46 MENTAL EVOLUTION IN MAN. 



laborious inquiries in several directions, I will endeavour to 

 keep the various issues distinct by fully working out each 

 branch of the subject before entering upon the next. 



First of all I will show, by means of illustrations, the 

 highest levels of ideation that are attained within the domain 

 of rccepts ; and, in order to do this, I will adduce my evidence 

 from animals alone, seeing that here there can be no suspicion 

 — as there might be in the case of infants — that the logic of 

 recepts is assisted by any nascent growth of concepts. But, 

 before proceeding to state this evidence, it seems desirable to 

 say a few words on what I mean by the term just used, namely, 

 Logic of Recepts. 



As argued in my previous work, all mental processes of 

 an adaptive kind are, in their last resort, processes of classifi- 

 cation : they consist in discriminating between differences and 

 resemblances. An act of simple perception is an act of 

 noticing resemblances and differences between the objects of 

 such perception ; and, similarly, an act of conception is the 

 taking together — or the intentional /z^^*////^ together — of ideas 

 which are recognized as analogous. Hence abstraction has to 

 do with the abstracting of analogous qualities ; reason is 

 ratiocination, or the comparison of ratios ; and thus the highest 

 operations of thought, like the simplest acts of perception, are 

 concerned with the grouping or co-ordination of resemblances, 

 previously distinguished from differences.* Consequently, the 

 middle ground of ideation, or the territory occupied by recepts, 

 is concerned with this same process on a plane higher than 

 that which is occupied by percepts, though lower than that 

 which is occupied by concepts. In short, the object or use, 

 and therefore the method or logic, of all ideation is the same. 

 It is, indeed, customary to restrict the latter term to the 

 higher plane of ideation, or to that which has to do with 

 concepts. But, as Comte has shown, there is no reason why, 

 for purposes of special exposition, this term should not be 

 extended so as to embrace all operations of the mind, in so 



* As stated in a previous foot-note, this truth is well exhibited by M. Binet, 

 loc. cit. 



