DUKE UNIVERSITY LIBRARY NEWMAN COLLECTION PRESENTED BY RUTH GALLERT NEWMAN IN MEMORY OF JAMES R. NEWMAN PERKINS LIBRARY Duke Universitj Rare Books 9 10 / c n 11 12 _/ I f n «/ V 13 / 14 a 15 16 COLOURS FOR COUNTERS. See, the Sun is overhead, Shining on us, full and RED! Now the Sun is gone away, And the empty sky is GREY! y- X X y THE GAME LOGIC CWs.r\t* 'u>1<1 LEWIS CARROLL ae PRICE THREE SHILLINGS ILontioit MACMILLAN AND CO. AND NEW YORK 1887 IAU Rights reserved.] Richard Clay and Sons, london and bungay. c C0 mg Cfexlir-J^runtr* 31 cJjatm in toain ; for neber again, 3H keenly as mp dance 3[ fcenti, 223iII iHemorp, eoUTiess cop, (EEmboUp for mp jog Departed tiaps, nor let me &ic|? to reati in toery Ueeti ®fjp spirit, stoeetest JFrienti ! &o map ti>e stream of Hife's lone nream JFIoto Gently ontoarti to its enU, S2ait|? many a flotoeret cap, gUoton its toillotoy toay : fElay no sici) tier, no care perpler, iBp losing little JFrienti ! NOTA BENE. With eacli copy of this Book is given an Envelope, containing a Diagram (similar to the frontis- piece) on card, and nine Counters, four red and five grey. The Envelope, &c. can be had separately, at 3d. each. The Author will be very grateful for suggestions, especially from be- ginners in Logic, of any alterations, or further explanations, that may seem desirable. Letters should be- addressed to him at "29, Bedford Street, Covent Garden, London." PREFACE " There foam'd rebellious Logic, gagg'd and bound." rP HIS Game requires nine Counters — four of one colour and five of another : say four red and five grey. Besides the nine Counters, it also requires one Player, at least. I am not aware of any Game that can be played with less than this number : while there are several that require more : take Cricket, for instance, which requires twenty-two. How much easier it is, when you want to play a Game, to find one Player than twenty-two. At the same time, though one Player is enough, a good deal more amusement may be got by two working at it together, and correcting each other's mistakes. A second advantage, possessed by this Game, is that, besides being an endless source of amusement (the number of arguments, that may be worked by it, being infinite), it will give the Players a little instruction as well. But is there any great harm in that, so long as you get plenty of amusement ] CONTENTS. Chapter Page I. NEW LAMPS FOR OLD. § 1. Propositions 1 § 2. Syllogisms 20 § 3. Fallacies 32 II. CROSS QUESTIONS. § 1. Elementary 37 § 2. Half of Smaller Diagram. Propositions to he represented 40 § 3. Do. Symbols to be interpreted ... 42 § 4. Smaller Diagram. Propositions to be represented ...... 44 § 5. Do. Symbols to be interpreted ... 46 § 6. Larger Diagram. Propositions to be represented ...... 48 § 7. Both Diagrams to be employed . . . 51 III. CROOKED ANSWERS. § 1. Elementary 55 § 2. Half of Smaller Diagram. Propositions represented 59 § 3. Do. Symbols interpreted . . . . 61 § 4. Smaller Diagram. Propositions represented. 62 § 5. Do. Symbols interpreted .... 65 § 6. Larger Diagram. Propositions represented. 67 § 7. Both Diagrams employed .... 72 IV. HIT OR MISS 80 CHAPTER I. NEW LAMPS FOR OLD. " Light come, light go." § 1. Propositions. " Some new Cakes are nice." ' ; No new Cakes are nice/' " All new Cakes are nice." There are three 'Propositions' for you the only three kinds we are going to use in this Game : and the first thing to be done is to learn how to express them on the Board. Let us begin with " Some new Cakes are nice." But, before doing so, a remark has to be made one that is rather important, and by no means easy to understand all in a moment : so please to read this very carefully. 2 NEW LAMPS FOB OLD. [Ch. I. The world contains many Things (such as "Buns", "Babies", "Beetles", "Battledores", &c.) ; and theC Things possess many Attributes (such as "baked", "beautiful", "black", "broken", &c. : in fact, what- ever can be " attributed to ", that is " said to belong to ", any Thing, is an Attribute). Whenever we wish to mention a Thing, we use a Substantive : when we wish to mention an Attribute, we use an Adjective. People have asked the question " Can a Thing exist without any Attributes belonging to it ? " It is a very puzzling question, and I'm not going to try to answer it : let us turn up our noses, and treat it with con- temptuous silence, as if it really wasn't worth noticing. But, if they put it the other way, and ask "Can an Attribute exist without any Thing for it to belong to ? ", we may say at once " No : no more than a Baby could go a railway-journey with no one to take care of it ! " You never saw " beautiful " floating about in the air, or littered about on the floor, without any Thing to be beautiful, now did you ? And now what am I driving at, in all this long rigmarole ? It is this. You may put " is " or " are " between the names of two Things (for example, " some Pigs are fat Animals "), or between the names of two Attributes (for example, "pink is light-red"), and in each case it will make good sense. But, if you put " is " or " are " between the name of a Thing and the name of an Attribute (for example, "some Pigs are § 1.] PROPOSITIONS. 