XI PHENOMENA OF ORGANIC NATURE 365 



ciples of inductive and deductive philosophy dur 

 ing the same period. 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 reason 

 ing, 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 serve to ex 

 emplify 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 analyse 

 and trace out into its logical elements what has 

 been done by the mind, you will be greatly sur 

 prised. In the first place, you have performed 

 the operation of induction. You found that, in 

 two experiences, hardness and greenness in apples 

 went 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 



