96 THE RIDDLE OF THE UNIVERSE. 



— in a series of distinguished papers in the first 

 volumes of the Archiv fur pathologische Anatomie, 

 which he founded. The most important of these 

 articles, and the one in which he most clearly 

 expresses his monistic views of that period, is that on 

 " The Tendencies Towards Unity in Scientific Medicine " 

 (1849). It was certainly not without careful thought, 

 and a conviction of its philosophic value, that Virchow 

 put this " medical confession of faith " at the head 

 of his Collected Essays on Scientific Medicine in 1856. 

 He defended in it, clearly and definitely, the funda- 

 mental principles of monism, which I am presenting 

 here with a view to the solution of the world-problem ; 

 he vindicated the exclusive value of empirical science, 

 of which the only reliable sources are sense and 

 brain activity ; he vigorously attacked anthropological 

 dualism, the alleged "revelation," and the transcen- 

 dental philosophy, with their two methods — " faith and 

 anthropomorphism." Above all, he emphasized the 

 monistic character of anthropology, the inseparable 

 connection of spirit and body, of force and matter. 

 " I am convinced," he exclaims, at the end of his 

 preface, "that I shall never find myself compelled 

 to deny the thesis of the unity of human nature." 

 Unhappily, this " conviction " proved to be a grave 

 error. Twenty-eight years afterwards Virchow repre- 

 sented the diametrically opposite view : it is to be 

 found in the famous speech on " The Liberty of 

 Science in Modern States," which he delivered at the 

 Scientific Congress at Munich in 1877, and which 

 contains attacks that I have repelled in my Free 

 Science and Free Teaching (1878). 



In Emil Du Bois-Keymond we find similar con- 

 tradictions with regard to the most important and 