3 pink "), you do not make good sense (for how can a /Jhing be an Attribute ?) unless you have an under- standing with the person to whom you are speaking. And the simplest understanding would, I think, be this that the Substantive shall be supposed to be repeated at the end of the sentence, so that the sen- tence, if written out in full, would be " some Pigs are pink (Pigs)". And now the word " are " makes quite good sense. Thus, in order to make good sense of the Proposition " some new Cakes are nice ", we must suppose it to be written out in full, in the form " some new Cakes are nice (Cakes) ". Now this contains two ' Terms ' " new Cakes " being one of them, and " nice (Cakes) " the other. " New Cakes," being the one we are talking about, is called the ' Subject ' of the Proposition, and " nice (Cakes) " the ' Predicate \ Also this Proposition is said to be a ' Particular ' one, since it does not speak of the ichole of its Subject, but only of a part of it. The other two kinds are said to be ' Universal \ because they speak of the whole of their Subjects the one denying niceness, and the other asserting it, of the ivhole class of "new Cakes". Lastly, if you would like to have a definition of the word ' Proposition ' itself, you may take this : — " a sentence stating that some, or none, or all, of the Things belonging to a certain class, called its 'Subject', are also Things be- longing to a certain other class, called its ' Predicate ' ". B 2 4 NEW LAMPS FOR OLD. [Ch. I. You will find these seven words Proposition, Attribute, Term, Subject, Predicate, Particular, Universal charmingly useful, if any friend should happen to ask if you have ever studied Logic. Mind you bring all seven words into your answer, and your friend will go away deeply impressed 'a sadder and a wiser man '. Now please to look at the smaller Diagram on the Board, and suppose it to be a cupboard, intended for all the Cakes in the world (it would have to be a good large one, of course). And let us suppose all the new ones to be put into the upper half (marked ' x'), and all the rest (that is, the not-new ones) into the lower half (marked 'x"). Thus the lower half would contain elderly Cakes, aged Cakes, ante-diluvian Cakes if there are any : I haven't seen many, my- self and so on. Let us also suppose all the nice Cakes to be put into the left-hand half (marked l y'), and all the rest (that is, the not-nice ones) into the right-hand half (marked ' y' '). At present, then, we must understand x to mean " new ", x' " not-new ", y " nice ", and y' " not-nice." And now what kind of Cakes would you expect to find in compartment No. 5 ? It is part of the upper half, you see ; so that, if it has any Cakes in it, they must be new: and it is part § 1.] PROPOSITIONS. 5 of the left-hand half ; so that they must be nice. Hence if there are any Cakes in this compartment, they must have the double ' Attribute ' " new and nice " : or, if we use letters, they must be " x y" Observe that the letters x, y are written on two of the edges of this compartment. This you will find a very convenient rule for knowing what Attributes belong to the Things in any compartment. Take No. 7, for instance. If there are any Cakes there, they must be " x' y ", that is, they must be " not-new and nice." Now let us make another agreement that a red counter in a compartment shall mean that it is ( oc- cupied \ that is, that there are some Cakes in it. (The word ' some/ in Logic, means ' one or more ' : so that a single Cake in a compartment would be quite enough reason for saying " there are some Cakes here"). Also let us agree that a grey counter in a compartment shall mean that it is ' empty ', that is, that there are no Cakes in it. In the following Diagrams, I shall put ' 1 ' (meaning ' one or more ') where you are to put a red counter, and * ' (meaning ' none ') where you are to put a grey one. As the Subject of our Proposition is to be " new Cakes", we are only concerned, at present, with the upper half of the cupboard, where all the Cakes have the attribute x, that is, " new." 6 NEW LAMPS FOR OLD. [Ch. I. Now, fixing our attention on this upper half, sup- pose we found it marked like this, 1 that is, with a red counter in No. 5. What would this tell us, with regard to the class of " new Cakes " ? Would it not tell us that there are some of them in the x ^-compartment ? That is, that some of them (besides having the Attribute x, which belongs to both compartments) have the Attribute y (that is, "nice"). This we might express by saying " some ^-Cakes are y- (Cakes) ", or, putting words instead of letters, " Some new Cakes are nice (Cakes)", or, in a shorter form, " Some new Cakes are nice ". At last we have found out how to represent the first Proposition of this Section. If you have not clearly understood all I have said, go no further, but read it over and over again, till you do understand it. After that is once mastered, you will find all the rest quite easy. It will save a little trouble, in doing the other Propositions, if we agree to leave out the word " Cakes " altogether. I find it convenient to call the whole class of Things, for which the cupboard is in- tended, the ' Universe! Thus we might have begun this business by saying " Let us take a Universe of Cakes." (Sounds nice, doesn't it ?) § !•] PROPOSITIONS. Of course any other Things would have done just as well as Cakes. We might make Propositions about " a Universe of Lizards ", or even " a Universe of Hornets". (Wouldn't that be a charming Universe to live in ? ) So far, then, we have learned that 1 means " some x and y" i. e. " some new are nice." I think you will see, without further explanation, that means " some x are y' ," i. e. " some new are not-nice." Now let us put a grey counter into No. 5, and ask ourselves the meaning of This tells us that the x ^-compartment is empty, which we may express by " no x are y ", or, " no new Cakes are nice ". This is the second of the three Propositions at the head of this Section. In the same way, j would mean " no x are y '," or, " no new Cakes are not-nice/ NEW LAMPS FOR OLD. [Ch. I. What would you make of this, I wonder ? i > ' 1 ' 1 ! I hope you will not have much trouble in making out that this represents a double Proposition : namely, " some x are y, and some are y'" i. e. " some new are nice, and some are not-nice/' The following is a little harder, perhaps : — This means " no x are y, and none are ?