ORGANON. 



OBQAHON. 



winn-thing of something, and on the other side denying nomething from 

 (*4) something. (' Anal.vt. Port., 



In affirmation and negation alway*, whether it U a thing that exists 

 or dot* not exist, the one will tie f.ilio and the other true : for of the 

 two that Socrates in sick ami that Socrates U not nick, when Socrates 

 rxiU, it U manifest that one of them U true and the other falie, and if 

 he doe* not exist in the name manner : for that he U lick, when he 

 doe* not exist, U false, and that he U not nick is true. 



Accordingly, to these things alone, which are opposed aa affirmation 

 and negation, it will be peculiar for one of them always to be true or 

 false. ('Categ./c. in.) 



1 1 l.t Things included in the same genus which differ moat from one 

 another, are defined to be contrary (Atbria). (' Categ./ c. 6.) 



1 1..) Therefore I say that affirmation is opposed to negation in the 

 way of contradiction, when the one signifies that a thing is universal 

 and the other signifies that the same is not universal : as for example, 

 every man is white not every man U white; no man is white a 

 certain man is white. And I say that the universal affirmation and 

 negation are opposed as contraries : as for example, every man U white 

 no man is white ; every man is just no man is just. Therefore it 

 is not possible for these to be true at the same time. {' Do Interpret.,' 

 c.7.) 



(IS.) And I Kay that propositions opposed are in common expression 

 (xara A'{I>>) four namely, all and none, all and not all, some and none, 

 some and not some ; but in truth three ; for some is opposed to not 

 some merely in expression. And of these three propositions the 

 universal, all and none, are contrary : for example, all knowledge is 

 excellent, no knowledge is excellent ; but the other propositions are 

 opposed (as contradictory). (' Analyt. Pr.,' ii. 15.) 



(14.) And since every proposition is either of being or of 

 necessarily being or of the possibility of being, and of these some are 

 affirmative and some negative in every mode, and again of the affir- 

 mative and negative propositions some are universal and some particular 

 and some indefinite, of necessity the proposition which is universally 

 negative can be converted (i>riaTp'4>ci) in its terms (tpoi) : for example, 

 if no pleasure is a good thing, neither is any good thing pleasure ; but 

 the affirmative proposition must be converted, not indeed universally 

 but particularly ; thus if all pleasure is good, some good also is 

 pleasure. And of particular propositions the affirmative proposition 

 must be converted particularly, for if some pleasure is good, some good 

 also is pleasure : but as to the negative, it is not of necessity, for, if 

 " man " does not belong to (cannot be predicated of) some animal, it 

 does not follow that " animal " cannot be predicated of " some man," 

 (' Analyt. Pr.,' i. 2.) 



(15.) The things which are sought are equal in number to the things 

 which we know. And we seek four things the That, the Why, If it 

 is. What it is. (rb Sri, rb Stirt, tt tffri, rl iirrtr.) For when we seek 

 whether this or that is, referring it to number, for example, whether 

 the sun is eclipsed or not, we seek the That. And there is proof of 

 this ; for when we have found out That it is eclipsed, we cease inquiring ; 

 and if from the beginning we know That it is eclipsed, we do not 

 inquire whether it is. And when we know that it is, we inquire the 

 Why : for example, when we know that the sun is eclipsed, and that 

 the earth moves, we inquire Why the sun is eclipsed, or Why the earth 

 moves. These things accordingly we inquire after thus; but some 

 things we inquire after in another manner, as for example, Whether 

 there is or is not Centaur or God. I simply mean if there is or is not, 

 but not if he is white or not. And when we know that there is, we 

 inquire What it is, for example, What is God or what is man. (' Analyt. 

 Post.,' ii. 1.) 



(16.) To know That a tiling is and to know Why it is are different ; 

 and the knowledge of the Why refers to the first cause. The chief eat 

 of knowledge is to contemplate the Why. (' Analyt. Post-,' i. 13, 14.) 



(17.) And we think that we know each thing simply when we think 

 that we both know the cause by which the thing is, that it is its cause, 

 and that it cannot be otherwise. ('Analyt. Post.,' i. 2.) 



(18.) All instruction and all rational learning come from knowledge 

 preceding. And this is manifest to them who contemplate all (sciences) ; 

 for both those of the sciences which are mathematical by these means 

 exist, and every one of the other arts. (' Analyt. Post,' L I.) 



(19.) And things are prior and better known in two ways : for it is 

 not the same thing to be prior by nature and prior as regards us, nor 

 yet to be more known by nature and more known by us. And I call 

 those things prior and more known as regards us which are nearer the 

 sense, but I call simply prior and more known those things which are 

 farther from the perception. And the farthest off are the most 

 universal, and the nearest are the particular. ('Analyt. Post.,' i. 2.) 



(20.) We get certainty in all things either by syllogism (ovAAoyur/uis) 

 or by induction (ttaytrft). (' Analyt. Pr./ ii. 23.) 



\\ . learn cither by induction or demonstration (4cfJi|if) ; and 

 demonstration proceed* from the general, but induction from the 

 particular. (' Analyt Post,' i. 18.) 



(21.) And syllogism is speech, in which when some things arc laid 

 down, something eUe different from what are laid down results by 

 virtue of their being laid down ; and by virtue of their being laid 

 down I mean that it result* through them ; and I mean by resulting 

 through them, that there is no need of any external term for the 

 necessity to be. (' Analyt. Pr./ i. 1.) 



