INDUCTIONS IMPROPERLY SO CALLED. 357 



concluding that the position of the planet during the 

 time which intervened between two observations, must 

 have coincided with the intermediate points of the 

 curve. But this really inductive operation requires 

 to be carefully distinguished from the mere act of 

 bringing the facts actually observed under a general 

 description. So distinct are these two operations, 

 that the one might have been performed without the 

 other. Men might and did make correct inductions 

 concerning the heavenly motions, before they had 

 obtained correct general descriptions of them. It 

 was known that the planets always moved in the 

 same paths, long before it had been ascertained that 

 those paths were ellipses. Men early remarked 

 that the same set of apparent positions returned peri- 

 odically. When they obtained a new description of 

 the phenomenon, they did not necessarily make any 

 further induction, nor (which is the true test of a 

 new general truth) add anything to the power of 

 prediction which they already possessed. 



4. The descriptive operation which enables a 

 number of details to be summed up in a single propo- 

 sition, Mr. Whewell, by an aptly-chosen expression, 

 has termed the Colligation of Facts *. In most of his 

 observations concerning that mental process I fully 

 agree, and would gladly transfer all that portion of 

 his book into my own pages. I only think him mis- 

 taken in setting up this kind of operation, which 

 according to the old and received meaning of the term., 

 is not induction at all, as the type of induction gene- 

 rally ; and laying down, throughout his work,, as prin- 

 ciples of induction, the principles of mere colligation. 



Philosophy of the Inductive Sciences, ii., 213, 214. 



