II. Criticism of Aristotle's Account of Induction. By W. Whewell, D.D. 



QRead February 11, 1850.] 



The Cambridge Philosophical Society has willingly admitted among its proceedings not 

 only contributions to science, but also to the philosophy of science ; and it is to be presumed 

 that this willingness will not be less if the speculations concerning the philosophy of science 

 which are offered to the Society involve a reference to ancient authors. Induction, the process 

 by which general truths are collected from particular examples, is one main point in such 

 philosophy : and the comparison of the views of Induction entertained by ancient and modern 

 writers has already attracted much notice. I do not intend now to go into this subject at any 

 length ; but there is a cardinal passage on the subject in Aristotle's Analytics, (Analyt. Prior. 

 n. 25) which I wish to explain and discuss. I will first translate it, making such emendations 

 as are requisite to render it intelligible and consistent, of which I shall afterwards give an 

 account. 



I will number the sentences of this chapter of Aristotle in order that I may afterwards 

 be able to refer to them readily. 



§ 1 " We must now proceed to observe that we have to examine not only syllogisms 

 according to the aforesaid figures, — syllogisms logical and demonstrative, — but also rhetorical 

 syllogisms, — and, speaking generally, any kind of proof by which belief is influenced, following 

 any method. 



§ 2 " All belief arises either from Syllogism or from Induction : [we must now 

 therefore treat of Induction.] 



X 3 " Induction, and the Inductive Syllogism, is when by means of one extreme term 

 we infer the other extreme term to be true of the middle term. 



$ 4 " Thus if A, C, be the extremes, and B the mean, we have to shew, by means of C, 

 that A is true of B. 



§5 " Thus let A be long-lived ; B, that which has no gall-bladder ; and C, particular 

 long-lived animals, as elephant, horse, mule. 



fi 6 " Then every C is A, for all the animals above named are long-lived. 



§7 " Also every C is B, for all those animals are destitute of gall-bladder. 



§8 "If then B and C are convertible, and the mean (B) does not extend further than 

 extreme (C), it necessarily follows that every B is A. 



§ 9 " For it was shewn before, that, if any two things be true of the same, and if 

 either of them be convertible with the extreme, the other of the things predicated is true of the 

 convertible (extreme). 



^ 10 " But we must conceive that C consists of a collection of all the particular cases ; 

 for Induction is applied to all the cases. 



