214 OPERATIONS SUBSIDIARY TO INDUCTION. 



that Induction could not go on without general 

 conceptions. 



2. But it does not therefore follow that these 

 general conceptions must have existed in the mind 

 previously to the comparison. It is not (as Mr. 

 Whewell seems to suppose,) a law of our intellect, that 

 in comparing things with each other and taking note 

 of their agreement we merely recognise as realized in 

 the outward world something that we already had in 

 our minds. The conception originally found its way 

 to us as the result of such a comparison. It was 

 obtained (in metaphysical phrase,) by abstraction from 

 individual things. These things may be things which 

 we perceived or thought of on former occasions, but 

 they may also be the things which we are perceiving 

 or thinking of on the very occasion. When Kepler 

 compared the observed places of the planet Mars, and 

 found that they agreed in being points of an elliptic 

 circumference, he applied a general conception which 

 was already in his mind, having been derived from his 

 former experience. But this is by no means the uni- 

 versal case. When we compare several objects and 

 find them to agree in being white, or when we compare 

 the various species of ruminating animals and find 

 them agree in being cloven-footed, we have just as 

 much a general conception in our minds as Kepler had 

 in his : we have the conception of " a white thing," 

 or the conception of " a cloven-footed animal." 

 But no one supposes that we necessarily bring these 

 conceptions with us, and superinduce them (to adopt 

 Mr. WhewelPs expression*) upon the facts: because 

 in these simple cases everybody sees that the very act 



* Philosophy of tJie Inductive Sciences, i. 42. 



