THE WONDERS OF LIFE 



extinction of it under chloroform or ether is an analo- 

 gous fact. Again, the familiar phenomena of the dream, 

 the deviations from normal consciousness, hallucinations, 

 delusions, etc., must convince every impartial thinker 

 that these mental functions are not of a metaphysical 

 character, but physical processes in the neuroplasm of 

 the brain, and thoroughly dependent on the law of 

 substance. 



In complete contrast to this natural monistic con- 

 ception of the human mind, which is, in my opinion, 

 definitely established by nineteenth-century science, we 

 have the older dualistic estimate of it which is still wide- 

 ly accepted both by unlearned and learned, especially 

 metaphysicians and theologians. I have already dealt 

 in the Riddle (chapter xi.) with the grounds for this be- 

 lief in an immaterial soul, and expressed my conviction 

 that "the belief in the immortality of the human soul 

 is in flagrant contradiction to the soundest empirical 

 principles of modern science." I must refer the reader 

 to what I said there about thanatism and athanatism, 

 only reminding him once more of the immense influence 

 of the Kantist philosophy in maintaining this belief in 

 the spirituality of the soul. Kant derived from the 

 introspective study of his own gifted mind an extremely 

 high estimate of human reason, and he fallaciously trans- 

 ferred this estimate to the human mind generally. He 

 did not perceive that it is either wholl}^ wanting in the 

 savage, or does not rise much above the stage which has 

 been reached by the intelligence of the dog, horse, ele- 

 phant, and other advanced animals. 



Modern anthropogeny has raised the theory of evolu- 

 tion to the rank of an historical fact. All the various 

 organs of our body resemble those of our nearest rela- 

 tives, the anthropoid apes, in their structure and com- 

 position. They only differ from them in details of form 

 and size, which are determined by inherited variations 



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