The Intimate Causes of Old Age. 189 



It was an idea that could hardly have found place until 

 the Origin of Species and the Descent of Man were 

 written, since it is the logical complement, the sequence 

 of these doctrines of nature. It could hardly have come be- 

 fore, save, perhaps, as visional in the brain of a philosopher. 

 But following the epoch of Darwin, Huxley, and Tyndall 

 in England ; of Humboldt, Goethe, Helmholtz, Haeckel, 

 Weissmann in Germany, and their biological contempora- 

 ries in France, America, and other lands, the achievement 

 of immortal life follows as the keystone of the arch, the 

 climax, the perfected fruit and flower of the evolution of 

 life on the earth. Follows from the natural growth of 

 knowledge in the human brain, presenting itself in the 

 light of a great achievement. For, with the dawn of this 

 new century, we have wakened to the hard fact that 

 whatever we have here on the earth we must achieve for 

 ourselves. 



More life, longer, happier, personal life, idealized as 

 immortal life, has been the dream of all the human ages. 

 It is the Voice of nature — nature that everywhere makes 

 oath that to live is better than to die ; and that life even 

 under hard conditions is worth preserving. This is the 

 " instinct " of the eell-of-life, both as a protozoon and 

 when united and organized in the metazoon ; it is the 

 voice of the cell, heard crying up from its lowly depths in 

 the tissues of the organism. It is the faith of the sub- 

 conscious life in us. 



