157 



ORGANON. 



ORGANON. 



153 



possible when none of the things in the syllogism are true, for the 

 conclusion to be true notwithstanding, but not as a matter of 

 necessity. And the reason is, that, when two things are so related to 

 one another, that when one is, of necessity the other is, when this 

 other is not, neither will the first be, but when it is, it is not a matter 

 of necessity that the first be. (' Analyt. Pr.,' ii. 4.) 



(S3.) And a Philosophema is a syllogism demonstrative, and an 

 Epicheirema a syllogism dialectic, and a Sophisma a syllogism con- 

 tentious, and an Aporema a dialectic syllogism of contradiction. 

 (' Top.,' viii. 11.) Demonstration then is, when from true and first 

 things the syllogism comes, or from things of such a kind which by 

 means of some first and true things have received the beginning of the 

 knowledge concerning them : and a Dialectic syllogism is that syllogism 

 which is derived from common notions. (' Top.,' i. 1.) 



And speech is called false in one manner, when it appears to be 

 conclusive but is not conclusive, which is called a contentious syllogism 

 (ipurrucis ffv\\oyiff^s). (' Top.,' viii. 12.) 



Contentious speech is the syllogising from notions that appear to be 

 common notions, but are not ; or it is merely apparent syllogising. 

 (' Soph. Elench.,' 2.) 



The equality of opposite arguments (\oyiffpot) would appear to be 

 productive of doubt. (' Top.,' vi. 5.) 



(34.) Induction (ixayarrfi) ia the progress from the particular to the 

 universal : thus if a pilot who is skilled is the best, and if a charioteer 

 who is skilled is so, universally also the person who is skilled in each 

 * thing is the best. And induction is the more persuasive and more 

 clear, and more intelligible to sense, and in vogue among the many ; 

 but the syllogism has more force and is more effective against opponents 

 in argument. (' Top.,' i. 12.) 



(35.) Induction then and the syllogism from induction, is through 

 one extreme to syllogise the other with the middle term ; for example, 

 if B is the middle term of A and c, by means of c to show that A may 

 be predicated of B : for thus we male inductions. But c must be 

 considered as composed of all things individually : for induction is 

 made through all. (' Analyt. Pr.,' ii. 23.) 



(36.) In a manner induction is opposed to syllogism ; for the one 

 (syllogism) by means of the middle term proves the first term to be 

 predicated of the third, but the other (induction), by means of the 

 third term, proves the first to be predicated of the middle term. 

 Naturally then the syllogism through the middle term is prior and 

 more familiar ; but to us the syllogism through induction is the 

 Analyt. Pr.,'ii. 23.) 



(37.) Probable (tiViij) and Sign (enj^eiui') are not the same, but 

 Probable is a proposition conformable to opinion : for what for the 

 moot part men know to be produced in a particular way or not 

 produced, or to be or not to be, this ia probable ; for example, that men 

 hate the envious, or like those who love. And Sign must be con- 

 sidered to be a proposition demonstrative cither necessary or conformable 

 to opinion : for if when anything is, the thing is, or when anything has 

 happened, the thing happens before or after, this is a sign of the thing 

 having happened or being. 



Enthymeina then (irevfai/a.) is a syllogism from probables or signs. 

 (' Analyt. Pr.,' ii. 27.) 



(38.) And an example is, when the first is shown to belong (inrdpxor) 

 to the middle through one like the third. But it must be known that 

 both the middle belongs to the third and the first to the like. For 

 example, let A be bad, and B be to take up war against neighbours ; 

 and c, the Athenians, taking up war against the Thebans ; and D/the 

 Thebans, taking up war against the Phocians. If then we wish to 

 show that to make war on the Thebans is a bad thing, we must assume 

 that to make war on neighbours is bad. And the evidence of this is 

 from the like things, for example, that the war of the Thebans against 

 the Phocians ia bad. Since then to make war on neighbours is bad, 

 and since the war against the Thebans ia against neighbours, it is 

 manifest that to war against the Thebans is bad. Accordingly it is 

 clear that B belongs to c and to o (for both c and D are to take up war 

 against neighbours), and that A belongs to D (for the war of the 

 us against the Phocians wan not good) ; but that A belongs to B 

 will be shown through D. 



And in the same manner also if through more like things, the 

 evidence should exist of the middle belonging to the first. Accordingly 

 it is manifest that the example is neither as a part to the whole, nor as 

 a whole to a part, but as a part to a part, when both arc included in 

 the same notion, and the one is known. And it differs from induction, 

 uch as induction by means of all the particulars shows that the 

 first belongs to the middle, and does not connect the syllogism with 

 the first, but the example both connect* it and docs not derive its 

 evidence from all the particulars. (' Analyt. Pr.,' ii. 24.) 



(39. Both modes of proof, that by syllogisms and that by induction, 

 teach by means of things known before; tha one taking its assumptions 

 the general notions of mankind, and the other showing the uni- 

 versal through the evidence of the particular. And in the same manner 

 nts persuade ; fur tln-y (the arguments) are either by 

 means of example, whirli is induction, or by means of enthymemata, 

 whi. Analyt. Post.,' i. 1.) 



i Refutation (?As7x) is a syllogism of contradiction. ('Analyt. 



i And objection (iyarsura) u a proposition contrary to a propo- 



sition. And it differs from the proposition, in as much as it is possible 

 for the objection to be particular, but the proposition either cannot be 

 so at all, or at least not in the universal syllogisms. ('Analvt. Pr.,' 

 ii. 26.) 



