The characteristics of life 



should some day be artificially repeated in 

 a laboratory, as Professor Schafer so con- 

 fidently expects — even this would imply the 

 guidance of the living chemist. But still, it 

 may be asked, what right have we to identify 

 life and mind; what right, for example, to 

 credit plants with souls, as Aristotle did? 

 The right that the principle of continuity 

 gives us. No sharp line can be drawn be- 

 tween plants and animals nor between higher 

 animals and lower. 



But here the advocate of Naturalism may 

 intervene. "Continuity is just as complete 

 regarded from below as it is regarded from 

 above," he may urge ; " and if so, surely the 

 proper method of investigation is to begin 

 with the simpler and earlier rather than with 

 the later and more complex." Not necessarily, 

 we must reply : all depends — as Plato pointed 

 out long ago — ^upon where the characters we 



