48 METHOD OF DISCOVERY 



delight on being told that he had been talking prose during 

 ; i(ile of his life. In the same way, I trust, that you 

 will take comfort, and be delighted with yourselves, on 

 the discovery that you have been acting on the principles 

 of inductive and deductive philosophy during the same 

 i. Probably there is not one here who has not in the 

 course of the day had occasion to set in motion a complex 

 train of reasoning, of the very same kind, though differing 

 of course in degree, as that which a scientific man goes 

 through in tracing the causes of natural phenomena. 



A very trivial circumstance will serv.e to exemplify this. 

 Suppose you go into a fruiterer's shop, wanting an apple, 

 you take up one, and, on biting it, you find it is sour ; 

 you look at it, and see that it is hard and green. You take 

 up another one, and that too is hard, green, and sour. 

 The shopman offers you a third ; but, before biting it, you 

 examine it, and find that it is hard and green, and you 

 immediately say that you will not have it, as it must be 

 sour, like those that you have already tried. 



Nothing can be more simple than that, you think ; 

 but if you will take the trouble to analyze and trace out 

 Into its logical elements what has been done by the mind, 

 you will be greatly surprised. In the first place, you have 

 performed the operation of Induction. You found that, 

 in two experiences, hardness and greenness in apples go 

 together with sourness. It was so in the first case, and 

 it was confirmed by the second. True, it is a very small 

 basis, but still it is enough to make an induction from ; you 

 p-n< rali/.f the facts, and you expect to find sourness in apples 

 where you get hardness and greenness. You found upon 

 that a general law, that all hard and green apples are sour ; 

 and that, so far as it goes, is a perfect induction. Well, 

 having got your natural law in this way, when you are 

 offered another apple which you find is hard and green, 

 you say, " All hard and green apples are sour ; this apple 

 ;d and preen, therefore this apple is sour." That 

 of reasoning is what logicians call a syllogism, and 

 i t;s parts and terms, its major premiss, its 

 minor . and its conclusion. And, by the help of 



fnrt In r reasoning, which, if drawn out, would have to be 

 exhibited in two or three other syllogisms, you arrive 

 ;r final <1< termination, " I will not have that apple." 

 So lhat, you SIT, you have, in the first place, established a 

 law by Induction, and upon lhat you have founded a 



