1 



TKlVKKSrVYOF 



US 



BIOLOGY. 



BOOK I. 



OF ORGANISED MATTER IN GENERAL. 



CHAPTER I. 



CONSTITUTION OP MATTER. UNITY OF SUBSTANCE IN THE ORGANIC 



WORLD AND IN THE INORGANIC WORLD. 



THE sciences of observation demand at the outset from him who 

 wishes to cultivate them an act of faith^ Though it is per- 

 fectly incontestable that the exterior world manifests itself to 

 us solely by exciting in our mind an incessant series of phe- 

 nomena of consciousness, of phenomena called subjective, we are 

 nevertheless compelled, unless we wish to plunge into the doubt 

 applauded by Pyrrho and Berkeley, to believe our senses as 

 honest and sincere witnesses when they signalise to us the exist- 

 ence, apart from our own being, of a vast material universe, the 

 elements whereof, without pause in movement, awaken in us, by 

 acting on our organism, impressions, sensations, and consequently 

 ideas and desires. 



The exterior world exists independently of our conscious life ; 

 it was when as yet we were not ; and it will be when we are no 



