is to 
 neglect a point in the problem. 
 
 IV. 
 
 366. We should not think that others would do as we 
 ourselves would do. 
 
 Disregarding this rule, we fall into errors grave and 
 frequent. We have a natural inclination to judge others 
 by ourselves : without observing it, we attribute to them 
 our ideas, affections, and character. The good man is 
 deceived by his goodness ; the bad man by his badness. 
 
 HUMAN AUTHORITY. 
 
 367. In many cases we are unable to know the truth 
 by ourselves, either immediately, or mediately ; and, in 
 consequence, we must use the testimony of men. Dis- 
 tance in time and place disconnects us from facts, and 
 we cannot develop them by argument : sometimes, 
 because they depend on human liberty, and sometimes, 
 because they proceed from causes of which we have no 
 knowledge. How can I know what happens at this 
 moment in Pekin or in any other far-off city ? If the 
 question refers to the free acts of man in those places, 
 it is impossible for me to know them, because they do 
 not depend on any necessary cause ; and if the question 
 U of natural occurrences, as, for instance, floods, 
 
VARIOUS QUESTIONS. 119 
 
 tempesiS; earthquakes, 1 am insufficiently acquainted 
 with the relations of the causes which operate in the 
 world to determine, a priori^ what effects they are pro- 
 ducing at the present time in such or such a part of the 
 globe. This is an illustration of the barrier distance 
 of place erects before our intelligence. And so as to 
 distance of time : it, too, impedes the knowledge of facts, 
 excepting where evident signs of them remain ; as when 
 iin abundance of lava proves a volcanic eruption, and as 
 numerous petrifactions and shells give evidence of the 
 previous presence of water. 
 
 368. To have a human testimony true, there must be 
 two conditions : that the witness himself is not deceived ; 
 and that he has no design to deceive his hearers. The 
 veracity and good faith of a narrator are little worth, if 
 he himself is deceived ; and the knowledge of a liar is 
 of no value, if he tells us the contrary of what he 
 knows. 
 
 RULES ON HUMAN AUTHOEITY. 
 I. 
 
 869. We should examine both the means at the 
 disposal of a narrator for finding the truth, and the 
 probability of all he says. 
 
 n. 
 
 370. In an equali^^y of circumstances, the ocular wit 
 Qess is to be preferred. 
 
 m. 
 
 371. In an equality of circumstances, and where the 
 witnesses are ocular, the witness who has no pail or 
 interest whatever in the matter at stake, is the one to 
 be preferred. 
 
120 LOGIC. 
 
 IV. 
 
 372. It 18 necessary to compare the testimony of « 
 witness with that of another who Ijas different opinion! 
 and interests. 
 
 V. 
 
 373. In narrations, it is necessary to carefully dis- 
 tinguish between the fact narrf«ted and the causes given 
 for it, between the results attributed to it, and the judg« 
 ment of the writers. 
 
 VI. 
 
 374. Anonymous witner^es deserve little confidence 
 
 vn. 
 
 375. Before reading a narration, it is very important 
 to know the situation, aad, especially, the circumstances. 
 of the narrator. 
 
 vm. 
 
 376. Posthumous works published by unknown or 
 uncertain agents, may be suspected of being apocryphal, 
 or of being altere*l. 
 
 IX. 
 
 377. Narrations founded on secret memoirs, or un 
 edited papers, deserve no more credit than is due to 
 the person wh j makes himself responsible for them. 
 
 X. 
 
 878. Ac^ ounts of hidden transactions, the secrets of 
 states, piqi ant anecdotes on the private life of celebrated 
 personages, histories of dark intrigues, and other such 
 things, should all be received with extreme suspicion. 
 
VARIOUS QUESTIONS. 131 
 
 XI. 
 
 379. In the matter of ancient, or very remote people, 
 but little credit is due to all that refers to the rijjhes of 
 the country, to the number of its inhabitants, to the 
 treasures of the monarchs, to the religious ideas, and to 
 the domestic customs. 
 
 XII. 
 
 380. Much confidence should not be placed in the 
 narrations of travellers who have not remained long in 
 the country they describe. 
 
 Section IV. — Questions on the Nature of Things. 
 
