366 THE CAtJSES OF THE xi 



to make an induction from ; you generalise 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 

 is hard and green, therefore this apple is sour." 

 That train of reasoning is what logicians call a 

 syllogism, and has all its various parts and terms, 

 its major premiss, its minor premiss, and its 

 conclusion. And, by the help of further reason- 

 ing, which, if drawn out, would have to be exhibited 

 in two or three other syllogisms, you arrive at your 

 final determination, " I will not have that apple." 

 So that, you see, you have, in the first place, 

 established a law by induction, and upon that you 

 have founded a deduction, and reasoned out the 

 special conclusion of the particular case. Well 

 now, suppose, having got your law, that at some 

 time afterwards, you are discussing the qualities 

 of apples with a friend : you will say to him, " It is 

 a very curious thing, but I find that all hard and 

 green apples are sour ! " Your friend says to you, 

 " But how do you know that ? " You at once 

 reply, " Oh, because I have tried them over and 

 over again, and have always found them to be so." 

 Well, if we were talking science instead of common 



