INSTINCT 49 



large extent. His calculating powers are acquired, his 

 aptitude for acquiring them is inborn. It is very necessary 

 to keep this difference clearly before the mind in considering 

 inborn and acquired characters. 



It is impossible here to deal with the instincts of man 

 in any detail. It is certain that man possesses but few 

 unmodified instincts, but inquiry into this matter is still 

 in a state of considerable confusion. Undoubtedly the child 

 possesses the instinct to suck. 



There can be little doubt as to the sexual instinct. 

 Psychologists are not agreed as to how the play of young 

 animals ought to be regarded. Play has been attributed 

 to a surplus of nervous energy in the young animal, which, 

 being tended by its parents, is not obliged to seek its own 

 livelihood. This theory was first propounded by the poet 

 Schiller, and was elaborated by Herbert Spencer. Another 

 theory 1 supposes that the play of young animals renders 

 them skilful in various ways -that will be useful in later 

 life. The kitten plays with various dead objects and thus 

 trains itself in rapid movements of a kind that will be 

 useful when it is obliged to seek its own prey. According 

 to this theory, play is not exactly an instinct, but is due to 

 a premature ripening of other instincts that will subse- 

 quently be useful to the individual. A more recent theory 2 

 suggests that play is "a peculiarly modified form of the 

 combative instinct." This theory assumes pugnacity as 

 the true instinct, and play as a modification due to an innate 

 tendency to rivalry. 



It is exceedingly difficult for the biologist and student of 

 heredity to fall in with any of these views. That play is the 

 result of superfluous energy is directly contrary to the well- 

 recognised parsimony of nature, and it is inconceivable that 



1 Groos, Karl, Die Spiele der Thiere, Jena, 1898, translation E. L. Baldwin, 

 New York, 1906 ; Die Spiele der Menschen, Jena, 1899, translation E. L. Baldwin, 

 New York, 1901. 



2 M'Dougall, William, An Introduction to Social Psychology, Methuen, 

 London, 1908. 



D 



