PREFACE TO THE FIRST EDITION. 



SOME time ago we published an essay entitled 

 "Instinct and Intelligence in the Animal King- 

 dom," examining in detail the concepts of instinct 

 and intelligence, with their application to animals. 

 The discussion showed that intelligence, is the spiritual 

 power of abstraction, and not the mere faculty of 

 forming complex sense-representations ; for the laws 

 of association in sense-perceptions belong to the sphere 

 of instinctive sensitive life and not to spiritual intelli- 

 gence. Now, what modern animal psychology terms 

 "intelligence of animals," is nothing but inborn 

 instinct, raised to a higher level of perfection by the 

 individual's sensuous experience. This, in its turn, 

 is based on the very same laws of association of sense- 

 representations. Hence, there is no reason for ascrib- 

 ing to animals intelligence in the stritt sense. Indeed, 

 our reasoning led us to take a further step, and we 

 proved that animals have no intelligence at all. If 

 they were gifted with a spiritual power of abstraction, 

 it would necessarily be manifested in their outward 

 actions, especially by the formation of an arbitrary 

 phonetic or graphic language. Animals, however, 

 have no language; hence, they have no intelligence. 

 Besides, we have shown in the same essay that 

 the manifestations of the psychic life, both of higher 

 and of lower animals, are to be judged according to 

 one and the same critical standard. The anatomical 



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