BIOLOGICAL TIME 



when taken separately, when taken successively and as a 

 whole, they seem to reveal a special link. Some invisible 

 contingency appears to lead them in the path which they 

 follow and to impose the order in which they are bound. 

 The synthetic chemical actions of organization and of 

 nutrition thus manifest themselves as if they were dominated 

 by an impulsive force which governs matter, creates a 

 special chemistry appropriated to its end, and brings in 

 contact the blind reagents of the laboratory just as the 

 chemist himself would. We already know that this power 

 of evolution, inherent in the ovule which is to reproduce 

 the Hving being, covers the phenomena of generation as 

 well as those of nutrition. They both, therefore, possess 

 a basic evolutive character. 



'This power or property of evolution, which we can just 

 mention here, would alone constitute the quid proprium of 

 / life, for it is clear that this evolutive property of the egg, 

 which will produce a mammal, a bird, or a fish, is neither 

 physics nor chemistry. Vitalistic conceptions can no longer 

 reign over physiology as a whole. The evolutive force of 

 the egg and the cells is therefore the last stronghold of 

 vitahsm. In taking refuge behind it, however, it is clear 

 that vitalism transforms itself into a metaphysical concept 

 and destroys the last link which bound it to the physical 

 world and to physiological science. In stating that life is 

 the directing idea, or evolutive force of the organism we 

 simply express the idea of unity in the succession of all 

 morphological and chemical changes Unked together by the 

 germs from the beginning to the end of life. Our mind 

 grasps this unity as a concept which imposes itself, and we 

 explain it by a force. It would be a mistake, however, to 

 beHeve that this metaphysical force is active in the same 

 way as a physical force. This conceptual force does not 

 leave the intellectual realm in order to react upon the 

 phenomena for the explanation of which it was created. 

 Although an emanation of the physical world, it does not 

 act upon it retroactively. In brief, the metaphysical force 



