184 EVOLUTION 



which are "physical" or "vital," to different 

 schools, of materialistic or idealistic leanings 

 respectively, albeit physical rather than 

 biological in either case. Our present point 

 is that before inquiring into the secret of the 

 organism "Life" hi the innermost and 

 organismal sense we must seek a deeper 

 appreciation of the process of living. What 

 then is this? On the one hand there is 

 the Environment in its action upon the 

 organism; and on the other the Organism in 

 its reaction to and action upon the environ- 

 ment; the dynamic relation, in its twofold 

 aspect, is called Function. 



THE EVOLUTION IDEA: ITS HISTORY. 

 Before we seek to relate the various theories 

 of evolution factors that have been suggested 

 to the three categories of Biology Organism, 

 Function, Environment it may conduce to 

 clearness to consider for a little the general 

 "doctrine of descent." 



While it is true, as Professor Osborn puts 

 it, that "Before and after Darwin" will al- 

 ways be the "Ante et post urbem conditam" 

 of biological history, it is also true that the 

 general idea of organic evolution is very 

 ancient. Several of the Greek philosophers 

 looked upon Nature as having developed, 

 and as being still in process of change. Aris- 

 totle seems to have recognized an ascending 