 381. In questions connected with the internal nature 
 of things, the following rules should be kept in sight :— 
 
 RULES ON THE INTERNAL NATURE OF THINGS. 
 
 382. The internal nature of things is frequently un^ 
 known to us ; we know of it but little, and that littlo 
 imperfectly. 
 
 The truth of this observation is all the better known, 
 the better our studies are made : the result of the most 
 assiduous and profound labors is the conviction of our 
 own ignorance. 
 
 383. The best resolution of many questions is the 
 knowledge that it is impossible to resolve them. 
 
 Men lose much time in disputing problems that rest 
 on nothing. There are questions in the world that 
 make great noise, and that may be compared to this : 
 ihe number of the stars is equal, or unequal 
 
 ni. 
 
 384. As things differ much among themselves, in 
 tkeir nature, in their properties, in their relations, m 
 
 6 
 
122 LOGIC. 
 
 the modes of examining them^ and the methods of 
 reasoning on them, should, also, be very diiFerent. To 
 apply the mathematical methods to the political and 
 moral sciences, is to fall into grave errors ; and to 
 judge the merit of a literary work by a metaphysical 
 or dialectical analysis, is like dissecting a living body. 
 
 IV. 
 
 385. In the consideration of necessary tilings^ it is 
 important to keep in view the relations of pure ideas. 
 In the sciences that are concerned with nature, it is 
 necessary to be founded on observation. When it is 
 man we consider, the human heart should be .studied. 
 In moral questions, we must have with us the eternal 
 principles of reason, illustrated by universal trfldition 
 and, above all, by the Christian religion. 
 
 386. All rules avail nothing if we have not a profoimd 
 love for truth, and if we do not know how to silence our 
 passions so as to see in things that which is really in 
 them, and not that which we desire they should contain. 
 
 Section V. — The Use of the Hypothesis, 
 
 387. The Hypothesis is a supposition of which we 
 make use to explain a thing. A business, found to be 
 in a good state for a long time, is suddenly ruined, and 
 the cause of the misfortune is unknown ; still, conjecture 
 is made, and the disaster gets explanation in the bad 
 will jof an enemy, who had the power in his hands to 
 effect it. This is a hypothesis. In explaining natural 
 phenomena, where the cause is unknown, hypothesis u 
 ofiten used. Works on mechanics show this. 
 
VARIOUS' QUESTIONS. 123 
 
 888. The employment of hypothesis, when used with 
 judgment, is beneficial ; for it exercise* the understand- 
 ing by accustoming it to reduce variety to unity, and 
 also because the knowledge of possible causes, which it 
 confers, often leads to real causes. But it must be 
 remembered that the hypothesis, by itself alone, proven 
 nothing in favor of reality. To say this could have 
 happened in such a manner, and then to lay down that 
 it has so happened, is to make an illegitimate conclusion. 
 Thus, in the preceding example, the business could in 
 fact have been ruined by the bad will of an enemy ; but 
 this does not exclude many other causes, as the inju- 
 dicious officiousness of a friend, or the superior activity 
 of a rival, and so on. 
 
 389. Suppositions, when they are ingenious, and, 
 especially, if they have some resemblances of probability, 
 frequently deceive us, leading us into grave errors : and 
 this both in the study of the sciences and in the common 
 practice of life. li could have happened thus ; therefore, 
 it has happened thus : this is desperate argument, and 
 yet it is in common use as an unanswerable proof. 
 
 390. From possibility to reality there is a long dis- 
 tance. We should seek not that which can be, but 
 that which is. In matters independent of our under- 
 standing, the observation of facts, such as they are in 
 themselves, is essential ; and, if these facts are hidden 
 from us, it is better to know and to confess our ignorance 
 than to delude ourselves by taking for realities the pro 
 ductions of our fancy. 
 
