THE NATURE OF THE SOUL. 95 



leader of German philosophy, Immanuel Kant. The 

 young, severely critical Kant came to the conclusion 

 that the three great buttresses of mysticism — " God, 

 freedom, and immortality " — were untenable in the 

 light of "pure reason"; the older, dogmatic Kant 

 found that these three great hallucinations were 

 postulates of " practical reason," and were, as such, 

 indispensable. The more the distinguished modern 

 school of " Neo-Kantians " urges a " return to Kant " 

 as the only possible salvation from the frightful 

 jumble of modern metaphysics, the more clearly do 

 we perceive the undeniable and fatal contradiction 

 between the fundamental opinions of the young and 

 the older Kant. We shall return to this point later on. 

 Other interesting examples of this change of views 

 are found in two of the most famous living scientists, 

 R. Yirchow and E. Du Bois-Reymond ; the metamor- 

 phoses of their fundamental views on psychology 

 cannot be overlooked, as both these Berlin biologists 

 have played a most important part at Germany's 

 greatest university for more than forty years, and 

 have, therefore, directly and indirectly, had a most 

 profound influence on the modern mind. Rudolph 

 Yirchow, the eminent founder of cellular pathology, 

 was a pure monist in the best days of his scientific 

 activity, about the middle of the century ; he passed 

 at that time as one of the most distinguished repre- 

 sentatives of the newly-awakened materialism, which 

 appeared in 1855, especially through two famous works, 

 almost contemporaneous in appearance — Ludwig 

 Biichner's Matter and Force and Carl Yogt's Super- 

 stition and Science. Yirchow published his general 

 biological views on the vital processes in man — which 

 he took to be purely mechanical natural phenomena 



