OF NATURE. 601 



of which ' The Eiddle of the Universe ' is one of the 

 latest and best known. It cannot be said that philo- 

 sophically anything essential has been added by him to 

 the arguments advanced by Btichner on the one side 

 and by Du Bois Eeymond on tlie other. 



It is true that Haeckel brings in a great wealth of 

 illustrations largely derived from his own original work ; 

 also that he started with a full appreciation of the 

 Darwinian ideas of development, whereas his forerunner, 

 Btichner, introduced these ideas mostly only in the later 

 editions of his work. Otherwise it makes little diffier- 

 ence whether we call the underlying essence matter (with 

 Btichner) or substance (with Haeckel) ; and, if we com- 

 pare Haeckel's view with that of Du Bois Eeymond, we 

 find that both thinkers admit the necessity of introducing 

 into their conception of the ground of everything a 

 spiritual or psychical attribute without which they think 

 it impossible to approach the World-problem. This is a 

 distinct advance upon Btichner's apparently mechanical 

 view, — an advance through which both thinkers rise, 

 in a similar way to Herbert Spencer, above simple 

 materialism. As stated above, neither Btichner's nor 

 Haeckel's views have been taken seriously by philosophi- 

 cal thinkers, although both have had a marked influence 

 on popular thought and literature, especially in Germany. 

 The fact that their works are only incidentally mentioned 

 by historians of philosophy abroad may be traced to the 

 following causes. 



It is not an unusual thing to find that scientific 

 specialists who have attained to eminence through original 

 discoveries in definite lines of research or through theo- 



