8 INTRODUCTION. 



than the rapidity of its conquest is the authority with 

 which the doctrine of development has seemed to 

 speak to the most authoritative minds of our time. 

 Of those who are in the front rank, of those who by 

 their knowledge have, by common consent, the right to 

 speak, there are scarcely any who do not in some form 

 employ it in working and in thinking. Authority 

 may mean little; the world has often been mistaken; 

 but when minds so different as those of Charles 

 Darwin and of T. H. Green, of Herbert Spencer andof 

 Robert Browning, build half the labors of their life on 

 this one law, it is impossible, and especially in the ab- 

 sence of any other even competing principle at the pres- 

 ent hour, to treat it as a baseless dream. Only the 

 peculiar nature of this great generalization can account 

 for the extraordinary enthusiasm of this acceptance. 

 Evolution has done for Time what Astronomy has 

 done for Space. As sublime to the reason as the 

 Science of the Stars, as overpowering to the imagina- 

 tion, it has thrown the universe into a fresh perspec- 

 tive, and given the human mind a new dimension. 

 Evolution involves not so much a change of opinion as 

 a change in man's whole view of the world and of life. 

 It is not the statement of a mathematical proposition 

 which men are called upon to declare true or false. It 

 is a method of looking upon Nature. Science for cent- 

 uries devoted itself to the cataloguing of facts and 

 the discovery of laws. Each worker toiled in his own 

 little place — the geologist in his quarry, the botanist 

 in his garden, the biologist in his laboratory, the 

 astronomer in his observatory, the historian in his 

 librar}^ the archaeologist in his museum. Suddenly 

 these workers looked up ; they spoke to one another ; 