/," i. e. " no new are nice, and none are not-nice " : which leads to the rather curious result that " no new exist," i.e. " no Cakes are new." This is because " nice " and " not-nice " make what we call an 'exhaustive' division of the class "new Cakes " : i. e. between them, they exhaust the whole class, so that all the new Cakes, that exist, must be found in one or the other of them. And now suppose you had to represent, with counters, the contradictory to " no Cakes are new ", which would be " some Cakes are new ", or, putting letters for words, " some Cakes are x ", how would you do it ? This will puzzle you a little, I expect. Evidently you must put a red counter someivhcrc in the cc-half of the cupboard, since you know there are some new Cakes. But you must not put it into the left-hand compartment, since you do not know them to be nice : nor may you put it into the right-hand one, since you do not know them to be not-nice. § 1.] PROPOSITIONS. 9 What, then, are you to do ? I think the best way- out of the difficulty is to place the red counter on the division-line between the #2/-compartment and the ^'-compartment. This I shall represent (as / always put ' 1 ' where you are to put a red counter) by the diagram Our ingenious American cousins have invented a phrase to express the position of a man who wants to join one or other of two parties such as their two parties ' Democrats ' and ' Republicans ' but can't make up his mind which. Such a man is said to be " sitting on the fence." Now that is exactly the position of the red counter you have just placed on the division- line. He likes the look of No. 5, and he likes the look of No. 6, and he doesn't know which to jump down into. So there he sits astride, silly fellow, dangling his legs, one on each side of the fence ! Now I am going to give you a much harder one to make out. What does this mean ? 1 This is clearly a double Proposition. It tells us, not only that "some x are y," but also that "no x are not yT Hence the result is "all x are y," i. e. " all new Cakes are nice ", which is the last of the three Propositions at the head of this Section. 10 NEW LAMPS FOR OLD. [Ch. I. We see, then, that the Universal Proposition " All new Cakes are nice " consists of two Propositions taken together, namely, " Some new Cakes are nice," and " No new Cakes are not-nice." In the same way 1 would mean " all x are y' ", that is, " All new Cakes are not-nice." Now what would you make of such a Proposition as " The Cake you have given me is nice " ? Is it Particular, or Universal ? " Particular, of course," you readily reply. " One single Cake is hardly worth calling ' some/ even." No, my dear impulsive Reader, it is ' Universal \ Remember that, few as they are (and I grant you they couldn't well be fewer), they are (or rather ' it is ') all that you have given me ! Thus, if (leaving ' red ' out of the question) I divide my Universe of Cakes into two classes the Cakes you have given me (to which I assign the upper half of the cupboard), and those you haven t given me (which are to go below) I find the lower half fairly full, and the upper one as nearly as possible empty. And then, when I am told to put an upright division into each half, keeping the nice Cakes to the left, and the not-nice ones to § 1.] PROPOSITIONS. 11 the right, I begin by carefully collecting all the Cakes you have given me (saying to myself, from time to time, " Generous creature ! How shall I ever repay such kindness ? "), and piling them up in the left-hand com- partment. And it doesn't take long to do it ! Here is another Universal Proposition for you. " Bar- zillai Beckaleo-or i s an honest man." That means " All the oo Barzillai Beckaleggs, that I am now considering, are honest men." (You think I invented that name, now don't you ? But I didn't. It's on a carrier's cart, somewhere down in Cornwall.) This kind of Universal Proposition (where the Subject is a single Thing) is called an ' Individual ' Proposition. Now let us take "nice Cakes" as the Subject of our Proposition : that is, let us fix our thoughts on the left- hand half of the cupboard, where all the Cakes have the attribute y, that is, " nice." Suppose we find it marked like this : — What would that tell us ? I hope that it is not necessary, after explaining the horizontal oblong so fully, to spend much time over the upright one. I hope you will see, for yourself, that this means " some y are x ", that is, " Some nice Cakes are new." " But," you will say, " we have had this case before. You put a red counter into No. 5, and you told us it meant 12 NE IV LAMPS FOR OLD. [Ch. I. ' some new Cakes are nice ' ; and now you tell us that it means ' some nice Cakes are new ' ! Can it mean both ? " The question is a very thoughtful one, and does you great credit, dear Eeader ! It does mean both. If you choose to take x (that is, "new Cakes") as your Subject, and to regard No. 5 as part of a horizontal oblong, you may read it " some x are y ", that is, " some new Cakes are nice " : but, if you choose to take y (that is, " nice Cakes ") as your Subject, and to regard No. 5 as part of an upright oblong, then you may read it " some y are x ", that is, " some nice Cakes are new ". They are merely two different ways of expressing the very same truth. Without more words, I will simply set down the other ways in which this upright oblong might be marked, adding the meaning in each case. By comparing them with the various cases of the horizontal oblong, you will, I hope, be able to understand them clearly. You will find it a good plan to examine yourself on this table, by covering up first one column and then the other, and ' dodging about ', as the children say. Also you will do well to write out for yourself two other tables one for the lower half of the cupboard, and the other for its right-hand half. And now I think we have said all we, need to say about the smaller Diagram, and may go on to the larger one. § ij PROPOSITIONS. 