And I call Term that into which the proposition U resolved, as 

 the predicate and the thing of which it is predicated (subject). 

 (' Analyt. Pr./ L 1.) 



<-'".) Whatsoever is affirmed of the predicate (TOW Kariryapou^vav), 

 will bo affirmed of the subject (roi irotttipfaw) also. (' CaU'g.,' c. 6.) 



(24.) When three terms are BO related to one another that the last 

 is in the whole of the middle, and the middle is either in or not in the 

 whole of the first, of necessity there is a perfect syllogism of the 

 extremes. And I call middle (iuam) that which is both itself in 

 another and another in it, and which also by position becomes middle : 

 And I call extremes (Sxpo) both that which in in another, and in which 

 another is. For if A can be predicated of all D, and n of all c, neces- 

 sarily A can be predicated of all c. And I call a figure (<rxw0 f 8u h 

 description the first. (' Analyt. Pr./ i. 4.) 



(25.) And when the same thing belongs to all of one thing and to 

 none of another, or to all or none of each, such a figure I call the 

 second, and that which is predicated of both I call the middle term in 

 it And the middle term is placed without the extremes, but the first 

 in posi ti on And a syllogism will be possible both when the terms are 

 universal and when they are not universal. When they are universal, 

 there will be a syllogism, when the middle is in all of one, nnd in none 

 of the other, if the negative be in one of the two terms : but other- 

 wise the syllogism cannot be. 



For let u be predicated of no part of N, but of all x. Since then Uic 

 negative proposition can be converted, N will belong to no part of u : 

 but M by the supposition was predicated of all x. Accordingly N will 

 be no part of x : for this has been shown before. Again, if M .-hull 

 belong to all N, but to no part of x, neither will N belong to any part 

 of x : for if M belongs to no part of x, neither will x belong to any 

 part of M : but M by the supposition belongs to all N. Therefore x 

 will belong to no part of N : for this also has become the first figure. 

 And since the negative proposition U convertible, (4iri<jTp<J>i) neither 

 will N belong to any part of x, so that there will be the same syllogism. 

 An affirmative syllogism is not produced by means of this figure, but 

 they are all negative, both the universal syllogisms and the particular 

 syllogisms. (' Analyt.' i. 5.) 



" (26.) But if one thing belongs to the whole of the same thing and 

 another belongs to no part of it, or both to the whole or to no jwrt, 

 such a figure I call the third ; and I call that the middle in it of which 

 both the predications are made, and I call the extremes the predicates : 

 And the middle is placed without the extremes, and last in \<~ 

 And a syllogism will be possible both when the terms are universal 

 and when not universal with reference to the middle. 



Accordingly if they are universal, when both p and R belong to all 

 8, F will belong to some part of n of necessity : for since the affirma- 

 tive is convertible, s will belong to some part of n, so that since p 

 belongs to all of 8, and 8 to some part of n, of necessity p belongs to 

 some part of n : for the syllogism is produced by means of the first 

 figure. 



To form a syllogism universally by means of this figure is not 

 possible, neither in the negative nor in the affirmative. (' Analyt. 

 Pr./ i. 6.) 



(27.) And it is manifest that every demonstration will be by means 

 of three terms and not more. And since this is clear, it is manifest 

 that it consists of two propositions and not more : for the three terms 

 are two propositions. (' Analyt. Pr./ i. 25.) 



(28.) It is necessary in all the figures that the middle be in both 

 the propositions. If then the middle term both predicate and be the 

 subject of predication, or itself predicates and anything is denied of it, 

 it will be the first figure: but if it both predicates and is denied of 

 something, it will be the middle figure : and if other thin 

 predicated of it, or one thing is denied and another predicated, it will 

 be the last figure. (' Analyt. Pr./ i. 82.) 



(29.) Moreover in all syllogisms one of the terms must be affirmative 

 and it must be universal : for without the universal there will either 

 be no syllogism, or it will not relate to the thing proposed, or the very 

 thing to be proved will be assumed. For let it be proposed to prove 

 that music is an honourable pleasure ; if then any one should assume 

 that pleasure is honourable without adding the " all," it will not be a 

 syllogism : and if he should assume that some pleasure is excellent, 

 if he means other pleasure, it has nothing to do with the subject 

 proposed, and if he means the very pleasure itself, he assumes the M TV 

 thing which is to be proved. ('Analyt. Pr./ i. 24.) 



(30.) The science of what a thing is, it is possible to investigate by 

 means of this figure alone (the first). For in the middle figure the 

 syllogism is not affirmative, and (the question) what science is, requires 

 the affirmative : and in the last figure there is a syllogism, but not a 

 universal syllogism, and the question what a thing is, belongs to the 

 universal. ('Analyt. Post./ i. 14.) 



(31.) All who attempt to syllogise from things less credible than 

 the conclusion, manifestly do not syllogise rightly. (' Top./ viii. 6.) 



(32.) From what is true it is not possible to form a false conclusion, 

 but from what is false it is possible to form a true conclusion ; not 

 however " why " but " that " the thing is. (' Analyt. Pr.,' ii. 2. 

 Accordingly it is manifest that, if the conclusion be false, of necessity 

 those things are false either wholly or partly from which the argumen- 

 tation (\6yos) is derived ; but when the conclusion is true, it is not a 

 matter of necessity for either anything or all to be true, but it is 