(42.) Since it is the nature of some things through themselves to be 

 known, and of some through other things (for principles (apxal) are 

 known through themselves, but other things subordinate to principles 

 are known through other things), when any one attempts to show 

 through itself a thing not known through itself, then the thing to be 

 proved (T)> e{ apxTJs) is assumed. (' Analyt. Pr.,' ii. 16.) 



And people appear to assume what is to be proved in five ways. 

 Most manifestly and first, if a person should assume that which 

 requires to be proved. And this in itself does not easily escape notice ; 

 but in common names (ffvvun'v/ia.),* and in all those things in which the 

 name and the notion (\6yos) have the same meaning, it is more easy to 

 escape detection. And the second way is when a person assumes the 

 universal when it is necessary to prove the particular ; for example, if a 

 person attempting to show that of contrary things (tVcJvria) there is one 

 science, should universally assume that of opposed thiugs (apri/tci/ueW) 

 there is one science ; for he appears to assume with many other things 

 that which it was requisite to prove by itself. The third way is, if 

 any one, when the thing proposed is to show the universal should 

 assume the particular ; for example, if he had to prove that of all cou- 

 trnry things there is one science, he should assume that there is one 

 science of some particular contrary things ; for such a one also appears 

 to assume separately by itself that which it was requisite to prove 

 together with others. Again, if any one should assume the problem (ri 

 xpo&\-il8iv) by dividing it ; for example, if, when it was required to 

 show that the art of medicine concerned both health and sickness, he 

 should assume each separately. Or if any one should assume one of 

 two things which follow one another of necessity ; for example, that 

 the side (of a square) has no common measure with the diagonal, when 

 it was required to show that the diagonal has no common measure 

 with the side. (' Top.,' viii. 13.) 



(43.) The affirmative (demonstration) is prior to the negative, and 

 more easily known, for through the affirmation the negation is known, 

 and the affirmation is prior, as being also is prior to not being. Further, 

 it is nearer to a first principle ; for without the positive proof there is 

 no negative proof. (' Analyt. Post,' i. 25.) 



(44.) All persons who form a conclusion through that which is 

 impossible, form indeed a false conclusion, but they show what has to 

 be demonstrated by virtue of an hypothesis, when anything impossible 

 results by the assumption of the contradiction (avrlQwrts) (10). 

 ('Analyt. Pr.,' i. 23.) 



The demonstration which leads to an impossibility is thus : If it 

 were required to show that A does not belong (inrdpxf) to B, it must 

 be assumed that it does, and that B belongs to c, so that it follows that 

 A belongs to c. But let this (that A belongs to C) be known and agreed 

 to be impossible. Then it is not possible .for A to belong to B. If 

 then it is granted that B belongs to c, it is impossible for A to belong 

 to B. And since the affirmative (KaTrryopurfi) demonstrative is better 

 than the negative, it is manifest that it is also better than the demon- 

 strative which leads to impossibility. (' Analyt. Post.,' i. 26.) 



(45.) The object of science and science differ from the object of 

 opinion and opinion, inasmuch as science is universal and is of neces- 

 sity, and the necessary can not be otherwise, but opinion is unsettled. 

 (' Analyt. Post.,' i. 33.) 



(46.) Induction is not possible when there is no sensuous perception; 

 for sensuous perception belongs to the particular. Nor yet through 

 sense nor through perception is it possible to attain science. For 

 though sensuous perception refers to a thing as being of a certain 

 quality, and not to any definite thing, nevertheless it is necessary to 

 have some one definite thing as the sensuous object, and the where and 

 the when. But what is universal and in all things it is impossible to 

 have sensuous perception of, for it is neither any particular thing nor 

 now ; for, if it were, it would not be universal ; for we affirm that the 

 always and the everywhere are universal. Wherefore, also, if we were 

 in the moon and saw the earth intercepting (the light of the sun), we 

 should not know the cause of the eclipse ; for we should perceive 

 that it is eclipsed now, but we should not know why at all, for there 

 would be no sensuous perception of the universal. (' Analyt. Post.,' i. 

 18,31.) 



(47.) And I call universal whatever belongs to all both of itself and 

 in itself. It is manifest, then, that whatever is universal of necessity 

 belongs to the things. And the " of itself " and " in itself " are the 

 same ; for example, of itself a point belongs to a line inasmuch as it is 

 a line ; and to a triangle, inasmuch as it is a triangle, there belong two 

 right angles ; for of itself the triangle (as to angles) is equal to two 

 right angles. And the universal then is, when it can be demonstrated 

 of any individual (of the class) and of no class prior to that. (' Analyt. 

 Post,' i. 4.) 



(48.) To what thing anything of itself belongs, that very thing is its 

 own cause (alnov) ; and the universal is first, therefore the universal is 

 the cause. (' Analyt. Post.,' i. 24.) 



(49.) Universally, of all things it is impossible for there to be demon- 

 stration ; for it would proceed indefinitely, so that thus there would be 



Sec ' Catcg.' c. 1, dclinitiou of 



