OBSERVATION AND DESCRIPTION. 211 



different planets, by the proposition that the squares 

 of the times are proportional to the cubes of the dis- 

 tances, what he did was simply to ascertain the pro- 

 perty in which the periodic times of all the different 

 planets agreed. 



Since, therefore, all that is true and to the purpose 

 in Mr. Whewell's doctrine of Conceptions might be 

 fully expressed by the more familiar term Hypothesis ; 

 and since his Colligation of Facts by means of appro- 

 priate Conceptions, is but the ordinary process of find- 

 ing by a comparison of phenomena, in what consists 

 their agreement or resemblance ; I would willingly 

 have confined myself to those better understood 

 expressions, and persevered to the end in the same 

 abstinence which I have hitherto observed from all 

 ideological discussions ; considering the mechanism of 

 our thoughts to be a topic distinct from and irrelevant 

 to the principles and rules by which the trustworthi- 

 ness of the results of thinking is to be estimated. 

 Since, however, a work of such high pretensions, and, 

 it must also be said, of so much real merit, has rested 

 the whole theory of Induction upon such ideological 

 considerations, it seems necessary for others who 

 follow, to claim for themselves and their doctrines 

 whatever position may properly belong to them on the 

 same metaphysical ground. And this is the object of 

 the succeeding chapter. 



P 2 



