250 OPERATIONS SUBSIDIARY TO INDUCTION. 



transition will become a more comprehensive generaliza- 

 tion of the term in question." 



I solicit particular attention to the law of mind 

 expressed in the last sentence, and which is the source 

 of the perplexity so often experienced in detecting 

 these transitions of meaning. Ignorance of that law 

 is the shoal upon which some of the greatest intellects 

 which have adorned the human race have been 

 wrecked. The inquiries of Plato into the definitions 

 of some of the most general terms of moral specula- 

 tion, are characterised by Bacon as a far nearer 

 approach to a true inductive method than is elsewhere 

 to be found among the ancients, and are, indeed, 

 almost perfect examples of the preparatory process of 

 comparison and abstraction ; but, from being unaware 

 of the law just mentioned, he wasted the powers of 

 this great logical instrument upon inquiries in which 

 it could realise no result, since the phenomena whose 

 common properties he so elaborately endeavoured to 

 detect, had not really any common properties. Bacon 

 himself fell into the same error in his speculations on 

 the nature of Heat, in which it is impossible not to 

 think, with Mr. Wheweli, that he confounded under 

 the name hot, classes of phenomena which had no 

 property in common*. Dugald Stewart certainly 

 overstates the matter when he speaks of " a prejudice 

 which has descended to modern times from the scho- 

 lastic ages, that when a word admits of a variety of 

 significations, these different significations must all be 

 species of the same genus, and must consequently 

 include some essential idea common to every indivi- 

 dual to which the generic term can be applied f:" for 



* History of the Inductive Sciences, i., 48. 

 t Philosophical Essay s, p. 214. 



