EXAMPLES OF THE FOUR METHODS. 505 



by subtracting from the differences of intellect which 

 we in fact see, all that can be traced by known laws 

 either to the ascertained differences of physical 

 organization, or to the differences which have existed 

 in the outward circumstances in which the subjects 

 of the comparison have hitherto been placed. What 

 these causes might fail to account for, would constitute 

 a residual phenomenon, which and which alone would 

 be evidence of an ulterior original distinction, and the 

 measure of its amount. But the strongest assertors 

 of such supposed differences have hitherto been very 

 negligent of providing themselves with these neces- 

 sary logical conditions of the establishment of their 

 doctrine. 



The spirit of the Method of Residues being, it is 

 hoped, sufficiently intelligible from these examples, 

 and the other three methods having been so aptly 

 exemplified in the inductive processes which produced 

 the Theory of Dew, we may here close our exposition 

 of the four methods, considered as employed in the 

 investigation of the simpler and more elementary 

 order of the combinations of phenomena. 