13 Symbols. Meanings. ■ Some y are x' ; i. e. Some nice are not-new. 1 No y are x ; i. e. No nice are new. [Observe that this is merely another way of expressing " No new are nice."] No y are x' ; i. e. No nice are not-new. 1 Some y are x, and some are x' ; i. e. Some nice are new, and some are 1 not-new. No y are x, and none are x' \ i.e. Ko j/ exist ; i. e. No Cakes are nice. 1 All y are x ; i. e. All nice are new. 1 All y are x' ; i. e. All nice are not-new. 14 NEW LAMPS FOR OLD. [Ch. I. This may be taken to be a cupboard divided in the same way as the last, but also divided into two portions, for the Attribute m. Let us give to m the meaning " wholesome " : and let us supj>ose that all ivholesomc Cakes are placed inside the central Square, and all the unwholesome ones outside it, that is, in one or other of the four queer-shaped outer compartments. We see that, just as, in the smaller Diagram, the Cakes in each compartment had two Attributes, so, here, the Cakes in each compartment have three Attri- butes : and, just as the letters, representing the two Attributes, were written on the edges of the compart- ment, so, here, they are written at the comers. (Observe that m' is supposed to be written at each of the four outer corners.) So that we can tell in a moment, by looking at a compartment, what three Attributes belong to the Things in it. For instance, take No. 12. Here we find x, y', m, at the corners : so we know that the Cakes in it, if there are any, have the triple Attribute, * xy'm \ that is, " new, not-nice, and wholesome." Again, take No. 16. Here we find, at the corners, x, y\ m : so the Cakes in it are " not-new, not-nice, and unwholesome." (Remarkably untempting Cakes !) It would take far too long to go through all the Propositions, containing x and y, x and m m and y and m, which can be represented on this diagram (there are ninety-six altogether, so I am sure you will excuse me !) § 1.] PROPOSITIONS. 15 and I must content myself with doing two or three, as specimens. You will do well to work out a lot more for yourself. Taking the upper half by itself, so that our Subject is " new Cakes ", how are we to represent " no new Cakes are wholesome " ? This is, writing letters for words, "no x are m" Now this tells us that none of the Cakes, belonging to the upper half of the cupboard, are to be found inside the central Square: that is, the two compartments, No. 11 and No. 12, are empty. And this, of course, is repre- sented by And now how are we to represent the contradictory Proposition " some x are m " ? This is a difficulty I have already considered. I think the best way is to place a red counter on the division-line between No. 11 and No. 12, and to understand this* to mean that one of the two compartments is ' occupied/ but that we do not at present know which. This I shall represent thus : — 16 NEW LAMPS FOR OLD. [Ch. I Now let us express " all x are m" This consists, we know, of two Propositions, " Some x are m" and " No x are m'." Let us express the negative part first. This tells us that none of the Cakes, belonging to the upper half of the cupboard, are to be found outside the central Square : that is, the two compartments, No. 9 and No. 10, are empty. This, of course, is represented by I But we have yet to represent " Some x are m" This tells us that there are some Cakes in the oblong con- sisting of No. 11 and No. 12: so we place our red counter, as in the previous example, on the division-line between No. 11 and No. 12, and the result is - Now let us try one or two interpretations. What are we to make of this, with regard to x and y ? 1 1 § 1-] PROPOSITIONS. 17 This tells us, with regard to the # /-Square, that it is wholly ' empty ', since both compartments are so marked. With regard to the ^-Square, it tells us that it is i occupied \ True, it is only one compartment of it that is so marked; but that is quite enough, whether the other be 'occupied' or 'empty', to settle the fact that there is something in the Square. If, then, we transfer our marks to the smaller Diagram, so as to get rid of the m-subdivisions, we have a right to mark it 1 which means, you know, " all x are y." The result would have been exactly the same, if the given oblong had been marked thus : — 1 1 1 o 1 Once more : how shall we interpret this, with regard to x and y ? 1 This tells us, as to the ^-Square, that one of its compartments is ' empty '. But this information is c 18 NEW LAMPS FOR OLD. [Ch. I. quite useless, as there is no mark in the other com- partment. If the other compartment happened to be ( empty ' too, the Square would be ' empty ' : and, if it happened to be 'occupied', the Square would be ' occupied \ So, as we do not know which is the case, we can say nothing about this Square. The other Square, the ^'-Square, we know (as in the previous example) to be ' occupied \ If, then, we transfer our marks to the smaller Diagram, we get merely this : — 1 which means, you know, " some x are y'" These principles may be applied to oblongs. For instance, to represent " all y' are m' " we should mark the right -hand upright oblong (the one that has the attribute y') thus : — and, if we were told to interpret the lower half of the cupboard, marked as follows, with regard to x and y, 1 § 1.] PROPOSITIONS. 