82 E. L. THORNDIKE. 



human consciousness, but it is justified chiefly by its harmony 

 with the view that conception, the faculty of having general 

 notions, has been naturally selected by reason of its utilit}^ 

 The first thing is for an animal to learn to react alike only to 

 things which resemble each other in the essential qualities. On 

 an artificial, analytic basis, feelings of abstract qualities might 

 grow out of reacting alike to objects similar in such a respect 

 that the reaction would be useless or harmful. But in the actual 

 struggle for existence, starting with the mammalian mind as we 

 have found it, you will tend to get reactions to the beneficial 

 similarities by selection from among these so-called mistakes, 

 before you get any general fa atlty of noticing similarities. In 

 order that this faculty of indifferent reaction to different things 

 shall grow into the useful faculty of indifferent reaction to dif- 

 ferent things xvhich have all some quality that makes the reaction 

 a fit one, there must be a tremendous range of associations. 

 For a lot of the similarities which are non-essential have to be 

 stamped out, not by a power of feeling likeness, but by their 

 failure to lead to pleasure. With such a wide range of asso- 

 ciations we may get reactions on the one hand where impulses 

 have been connected with one particular sense-impression be- 

 cause when connected with all others they had failed to give 

 pleasure, and on the other hand reactions where an impulse has 

 been connected with numerous different impressions possessing 

 one common quality, and disconnected with all impressions, 

 otherwise like these, which fail to have that one quality. 



Combined with this multiplication of associations, there is, 

 I think, an equally important factor, the loosening of the ele- 

 ments of an association from one another and from it as a 

 whole. Probably the idea of the look of the loop or lever or 

 thumb-latch never entered the mind of any one of my cats 

 during the months that they were with me, except when the 

 front end of the association containing it was excited by putting 

 the cat into the box. In general, the unit of their consciousness, 

 apart from impulses and emotions, is a whole association-series. 

 Such soil cannot grow general ideas, for the ideas, so long as 

 they never show themselves except for a particular practical 

 business, will not be thought about or realized in their nature 



