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io 4 MIND IN EVOLUTION CHAP. 



two perfectly separate portions. Our division is analytical. 

 It is a separation of functions which in working are com- 

 bined, and an attempt in resolving a joint product to 

 assign to each what is its due. This must be borne in 

 mind in any attempt to estimate the part played by 

 instinct in human life. The older psychology expressed 

 the contrast between the human and the animal mind in 

 terms of the opposition between intelligence and instinct. 

 Recent psychology has emphasised the part of instinct in 

 human nature. But to begin with, it must be clear that 

 in human nature there is very little that is pure instinct. 

 Man is always capable of reflection. Even if instinct sets 

 him the aim he can appreciate it, distinguish what is 

 essential from what is indifferent, and vary the means that 

 he uses indefinitely. Nor is this all. As a rational being 

 he is capable of criticising the instinctive interest, if such 

 we are to call it, itself. He brings it in relation to his 

 life as a whole and to the lives of other people. It is 

 modified by the social atmosphere in which he grows up. 

 It takes its particular shape from the traditions of his society, 

 his class, his school, his family. It never governs him as 

 long as he remains mentally and morally sane, but is 

 merged in that moral organism of many inter-acting parts 

 which is called the self. Not only the separate parts but 

 the characteristic unity of each individual what used to be 

 called the temperament that by which the several 

 elements are interfused is part of the hereditary structure, 

 though, like everything else that is inherited, it grows 

 under the plastic hand of experience. Nor is the behaviour 

 determined by the kind of interests popularly called 

 instinctive specifically defined and fixed, prior to ex- 

 perience, apart from a few exceptional elements. The 

 range of behaviour determined by what is loosely called 

 the sexual instinct, for example, is of extreme width. It 

 may be said to cover the frenzy of physical passion, the 

 romantic devotion which would lead a man to risk his 

 neck for a girl, equally with the expansion or possibly the 

 reserve provoked by contact with the other sex, or the 

 deference and attention which social tradition, acting upon 

 some innate tendency, has developed. In relation to 



