xiv INTRODUCTION 



was tlie ancestor of man. And a biologist who can 

 tell us nothing about man is neglecting his fairest field. 



Conversely history and social science will rest on a 

 firmer basis when their students recognize that many 

 human laws and institutions are heirlooms, the attain- 

 ments, or direct results of attainments, of animals far 

 below man. "We are just beginning to recognize that 

 the study of zoology is an essential prerequisite to, and 

 firm foundation for, that of history, social science, phi- 

 losophy, and theology, just as really as for medicine. 

 An adequate knowledge of any history demands more 

 than the study of its last page. The zoologist has been 

 remiss in not claiming his birthright, and in this re- 

 spect has sadly failed to follow the path pointed out 

 by Mr. Darwin. 



For palaeontology, zoology, history, social and politi- 

 cal science, and philosophy are really only parts of one 

 great science, of biology in the widest sense, in distinc- 

 tion from the narrower sense in which it is now used to 

 include zoology and botany. They form an organic 

 unity in which no one part can be adequately under- 

 stood without reference to the others. You know 

 nothing of even a constellation, if you have studied 

 only one of its stars. Much less can the study of a 

 single organ or function give an adequate idea of the 

 human body. 



Only when we have attained a biological history can 

 we have any satisfactory conception of environment. 

 As we look about us in the world, environment often 

 seems to us to be a chaos of forces aiding or destroy- 

 ing good and bad, fit and unfit, alike. 



But our history of animal and human progress shows 

 us successive stages, each a little higher than the pro- 



