462 



Animal Life and Intelligence. 



seen that, in association with inhibition, the faculty of 

 volition has been developed. And we may now notice that 

 the postponement or suppression of action is one of the 

 criteria of intelligent as opposed to instinctive or impulsive 

 activities. This is, however, subordinate to the criterion 

 of novelty and individuality. 



Granting, then, that an action is shown to be intelligent 

 from the novelty of the adjustments involved, and from the 

 individuality displayed in dealing with complex circum- 

 stances (instinctive adjustments being long-established and 

 lacking in originality), we may say that the level of intelli- 

 gence is indicated by the complexity of the adjustments ; 

 their precision ; the rapidity with which they are made ; 

 the amount of prevision they display ; and in their being 

 such as to extract from the surrounding conditions the 

 maximum of benefit. 



Before closing this chapter, I will give a classification of 

 involuntary and voluntary activities : — 



In the involuntary acts classed as automatic and reflex, 

 the initiation and the result may be accompanied by con- 

 sciousness, but the intermediate mental link which answers 

 to the motive in higher activities is, I think, unconscious. 

 In habitual and instinctive activities the consciousness of 

 the percept and the impulse may in some cases have 

 become evanescent, or, to use G. H. Lewes's phrase, have 

 lapsed. In the case of some instincts, originating by the 

 natural selection of unintelligent activities, the perceptual 



