CHAPTER XII 

 THE INTELLIGENCE OF MAMMALS 



"Le premiere partie de cet ouvrage de*montre que les betes sont 

 capable de quelques connoissances. Ce sentiment est celui du 

 vulgaire: il n'est combattu que par des philosophes, c'est a dire, 

 par des hommes qui d'ordinaire aiment mieux une absurdite qu'ils 

 imaginent, qu'une ve"rite* qui tout le monde adopt." CONDILLAC, 

 Train des Animaux. 



"The power of association over brutes is very evident in all the 

 tricks which they are taught; and the whole nature of each brute, 

 which has been brought up among others of the same species, is a 

 compound of instinct, his own observations and experiences, and 

 imitation of those of his own species." HARTLEY, Observations on 

 Man. 



"Animals pass from one imagination to another by the connection 

 which they have felt before; for example, when his master takes a 

 stick, the dog fears a whipping. And in many instances children 

 with the rest of mankind proceed nowise differently in their passages 

 from thought to thought." LEIBNITZ, New Essays Concerning 

 Human Understanding. 



Until quite recently most of our knowledge of the psy- 

 chology of mammals, as of other animals, was obtained 

 simply by watching them. In this way has been accumu- 

 lated a large fund of information concerning their instincts 

 and habits, and to a certain extent their general intelligence. 

 But in this as in other fields of investigation, the method of 

 experiment has come to be indispensable when the attempt 

 is made to study the phenomena analytically. There is of 

 course no especial magic in the experimental method; it is 

 simply a means of improving the conditions of observation. 

 And in animal psychology especially, the method may have 

 drawbacks which counterbalance some of its advantages. 



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