xx INTR OD UCTION 



tion and unnatural interpretation in this field, yet the false 

 hopes of the alchemist and his unscientific methods show 

 that even chemistry has had to grow away from a mass of 

 ignorant belief that prevented its being worthy the name of 

 science. 



But the biological sciences were still slower to come to 

 their true position as dignified science. Here was the last 

 stronghold of the supernaturalist. Thrust out from the field 

 of " physical science " it was in the phenomena of life that the 

 last stand was made by those who claim that supernatural 

 agency intervenes in nature in such a way as to modify the 

 natural order of events. 1 When Darwin came to dislodge 

 them from this, their last intrenchment, there was a fight, 

 intense and bitter, but, like all attempts to stay the progress 

 of human knowledge, this final struggle of the supernatural- 

 ists was foredoomed to failure. The theory of evolution has 

 taken its place beside the other great conceptions of natural 

 relations, and largely through its establishment biology has 

 become truly a science with a large group of phenomena con- 

 sistently arranged and properly classified. The discussion 

 which followed the publication of Darwin's " Origin of Spe- 

 cies " lasted for nearly a generation, but it is now practically 

 closed, so far as any attempt to discredit evolution as a 

 true scientific generalization is concerned. Scientists are no 



1 The author believes that all nature is controlled by an intelligent Providence, 

 and that every phenomenon of nature is either natural or supernatural, according to 

 one^ point of view. A book upon the philosophical bearing of the theory of evolu- 

 tion might treat of the supernatural aspects of nature. It is my purpose, however, 

 to discuss only the natural aspects. But it is important to insist that all our scien- 

 tific knowledge of natural phenomena points to the conclusion that these phenomena 

 are orderly and self-consistent, and that the supernatural and natural are never in 

 conflict ; in other words, that natural phenomena are capable of being studied and 

 classified. 



