lO ESSAYS IN PHILOSOPHY 



they have left the province of their sciences, and 

 the very bounds of all science as such. 



Of course, there is no longer any question at all 

 as to the reality of evolution as a fact, within the 

 specific region where it has been the subject of 

 scientific inquiry. There is no question, either, of 

 the use and importance of the hypothesis of evolu- 

 tion as a method of science, in that same definite 

 and tested region. On this matter, it is the business 

 of scientific experts alone to discover and to speak, 

 and it is the privilege as well as the duty of philoso- 

 phers, as of other people not experts in science, to 

 listen to what the men of science report, and to 

 accept it as soon as it comes with their settled con- 

 sensus. But whatever some men of science may 

 do in the way of philosophical speculation, science 

 makes no claim whatever that evolution goes a hair's 

 breadth farther than its scientific evidences carry it; 

 and hitherto these evidences are strictly confined 

 to the morphology and the physiology of living 

 beings, and of living beings only — to the thread 

 of descent by reproduction, convincingly traceable 

 by observation and experiment from the lowest 

 forms of plant life to the highest of animal.^ 



1 It is of course not ignored here that the entire series of physio- 

 logical phenomena is everywhere accompanied by a " parallel " or con- 

 comitant series of psychic or "mental ^^ phenomena, which coordinately 

 undergoes an evolution of its own. In fact, one might say, with many 



