x INTRODUCTION 



fellows, Wallace, Haeckel, Hooker are still 

 with us; and later ones in increasing number. 

 Observing and thinking, thinking and observ- 

 ing; outdoor and indoor, and outdoor again; 

 that is a game at which we all can play; 

 with education and evolution alike mingled 

 in its process and in its winning. 



Evolution in astronomy, from Kant to 

 Lockyer; evolution in chemistry and physics, 

 from Lucretius to the alchemists, and thence 

 to Ramsay and his fellow-alchemists of to- 

 day; evolution in geology, from Leonardo and 

 Palissy to Lyell and Darwin and onwards 

 all these large retrospects of the history of 

 science are needed for a grasp of cosmic 

 evolution. Their impetus, their methods too, 

 have once and again impelled the student of 

 organic nature towards evolutionary inter- 

 pretations, and still do so; while the thought 

 of the physicist and of the naturalist are in- 

 creasingly of interest and suggestion towards 

 the distinctively human and social studies. 



Yet it was essentially in the very opposite 

 way that modern evolution doctrines really 

 originated; as a social theory, that of progress: 

 and this generally diffused spirit of the later 

 eighteenth century, and the earlier nine- 

 teenth, has both consciously and uncon- 

 sciously stimulated naturalist and physicist 

 towards their evolutionary inquiries and 



