44 ESSAYS OF A BIOLOGIST 



the following main ways. First, he has the power 

 of thinking in concepts ; in other words, his power 

 of learning by experience is not always conditioned 

 directly by the accidents of his own life, as is the case 

 with animals endowed only with associative memory, 

 but he can, by reaching the general from the special, 

 attain to the possibility of dealing with many more, 

 and more complicated, eventualities. Next, by means 

 of speech, writing, and printing, he has developed a 

 new mode of inheritance. ^ Each community, and 

 indeed humanity as a whole, transmits its peculiarities 

 to later ages by means of tradition, using that word 

 in its largest sense. Physical inheritance of the same 

 type as in all higher animals and plants is the necessary 

 basis, but the distinctive characters of any civilization 

 are based on this new tradition-inheritance. Thirdly, 

 the type of mind which has been evolved in man is 

 much more plastic — a much more elastic and flexible 

 mechanism than any tool previously evolved by life 

 for handling the problems of existence. As a con- 

 sequence of this we have the substitution of general 

 educability for specific instincts. For the power of 

 performing comparatively few actions smoothly and 

 without trouble, there is exchanged the possibility 

 of a vastly increased range of action, but one which 

 has to be learnt. As another consequence, man has 

 come by the power — impossible to any other organism 

 — of leading what is to all intents and purposes a 

 ^ See Carr-Saunders, ""22, 