 Section VI. — Synthesis and Analysis, 
 
 891. When in operations we pass from the simple to 
 the compound, the method is called synthetical ; when 
 the proceeding is the opposite if this, the method if 
 
124 LOGIC. 
 
 analytical. If we take separately the different parts of 
 a watch, and after considering them first in themsMjlves. 
 and then in the relations they have to each other, we gc 
 on putting the article together, the method is syntheti- 
 cal. On the other hand, it taking the watch already con- 
 structed, we examine the movement as a whole, inves- 
 tigate the relations of the parts among themselves, coming 
 finally to the knowledge of the structure of each one oi 
 them, and of the functions it performs in the watch, — then 
 we have the analytical method. Beginning at the first 
 principles of geometry , and amplifying them successively 
 by means of demonstrations, we reach the formation of 
 the curve, and the knowledge of its nature and pro- 
 perties : this method is synthetical. Considering the 
 curve in itself, and decomposing it in diff'enmt ways., 
 leads also to the knowledge of its nature and properties: 
 here we have the analytical method. 
 
 392. It is sometimes asked which of these methods 
 is to be preferred : and the common answ€ r is, thai 
 synthesis is preferable for instruction, and analysis foi 
 investigation and invention. This is a judicious solu- 
 tion : for the master who knows beforehand the poini 
 to which he wiskes to conduct his pupil, can begin by 
 the simple to come to the compound, which iij already 
 known. But, in investigating truth, objects must be 
 taken as they are presented, and it is clear I hat they 
 are presented not decomposed into parts, but forming 
 a whole. 
 
 393. But no exact limits can be drawn betw een these 
 methods: utility and necessity are constantly uniting 
 them. One is often substituted for the other. The 
 preference between them depends on circumstances. 
 
 894. When the synthetic method is foUovQd, tht 
 
VARIOUS QUESTIOIs'S. 125 
 
 mania of composing without sufficient elements must 
 be avoided; and, in the analytical way, it is necessary 
 to remember tliat too great a separation of parts, en- 
 dangers the just conception of their relation with the 
 whole. 
 
 Sectio:n" VII. — Necessity of Labor, 
 
 395. Man has many happy inspirations which cost 
 no toil: but, in general, he must labor, or continue 
 to live in ignorance. Even the spontaneous inspi- 
 rations themselves, as a rule, come only to those 
 who have cultivated their talents with great assiduity. 
 Without activity the mind does not develop; but, like 
 the body which remains unemployed, it feels its forces 
 diminishing, and it leads a languid, crawling sort of 
 existence. Some believe that the great geniuses are 
 lazy. A great error ! All great men have been distin- 
 guished by indefatigable activity: tliisis a necessary con- 
 dition for their greatness; without it they would not be 
 great. Vanity sometimes makes men conceal the labor a 
 work costs them. But it is certain that, without much 
 labor, it is very little of what is excellent that can be 
 accomplished. Those who have extraordinary facility 
 have acquired it by constant exercise. It is a puerile 
 vanity that much can be done with little toil. No one 
 should be ashamed of the conditions imposed on the 
 human race ; and one of these is, that there is no 
 progress without labor. 
 
 To labor with profit, it is proper to keep in view some 
 observations on reading, conversation, and meditation. 
 
 Sectioi^ Ylll.— Observations on Beading. 
 
 396. In reading, there are two essentials : to select 
 good books, and to read them well, 
 
 397. Books that mislead the understanding, or cor-^ 
 
126 LOGIC. 
 
 rupt the heart, should never be read. Irreligious and 
 immoral readings conduct to no science ; on the con- 
 trary, they are a spring of frivolous superficiality. 
 
 398. We should read authors whose names are 
 generally known and respected: this saves much time, 
 and is pregnant with advancement. Eminent writers 
 teach not only by what they say, but also by what 
 they make us think. The mind is nourished by the 
 doctrine they communicate, and it develops and unfolds 
 by the reflections which they inspire. Of two men, 
 one mediocre, the other eminent, — who would prefer to 
 consult the mediocre ? 
 
 399. No art, no science should be studied by 
 dictionaries or encyclopasdias. It is necessary to begin 
 at elemental works in order to find fruit in the study of 
 those that are far advanced. Dictionaries and ency- 
 clopaedias are good as books of reference, but not for 
 sounding things to the bottom. 
 
 400. No7i multa, seel mulium. To read mnch, but 
 not many books, is an excellent rule. Reading is like 
 food: the nutrition is in proportion, not to the quantity 
 consumed, but to the quantity digested. 
 
 401. Reading should be slow, attentive, reflective. 
 It should be often interrupted in order to reflect on 
 what has been perused. By this means the substance 
 of the author becomes our own; and an act is performed 
 in the understanding like that which takes place in the 
 nutritive functions of the person. 
 
