EVOLUTIONAEY PEINCIPLES 29 



Biology, having entered upon the evolutionary stage, brings 

 mankind with it. We are therefore justified in expecting 

 that anthropology will tend more and more to become an 

 evolutionary science, developing a method and a nomenclature 

 of its own. But anthropology includes psychology, morality, 

 history in all its branches whatever constitutes mankind. 

 These subordinate departments must therefore submit to 

 treatment upon evolutionary principles, unless it should be 

 proved that the old distinction between mind and matter has 

 to be maintained, and that evolution is only useful in 

 explaining the laws of material development. If such a 

 conclusion be arrived at, it will involve the hypothesis that 

 Nature, including living creatures, pursues a process from the 

 simple to the complex, but that mind is acquired from without 

 at a certain point of that process by some living things which 

 j,re a product of the process. In other words, mind will have 

 to be accepted as destroying the coherence of the universal 

 order. 



Our growing sense of cosmic unity renders such a dualistic 

 hypothesis improbable. The comparative study of intelligence 

 in animals and men does not tend to confirm it. Meanwhile, 

 what is known about the advance of mankind from savagery 

 to civilisation recent investigation into the origins of 

 mythology, language, and religion, together with the remark- 

 able additions made by Francis Galton to the science 

 of heredity encourage the expectation that mind in its 

 historical development will eventually be treated upon 

 evolutionary principles. 



These observations are intended to introduce certain 

 mental phenomena which invite an evolutionary explanation. 

 The cases I mean to discuss have this point in common : A 

 certain type of literature or art manifests itself, apparently by 

 casual occurrence, in a nation at a given epoch. If favourable 

 conditions for its development are granted, it runs a well- 

 defined course, in which every stage is connected with pre- 

 ceding and succeeding stages by no merely accidental link ; 

 and when all the resources of the type have been exhausted, 

 it comes to a natural end, and nothing but debris is left of it. 



