Dr. WHEWELL'S CRITICISM OF ARISTOTLE'S ACCOUNT OF INDUCTION. 67 



Acholous animals are long-lived : 



All elephants are acholous animals : 



Therefore all elephants are long-lived. 

 But Induction proves by means of a third thing (namely, particular cases) that the extreme is 

 true of the mean ; thus (acholous, still being the middle term) 



Elephants are long-lived : 



Elephants are acholous animals : 



Therefore acholous animals are long-lived. 

 It may be objected, such reasoning as this is quite inconclusive: and the answer is, that this 

 is precisely what we, and as I believe, Aristotle, are here pointing out. Induction is inconclusive 

 as reasoning. It is not reasoning: it is another way of getting at truth. As we have seen, 

 no reasoning can prove such an inductive truth as this, that all planets describe ellipses. It 

 is known from observation, but it is not demonstrated. Nevertheless, no one doubts its uni- 

 versal truth, (except, as aforesaid, when disturbing causes intervene). And thence, Induction is, 

 as Aristotle says, opposed to syllogistic reasoning, and yet is a means of discovering truth : not 

 only so, but a means of discovering primary truths, immediately derived from observation. 



I have elsewhere taught that all Induction involves a Conception of the mind applied 

 to facts. It may be asked whether this applies in such a case as that given by Aristotle. 

 And I reply, that Aristotle's instance is a very instructive example of what I mean. The 

 Conception which is applied to the facts in order to make the induction possible is the 

 want of the gall-bladder ; — and Aristotle supplies us with a special term for this con- 

 ception ; acholous*. But, it may be said, that the animals observed, the elephant, horse, 

 mule, &c, are acholous, is a mere Fact of observation, not a Conception. I reply that it is a 

 Selected Fact, a fact selected and compared in several cases, which is what we mean by a 

 Conception. That there is needed for such selection and comparison a certain activity of the 

 mind, is evident ; but this also may become more clear by dwelling a little further on the 

 subject. Suppose that Aristotle, having a desire to know what class of animals are long-lived, 

 had dissected for that purpose many animals ; elephants, horses, cows, sheep, goats, deer and 

 the like. How many resemblances, how many differences, must he have observed in their 

 anatomy ! He was very likely long in fixing upon any one resemblance which was common 

 to all the long-lived. Probably he tried several other characters, before he tried the presence 

 and absence of the gall-bladder : — perhaps, trying such characters, he found them succeed for 

 a few cases, and then fail in others, so that he had to reject them as useless for his purpose. 

 All the while, the absence of the gall-bladder in the long-lived animals was a fact : but it 

 was of no use to him, because he had not selected it and drawn it forth from the mass of other 

 facts. He was looking for a mean term to connect his first extreme, long-lived, with his 

 second, the special cases. He sought this middle term in the entrails of the many animals 

 which he used as extremes : it was there, but he could not find it. The fact existed, but 

 it was of no use for the purpose of Induction, because it did not become a special Conception 

 in his mind. He considered the animals in various points of view, it may be, as ruminant, 



* This term occurs in other parts of Aristotle. See the additional Note. 



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