 402. It is often said that, in reading, it is best to keep 
 a pen in the hand, so as to make notes of striking points. 
 This, undoubtedly, is a wise rule: but, in regard to it. 
 
VARIOUS (QUESTIONS. 1^^ 
 
 tL* following hints may be kept in view : first, it rtx« 
 poses us to the danger of putting down many useless 
 remarks, and, therefore, to a waste of time which coidd 
 be more profitably employed in reading; second, by 
 putting every thing on paper, the growth of the memory 
 is interfered with : the best note-book is the head : 
 it neither mislays papers, nor confuses them; third, 
 proper names and dates had better not be entirely in- 
 trusted to the memory. 
 
 403. The immoderate desire of universality is a 
 fountain of ignorance. Wishing to know all, ends in 
 knowing nothing. It is very few men that are born 
 with talents, sufficient to enter on all the sciences : 
 hence, it is very important to possess even one science 
 to the foundation. And, therefore, our studies should 
 always be undertaken after a due consideration of our 
 capacities, of the time at our disposal, and of the pro- 
 fession we are to pursue. What is the use of a 
 knowledge of botany to a soldier, if he is ignorant of the 
 art of war? What profit would geometry be to an 
 advocate, if he were unacquainted with jurisprudence I 
 
 Section IX. — Conversation and Dispute. 
 
 404. Conversation with men is a great means for in- 
 creasing our knowledge. Discussion is a fountain of light, 
 provided we suppress personal vanity, the pai*tiality of 
 disposition, and avoid the dangers of giving offence. 
 
 405. It is worthy of remark that, in the warmth of 
 discussion, and sometimes even in the mild activity of 
 tranquil conversation, thoughts occur to us which we 
 never before experienced. The difficulties of our 
 opponent, tlie observations of a friend, the doubts of the 
 indifferent, even the deficienciea of the ignorant, ar» 
 
1 2R LOGIC. 
 
 )flen the means of shedding new light on disputed 
 tjaestions. The human intellects have the faculty of 
 Iccundizing each other. 
 
 406. Unfortunately, however, men fall with too much 
 frequency into the faults pointed out above. All of ua 
 can attest cases in which previously formed judgments 
 were stubbornly held to the last ; in which the aim was, 
 not to find out the truth, but to fight a battle and gain 
 a victory, and in which the pride of the contestants 
 became exalted and their words offensive. And thus 
 it too often is, that that which ought to be an association 
 where each one could contribute his assistance as to a 
 common fund with the object of discovering the truth, 
 is converted into a literary arena where passion pre- 
 dominates. 
 
 407. The mere spirit of dispute is to be avoided. It 
 is better to be contented with silence than to go into 
 discussions from which nothing can be hoped in favor 
 of the truth, even when propositions are put forth which 
 could be easily undone. This prudence in escaping 
 noisy contentions is conformable to good morals, to good 
 education, and it saves much precious time to be 
 employed in useful operations. 
 
 408. But, for all this, it is necessary to look for in- 
 tercourse with judicious and intellectual persons. It 
 is incredible what benefit arises from conversing with 
 others on things that have engaged our study. By 
 communication of this nature the mind unfolds itself, 
 vivifies itself, recovers its power weakened in solitude, 
 gains knowledge of its errors, rectifies its equivocations, 
 confirms itself in the possession of truth acquired, dis- 
 covers new ways for more acquisition : in a word, it 
 gatbert Xhp fruit of (he labors of its interlocHtor, in turn 
 
VARIOUS QUESTIONS. 129 
 
 ommunicates its own, it gives and receives, it learnt, 
 
 nd it gives gratification. 
 
 Section X. — Meditation, 
 
 409. Meditation is the intellectual labor by which we 
 endeavor to know a thing to the foundation. It is clear 
 that it would be a sterile act, were there no ideas on 
 which to fix it. Hence, to meditate with fruit, it ii 
 necessary to have a supply of materials, acquired through 
 reading, conversation, and observation. 
 
