THE SCIENCE OF LIFE 



times Democritus and Lucretius traced all phenomena 

 to the movements of dead atoms, as did also Holbach 

 and Lamettrie in the eighteenth century. This view 

 is held to-day by most chemists and physicists. They 

 regard gravitation and chemical affinity as a mere me- 

 chanical movement of atoms, and this, in turn, as the 

 general source of all phenomena ; but they will not allow 

 that these movements necessarily presuppose a kind of 

 (unconscious) sensation. In conversation with distin- 

 guished physicists and chemists I have often found that 

 they will not hear a word about a "soul" in the atom. 

 In my opinion, however, this must necessarily be as- 

 sumed to explain the simplest physical and chemical 

 processes. Naturally I am not thinking of anything like 

 the elaborate psychic action of man and the higher 

 animals, which is often bound up with consciousness; 

 we must rather descend the long scale of the develop- 

 ment of consciousness until we reach the simplest pro- 

 tists, the monera (chapter ix.). The psychic activity of 

 these homogeneous particles of plasm (for instance, the 

 chromacea) rises very little above that of crystals; as in 

 the chemical synthesis in the moneron, so in crystalliza- 

 tion we are bound to assume that there is a low degree of 

 sensation (not of consciousness), in order to explain the 

 orderly arrangement of the moving molecules in a defi- 

 nite structure. 



The prejudice against theoretical materialism (or mate- 

 rialistic monism) which still prevails so much is partly 

 due to its rejection of the three central dogmas of 

 dualist metaphysics, and partly to a confusion of it 

 with hedonism. This practical materialism in its ex- 

 treme forms (as Aristippus of Cyrene and the Cyrenaic 

 school, and afterwards Epicurus, taught it) finds the 

 chief end of life in pleasure — at one time crude, sensual 

 pleasure, and at others spiritual pleasure. Up to a 

 certain point, this thirst for happiness and a pleasant 



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