12 Chapter IV. 



To those who disapprove of our distinction of in- 

 stinct and intelligence may be added Prof. W. M. 

 Wheeler of Texas University. He has developed his 

 views in a recent paper on "The compound and mixed 

 nests of American ants." 1 Admitting our psychological 

 explanation of nearly all the facts observed in ant life, 

 Prof. Wheeler maintains that he cannot adopt either 

 our "psychological definitions" or our "psychogenetic 

 reservations." 



Let us examine his reasons. Prof. Wheeler does 

 not admit our distinction between instinct and intelli- 

 gence, because he thinks that we take the term "in- 

 stinct" in too wide a sense, by including under it 

 "both the instinct and intelligence of other authors." 

 Therefore he prefers to restrict the term intelligence to 

 those actions of the animal "which imply choice on the 

 part of the individual organism." 



We included, it is true, under "instinct sensu lato" 

 not only those sensitive activities which are directly 

 based on inherited mechanisms, but those also which are 

 due to the sense experience of the animal. Still, we 

 have never confounded the two. Otherwise we could 

 not have restricted the term "instinctive sensu proprio" 

 to sensitive activities which are based on inherited 

 mechanisms. On the other hand we maintain that 

 these two kinds of activities are not and cannot be 

 essentially different, because all actions that are in- 

 stinctive sensu proprio necessarily contain at least one 

 element of sensile experience, the sensual agreeableness 

 of the respective action (vide Chapt. 2). Therefore 

 both kinds of activity belong to the same general class 



!) "American Naturalist," 35, 1900, No. 418, p, 808 ff. 