19 we should transfer it to the smaller Diagram thus, 1 ° and read it " all x are y" Two more remarks about Propositions need to be made. One is that, in every Proposition beginning with " some " or " all ", the actual existence of the * Subject ' is asserted. If, for instance, I say " all misers are selfish," I mean that misers actually exist. If I wished to avoid making this assertion, and merely to state the law that miserliness necessarily involves selfishness, I should say "no misers are unselfish" which does not assert that any misers exist at all, but merely that, if any did exist, they vjould be selfish. The other is that, when a Proposition begins with " some " or " no ", and contains more than two Attributes, these Attributes may be re-arranged, and shifted from one Term to the other, ad libitum. For example, " some abc are clef" may be re-arranged as " some bf are aede" each being equivalent to " some Things are abcdef". Again " No wise old men are rash and reckless gamblers " may be re-arranged as " No rash old gamblers are wise and reckless," each being equivalent to " No men are wise old rash reckless gamblers." & § 2. Syllogisms. Now suppose we divide our Universe of Things in three ways, with regard to three different Attributes. Out of these three Attributes, we may make up three different couples (for instance, if they were a, b, c, we might make up the three couples ab, ac, be). Also suppose we have two Propositions given us, containing two of these three couples, and that from them we can prove a third Proposition containing the third couple. (For example, if we divide our Universe for m, x, and y ; and if we have the two Propositions given us, " no m are x' " and " all m' are y ", con- taining the two couples mx and my, it might be possible to prove from them a third Proposition, containing x and y.) In such a case we call the given Propositions 'the Premisses \ the third one ' the Conclusion ' and the whole set ' a Syllogism \ Evidently, one of the Attributes must occur in both Premisses ; or else one must occur in one Premiss, and its contradictory in the other. Ch. I. § 2.] NEW LAMPS FOR OLD. 21 In the first case (when, for example, the Premisses are " some m are x " and " no m are y' ") the Term, and all x' are y. i. e. All active boys are fat, and all thin ones are lazy. 13. No x exist, and no y' exist, i. e. No cats have green eyes, and none have bad tempers. 14. Some x are y', and some x' are y. Or, some y are #', and some y' are a?, i. e. Some green-eyed cats are bad-tempered, and some, that have not green eyes, are good-tempered. Or, some good-tempered cats have not green eyes, and some bad-tempered ones have green eyes. 15. Some x are y, and no x f are y'. Or, some y are x, and no y' are x'. i. e. Some green-eyed cats are good- tempered, and none, that are not green-eyed, are bad-tempered. Or, some good-tempered cats have green eyes, and none, that are bad-tempered, have not green eyes. 16. All x are y\ and all x' are y. Or, all y are x\ and all y' are x. i. e. All green-eyed cats are bad-tempered, and all, that have not green eyes, are good-tem- pered. Or, all good-tempered ones have eyes that are not green, and all bad-tempered ones have green eyes. [See p. 47 Ch. III. § 6.] CROOKED ANSWERS. 67 § 6. Larger Diagram. Propositions represented. 3. 1 1 1 1 5. [See p. 48] -1- 1 1 1 F 2 68 CROOKED ANSWERS. [Ch. III. 1 9. No x are m. i. e. 10. Some m' are v. i. e. -1- 11. All y r are m' . i. e. -1- [See pp. 48, 9] § 6.] PROPOSITIONS REPRESENTED. 69 12. All m are x\ i. e. 13. No x are m: ) . An r 1 - 6 - All y are m. ) 14. All m' are v; ) . JN o x are m . J 15. All x are m ; ) . No m are y' . l. e. [See p. 49] 70 CROOKED ANSWERS. [Ch. III. 16. All m f are y f ; No x are ra'. 1. e. 17. All a? are m\ All ??i are y, ;},. [See remarks on No. 7, p. 60.] 18. No #' are m ; ) . No m' are y. i. e. 19. All m are a?; ) . All m are ^/. i. e. 1 1 1 [See pp. 49, 50] § 6.] PROPOSITIONS REPRESENTED. 71 20. We had better take "persons" as Universe. We may choose "myself" as 'Middle Term', in which case the Premisses will take the form I am a-person-who-sent-him-to-bring-a-kitten ; | I am a-person-to-whom-he-brought-a-kettle-by-mistake. / Or we may choose "he" as 'Middle Term', in which case the Premisses will take the form He is a-person-whom-I-sent-to-bring-me-a-kitten ; He is a-person-who-brought-me-a-kettle-by-mistake. The latter form seems best, as the interest of the anecdote clearly depends on his stupidity not on what happened to me. Let us then make w. = " he " ; x = " persons whom I sent, &c." ; and y = " persons who brought, &c." All m are x ; ,} Hence, ~7Z ' \ and the required Diagram is All m are y. ' 1 1 [See p. 50] 72 CROOKED ANSWERS. [Ch. III. § 7. Both Diagrams employed. 1. i. e. All y are x'. 1 2. i. e. Some x are y' ; or, Some y' are x. 3. 1 i. e. Some 3/ are *' ; or, Some x are y. 4. o. 6. 1 1 i. e. No x' are y' ; or, No 3/' are a?'. i. e. All y are < .*. Some v are #. JN o y are m. J i. e. Some brave persons get their deserts. [See p. 52] §7.] BOTH DIAGRAMS EMPLOYED. 75 15. Let " persons " be Universe ; m — ■ " patient " ; x = " children n ; y = " that can sit still ". No x are m ; ) ^ T f >\ :. No x No m are y. ) i. e. No children can sit still. are y. 16. i ° 1 o 1 Let " things " be Universe ; m = u fat '" ; x = " pigs " ; y = " skeletons M . All x are m ; , .*. All x are y . No y are m, i. e. All pigs are not-skeletons. [See pp. 52, 3] 76 CROOKED ANSWERS. [Ch. III. 17. 1 1 Let " creatures " be Universe ; m = " monkeys " ; x = " soldiers " ; y = " mischievous ". No m are x ; All m are #. i. e. Some mischievous creatures are not soldiers. ;}■••■ Some y are x'. 