 410. Intercourse with thinking men, and the reading 
 of profound authors^ insensibly accustom us to meditate. 
 V\^e should do all in our power to generate this custom 
 in our minds, by contracting the habit of reflecting on 
 every thing ofi'ered to our consideration. Here we include 
 the pursuits of business, as well as the subjects of science 
 rnd letters : many errors, practical as well as specula- 
 t've, have their birth in deficient reflection. There are 
 men who read much, and meditate none at all on what 
 tlu'y read. The heads of such persons are depositories 
 of ^oreign thoughts, which contain nothing belonging to 
 themselves ; anu which even in their best moments 
 betray a borrowed Intellectuality. It must be remem- 
 bered that the fruit oF study is found in proportion, not 
 alone with study it«^olf, but also with the method of 
 study. Then again, uiere are others in the manage- 
 meiit of business, sometimes of the highest importance, 
 who scarcely ever properly reflect on the nature of 
 their responsibility. Tbis is proceeding without plan, 
 without foresight of what may happen, and leads to di» 
 Mtftr* that, no do ibt, covdd be easily obviated. 
 
130 LOGIC. 
 
 SectioK XI. — Practical Questions, 
 
 411. The practical acts of the understanding are 
 those which direct our actions. What should I do to 
 manifest my gratitude ? To what sacrifice does friend- 
 ship oblige me ? What is the way in which to admin- 
 ister this or that responsibility? How should the 
 motive powers be combined in a machine so as to make 
 it exercise its functions ? These are pra(;tical questions. 
 It will be seen that they are divided into two classes : 
 to the class of free action, and to that of actions that 
 fall. under the necessary laws. 
 
 412. When man wishes to operate, he always, propo- 
 ses to effect some end. Without this condition the will 
 does not move. The object of an act is to accomplish 
 a proposed end. Hence, in every operation it is essen- 
 tial to consider the end and the means. 
 
 413. The end of all acts ought to be normal. Every 
 end contrary to morality, should be inexorably aban- 
 doned. Nothing, either in art or science, can author- 
 ize the design of bad ends. The immoral, by the very 
 fact that it is immoral, is deficient in truth and beauty. 
 Truth and beauty do not really belong to immoral 
 things. 
 
 414. It is not enough that the end is not immoral; 
 it should be also an end that properly corresponds with 
 the agent and with circumstances. The end ought to 
 be proportioned to the means. Aspiring to an end, 
 without means to realize it, is a waste of time. 
 
 415. The circulation of external means is less diffi- 
 cult than that of internal means. The former are not 
 m.ide use of without the latter; and, precisely, it is as 
 
VARIOUS QUESTIOKb. 131 
 
 to the due knowledge of the latter the greatest difficulty 
 is experienced. Profoundly wise was the saying of the 
 Greeks — " Know yourself." 
 
 41G. In measuring our forces, we should guard, on 
 one side, against presumption, and, on the other, against 
 pusillanimity. Presumption leads us to undertakings 
 that are beyond our power ; but pusillanimity pre- 
 vents us from employing the capacity we possess; and, 
 assisted by laziness, one of the most general of the 
 human vices, it diseases activity, and makes men 
 inferior to themselves. 
 
 417. If a case is urgent, and we feel ourselves under 
 the influence of a passion, we should make an effort 
 to suppose ourselves in a state free of that passion. This 
 act, by the very fact that it excites reflection, calms the 
 passions, and enlightens the understanding, and then 
 we may hope to operate with success. 
 
 418. The means should he moral. The end does not 
 justify the means : it is never lawful to commit a bad 
 action, however holy may be the end which we have 
 in view. 
 
 419. The passions are good auxiliaries, when they 
 are directed by reason and morals : then they inspire 
 the understanding, and give firmness and energy to 
 the will. 
 
 REC APITULATIOIf . 
 
 420. A deep love for truth ; a fixed selection of 
 vocation ; indefatigability in labor ; an attention, firm 
 sustained^ and accommodated to objects and circum- 
 
132 LOGIC. 
 
 stances; an acquired practice in the exercise of the 
 faculties in accordance with the matter that engages us ; 
 knowledge of our capacity, without either presumption 
 or pusillanimity ; command over ourselves, in subjecting 
 the passions to the will, and the will to reason and 
 morals : — here are recapitulated all the means for think- 
 ing well ; here are condensed the rules of logic. 
 
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