THE COMING OF EVOLUTION 205 



" being right is no excuse whatever for holding an 

 opinion which has not been based on any adequate 

 consideration of the facts involved in it." As in so 

 many branches of knowledge, the time was not ripe 

 for the Greeks to do more than formulate the problem, 

 and make avowedly philosophic guesses at its solution. 

 Indeed, it needed two thousand years of time, and 

 the labours of many quiet and unphilosophic physio- 

 logists and naturalists, before sufficient experimental 

 and observational evidence could be collected to make 

 the idea of evolution worth examining by science. 

 It is a good illustration of the true scientific attitude 

 of suspension of judgment in face of inconclusive 

 evidence, that for the most part naturalists left the 

 idea of evolution to the philosophers, and that, till 

 Darwin and Wallace published their simultaneous 

 work, the balance of scientific opinion was clearly 

 against the theory. On the other hand, the philo- 

 sophers also played their true part in maintaining 

 speculation about a theory not ripe for scientific 

 treatment, in keeping open a question of paramount 

 importance, and in formulating solutions which, in due 

 time, might serve as working hypotheses for the men 

 of science with whom lay the ultimate decision. 

 Hence it is in the nature of the case that, when, in 

 the revival of learning, the idea of evolution once 

 more appears, it is to be found chiefly in the writings 

 of Bacon, Descartes, Leibniz and Kant, while the men 

 of science were only slowly working far behind at 

 facts which eventually would point in the same direc- 

 tion, through the embryology of Harvey and the 

 system of classification of Ray. Moreover, some of 

 these philosophers speculated on the possibility of 