18. - Let " persons " be Universe ; m = " just " ; x = " my cousins" ; y = " judges". No a? are ??i ; ) _>_ __ V ,\ No £ are £/. No 3/ are m . J i. e. None of my cousins are judges. [See p. 53] §7.] BOTH DIAGRAMS EMPLOYED. 77 19. Let " periods " be Universe ; m = " days " ; x = " rainy " ; y = " tiresome ". Some 7/i are a? : 1 ^ } .'. borne 05 are y. All #m are 7y. J i. e. Some rainy periods are tiresome. N.B. These are not legitimate Premisses, since the Conclusion is really part of the second Premiss, so that the first Premiss is superfluous. This may be shown, in letters, thus : — " All xm are y " contains " Some xm are y ", which contains " Some x are y". Or, in words, "All rainy days are tiresome " contains " Some rainy days are tiresome ", which contains " Some rainy periods are tiresome " Moreover, the first Premiss, besides being superfluous, is actually contained in the second ; since it is equivalent to " Some rainy days exist ", which, as we know, is implied in the Proposition " All rainy days are tiresome ". Altogether, a most unsatisfactory Pair of Premisses ! [See p. 53] CROOKED ANSWERS. [Ch. III. 20. j o 1 1 ■ Let "things'' be Universe ; m = " medicine " ; x = " nasty " ; y = " senna ". All m are x;) . ,, t .*. All y are x. All y are m. ) i. e. Senna is nasty. LSee remarks on No. 7, p. 60.] 21. 1 1 1 Let " persons " be Universe ; m = " Jews " ; x— u rich " ; y = " Patagonians ". Some m are x ; All y are m' . ;. Some x are y'. i. e. Some rich persons are not Patagonians. [See p. 53] 5 7.1 BOTH DIAGRAMS EMPLOYED. 7 ( J i Let " creatures " be Universe ; m = "teetotalers " ; x = " that like sugar " ; y = " nightingales ". All m are x ; \ XT , \ :. No y are x'. -So y are m .) i. e. No nightingales dislike sugar. 23. 1 [ , Let " food v be Universe ; m = " wholesome " ; a? = " muffins " ; y = " buns '\ No a? are m ; All 2/ are m , There is 'no information' for the smaller Diagram ; so no Conclusion can be drawn. [See p. 53] 80 CROOKED ANSWERS. [C'H. III. 1 1 24. Let " creatures " be Universe ; m = " that run well " ; x = " fat " ; y = " greyhounds ". No x are m ; Some y are m. i. e. Some greyhounds are not fat. .*. Some y are x' . 25. - -1- Let " persons " be Universe ; m = " soldiers " ; a? = " that march " ; y = " youths ". All m are a? ; | Some y are m'. i There is ' no information ' for the smaller Diagram ; so no Conclusion can be drawn. [See p. 53] 7-J BOTH DIAGRAMS EMPLOYED. 81 26. 1 1 1 1 Let " food " be Universe ; m = " sweet " ; x = " sugar " ; y = " salt ". All x are m ; ) . ( All a? are £/'. All y are m'. J I All y are a?'. ( Sugar is not salt. i.e. I Salt is not sugar. 1 1 Let " Things " be Universe ; m = " eggs " ; x = " hard-boiled " ; y = " crackable ". Some m are a? ; ) ^ .'. borne a? are y. No m are gf. i. e. Some hard-boiled things can be cracked. [See p. 53] 82 CROOKED ANSWERS. [Ch. III. 28. Let " persons " be Universe ; m = " Jews " ; x = " that are in the house " ; y = " that are in the garden ". No m are x; ) _ T _ T , V .'. JNo a? are y. JN o m' are y. J i. e. No persons, that are in the house, are also in the garden. 29. — 1 1 Let " Things " be Universe ; m = " noisy " ; x = u battles " ; y = " that may escape notice ". All x are m:\ ~ ... . > .*. borne x are y. All m are y. J i. e. Some things, that are not battles, may escape notice. [See pp. 53, 54] §7.] BOTH DIAGRAMS EMPLOYED. 83 30. 1 Let " persons " be Universe ; rrt = " Jews " ; x = " mad " ; y = u Rabbis " No m are x ; All 2/ are m. i. e. All Rabbis are sane. .\ All y are x. 31. 1 1 Let " Things ,J be Universe ; m = " fish " ; x = " that can swim " ; y = " skates ". No m are x' : Some 2/ are m. i. e. Some skates can swim. [See p. 54] G 2 ? i .*. Some y are #. 84 CROOKED ANSWERS. [Ch. III. § 7. 32. 1 1 Let " people " be Universe ; m = " passionate " ; x =■ " reasonable " ; y = " orators ". All m are a;' ; Some y are i. e. Some orators are unreasonable. I . * Some y are x . 3 m. f J [See remarks on No. 7, p. 60. ] [See p. 54] CHAPTER IV. HIT OR MISS. •'Thou canst not hit it, hit it, hit it, Thou canst not hit it, my good man. " 1. Pain is wearisome ; ) No pain is eagerly wished for. J 2. No bald person needs a hair-brush ; j No lizards have hair. J 3. All thoughtless people do mischief ; | No thoughtful person forgets a promise, i 4. I do not like John ; ) Some of my friends like John, i 5. No potatoes are pine-apples ; j All pine-apples are nice. / 6. No pins are ambitious ; \ No needles are pins. / 7. All my friends have colds ; No one can sing who has a cold. J 8. All these dishes are well-cooked ; Some dishes are unwholesome if not well-cooked. $6 HIT OH MISS. [Oh. IV. 9. No medicine is nice ; Senna is a medicine. 10. Some oysters are silent ; No silent creatures are amusing. 11. All wise men walk on their feet ; | All unwise men walk on their hands. J 12. " Mind your own business ; ) This quarrel is no business of yours." i 13. No bridges are made of sugar; Some bridges are picturesque. 14. No riddles interest me that can be solved ; \ All these riddles are insoluble. j 15. John is industrious ; \ All industrious people are happy, i 16. No frogs write books ; Some people use ink in writing books. 17. No pokers are soft ; All pillows are soft. 18. No antelope is ungraceful ; | Graceful animals delight the eye. / 19. Some uncles are ungenerous; | All merchants are generous. / 20. No unhappy people chuckle; ) No happy people groan. J 21. Audible music causes vibration in the air; | Inaudible music is not worth paying for. i i) Ch. IV.] HIT OR MISS. 87 22. He gave me five pounds ; \ I was delighted. / 23. No old Jews are fat millers ; ) All my friends are old millers, i 24. Flour is good for food ; } Oatmeal is a kind of flour. J 25. Some dreams are terrible ; No lambs are terrible. 26. No rich man begs in the street ; All who are not rich should keep accounts Some dishonest people are found out. J .} 27. No thieves are honest ; Some dishonest people 28. All wasps are unfriendly ; All puppies are friendly. 29. All improbable stories are doubted ; ) None of these stories are probable. J 30. " He told me you had gone away." ) " He never says one word of truth." J 31. His songs never last an hour; } A song, that lasts an hour, is tedious. J 32. No bride-cakes are wholesome ; Unwholesome food should be avoided 33. No old misers are cheerful ; Some old misers are thin. .} 34. All ducks waddle ; Nothing that waddles is graceful. } SS HIT OR MISS. [On. IY^. 35. No Professors are ignorant ; i Some ignorant people are conceited. ) 36. Toothache is never pleasant ; j Warmth is never unpleasant, f 37. Bores are terrible ; ) You are a bore. i 38. Some mountains are insurmountable ; All stiles can be surmounted. 39. No Frenchmen like plumpudding ; ) All Englishmen like plumpudding. i 40. No idlers win fame ; Some painters are not idle. '41. No lobsters are unreasonable ; | No reasonable creatures expect impossibilities, i 42. No kind deed is unlawful; | What is lawful may be done without fear. J 43. No fossils can be crossed in love ; An oyster may be crossed in love. 44. " This is beyond endurance ! " \ " Well, nothing beyond endurance > has ever happened to me" ' 45. All uneducated men are shallow : ) All these students are educated. J 46. All my cousins are unjust ; No judges are unjust. Ch. it.] hit or miss. 89 47. No country, that has been explored, x is infested by dragons ; I Unexplored countries are fascinating. ) 48. No misers are generous ; Some old men are not generous. 49. A prudent man shuns hyaenas ; | No banker is imprudent. J 50. Some poetry is original ; No original work is producible at will. 51. No misers are unselfish ; None but misers save egg-shells. 52. All pale people are phlegmatic ; ) No one, who is not pale, looks poetical, i 53. All spiders spin webs ; ) Some creatures, that do not spin webs, are savage. ) 54. None of my cousins are just ; | All judges are just. J 55. John is industrious ; No industrious people are unhappy. 56. Umbrellas are useful on a journey ; | What is useless on a journey should be left behind. J 57. Some pillows are soft ; | No pokers are soft. J 58. I am old and lame ; \ No old merchant is a lame gambler. / 90 HIT OR MISS. [Oh. IV. 59. No eventful journey is ever forgotten ; \ Uneventful journeys are not worth > writing a book about. ^ 60. Sugar is sweet ; > Some sweet things are liked by children. J 61. Richard is out of temper ; ) No one but Richard can ride that horse. J 62. All jokes are meant to amuse ; j No Act of Parliament is a joke. ) 63. "I saw it in a newspaper." )er. ) " All newspapers tell lies." J ; . . 1 Unpleasant experiences are not anxiously desired. J } 64. No nightmare is pleasant ; Unpleasant experiences are 65. Prudent travellers carry plenty of small change Imprudent travellers lose their luggage. 66. All wasps are unfriendly ; \ No puppies are unfriendly, i 67. He called here yesterday ; ) He is no friend of mine. J 68. No quadrupeds can whistle ; | Some cats are quadrupeds, i 69. No cooked meat is sold by butchers ; \ No uncooked meat is served at dinner, i 70. Gold is heavy ; Nothing but gold will silence him. 71. Some pigs are wild ; There are no pigs that are not fat. Ch. IV.] HIT OR MISS. 9 L 72. No emperors are dentists ; | All dentists are dreaded by children. 1 73. All, who are not old, like walking ; Neither you nor I are old. 74. All blades are sharp ; | Some grasses are blades, i 75. No dictatorial person is popular ; i She is dictatorial. f 76. Some sweet things are unwholesome ; No muffins are sweet. 77. No military men write poetry ; i No generals are civilians. 1 78. Bores are dreaded ; | A bore is never begged to prolong his visit, f 79. All owls are satisfactory ; \ Some excuses are unsatisfactory. J 80. All my cousins are unjust ; | All judges are just. i 81. Some buns are rich ; | All buns are nice. J 82. No medicine is nice ; \ No pills are unmedicinal. j 83. Some lessons are difficult ; j What is difficult needs attention, i 84. No unexpected pleasure annoys me ; | Your visit is an unexpected pleasure. J 92 HIT OB MISS. [Ch. IV. 85. Caterpillars are not eloquent ; | Jones is eloquent. J 86. Some bald people wear wigs ; | All your children have hair. J 87. All wasps are unfriendly ; i Unfriendly creatures are always unwelcome. J 88. No bankrupts are rich ; Some merchants are not bankrupts. 89. Weasels sometimes sleep ; } All animals sometimes sleep. J 90. Ill-managed concerns are unprofitable ; | Railways are never ill-managed. J 91. Everybody has seen a pig; Nobody admires a pig. Extract a Pair of Premisses out of each of the following : and deduce the Conclusion, if there is one : — 92. " The Lion, as any one can tell you who has been chased by them as often as / have, is a very savage animal : and there are certain individuals among them, though I will not guarantee it as a general law, who do not drink coffee." 93. " It was most absurd of you to offer it ! You might have known, if you had had any sense, that no old sailors ever like gruel ! " Cii. IV.] HIT OR MISS. 93 " But I thought, as he was an uncle of yours " " An uncle of mine, indeed ! Stuff ! " " You may call it stuff, if you like. All I know is, my uncles are all old men: and they like gruel like anything!" " Well, then your uncles are " 94. " Do come away ! I can't stand this squeezing any more. No crowded shops are comfortable, you know very well" " Well, who expects to be comfortable, out shopping ? " " Why, I do, of course ! And I'm sure there are some shops, further down the street, that are not crowded. So " 95. " They say no doctors are metaphysical organists : and that lets me into a little fact about you, you know." " Why, how do you make that out ? You never heard me play the organ." " No, doctor, but I've heard you talk about Browning's poetry : and that showed me that you're metaphysical, at any rate. So " Extract a Syllogism out of each of the following : and test its correctness : — 96. " Don't talk to me ! I've known more rich merch- ants than you have : and I can tell you not one of them was ever an old miser since the world began ! " " And what has that got to do with old Mr. Brown ? " 94 BIT OR MISS. [Ch. IV. " Why, isn't he very rich ? " " Yes, of course he is. And what then ? " " Why, don't you see that it's absurd to call him a miserly merchant? Either he's not a merchant, or he's not a miser ! " 97. " It is so kind of you to enquire ! I'm really feeling a great deal better to-day." " And is it Nature, or Art, that is to have the credit of this happy change ? " " Art, I think. The Doctor has given me some of that patent medicine of his." "Well, I'll never call him a humbug again. There's somebody, at any rate, that feels better after taking his medicine ! " 98. " No, I don't like you one bit. And I'll go and play with my doll. Dolls are never unkind." " So you like a doll better than a cousin ? Oh you little silly ! " " Of course I do ! Cousins are never kind at least no cousins Tve ever seen." " Well, and what does that prove, I'd like to know ! If you mean that cousins aren't dolls, who ever said they were ( 99. " What are you talking about geraniums for ? You cant tell one flower from another, at this distance ! I grant you they're all red flowers : it doesn't need a telescope to know that." Ch. IV.] HIT OR MISS. 95 " Well, some geraniums are red, aren't they ? " " I don't deny it. And what then ? I suppose you'll be telling me some of those flowers are geraniums ! " " Of course that's what I should tell you, if you'd the sense to follow an argument ! But what's the good of proving anything to ycni, I should like to know ? " 100. "Boys, you've passed a fairly good examination, all things considered. Now let me give you a word of advice before I go. Eemember that all, who are really anxious to learn, work hard!' " I thank you, Sir, in the name of my scholars ! And proud am I to think there are some of them, at least, that are really anxious to learn." " Very glad to hear it : and how do you make it out to be so ? " " Why, Sir, /know how hard they work some of them, that is. Who should know better ? " Extract from the following speech a series of Syllogisms, or arguments having the form of Syllogisms : and test their correctness. It is supposed to be spoken by a fond mother, in answer to a friend's cautious suggestion that she is perhaps a little overdoing it, in the way of lessons, with her children. 101. "Well, they've got their own way to make in the world. We can't leave them a fortune apiece ! 96 HIT OR MISS. [Ch. IV. And money's not to be had, as you know, without money's worth : they must work if they want to live. And how are they to work, if they don't know any- thing ? Take my word for it, there's no place for ignorance in these times ! And all authorities agree that the time to learn is when you're young. One's got no memory afterwards, worth speaking of. A child will learn more in an hour than a grown man in five. So those, that have to learn, must learn when they're young, if ever they're to learn at all. Of course that doesn't do unless children are healthy : I quite allow that. Well, the doctor tells me no children are healthy unless they've got a good colour in their cheeks. And only just look at my darlings ! Why, their cheeks bloom like peonies ! Well, now, they tell me that, to keep children in health, you should never give them more than six hours altogether at lessons in the day, and at least two half-holidays in the week. And that's exactly our plan, I can assure you ! We never go beyond six hours, and every Wednesday and Saturday, as ever is, not one syllable of lessons do they do after their one o'clock dinner ! So how you can imagine I'm running any risk in the education of my precious pets is more than / can understand, I promise you ! " THE END. [TURX OVER WORKS BY LEWIS CARROLL. PUBLISHED BY MACMILLAN AND CO., LONDON ALICE'S ADVENTURES IN WONDERLAND. With Forty-two Illustrations by Tenniel. (First published in 1865.) Crown 8vo, cloth, gilt edges, price 6s. 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A selection of twenty of the pictures in " Alice's Adventures in Wonderland," enlarged, and coloured under the Artist's superintendence, with expla- nations. [In preparation. N.B. In selling the above-mentioned books to the Trade, Messrs. Macmillan and Co. will abate 2d. in the shilling (no odd copies), and allow 5 per cent, discount for payment within six months, and 10 per cent, for cash. In selling them to the Public (for cash only) they will allow 10 per cent, discount. Mr. Lewis Carroll, having been requested to allow " Ax Easter Greeting " (a leaflet, addressed to children, and frequently given with his books) to be sold separately, has arranged with Messrs. Harrison, of 59, Pall Mall, who will supply a single copy for Id, or 12 for 9c?., or 100 for 55. •:. THE GAME LOGIC BY LEWIS CARROLL PRICE THREE SHILLINGS HonBon MACMILLAIST AND CO. AND NEW YORK 1886 \All Rights reserved I THE GAME LOGIC BY LEWIS CARROLL PRICE THREE SHILLINGS lLonUon MACMILLAN AND CO. AND NEW YORK 1886 [All Rights resetted) I< y X m i* y » x' * £ to to s e O o a a> S £ » t - g £ co C 53 h CO _ o CO £ h4 C3 a S