124 THE PHILOSOPHY OF BIOLOGY 



the latter the functions of the healthy body might 

 still proceed automatically, and if the soul influenced 

 action it actuated an existing mechanism, and without 

 that mechanism it could not act, though the mechanism 

 might act without the soul. Thought, understanding, 

 feeling, will, imagination, memory, these were the 

 prerogatives of the soul, and not those of the automatic 

 body. But the movements of the latter, even volun- 

 tary movements, depended on a proper disposition 

 of organs, and without this they were wanting or 

 imperfect. 



Thus to a thoroughgoing mechanism Descartes 

 joined a spiritualistic and immortal entity ; and this, 

 to the materialism of the middle of the nineteenth 

 century, was the blemish on his philosophy. Now of 

 all men who have ever lived he is probably the one 

 who has most profoundly influenced modern thought 

 and investigation : to us what he wrote seems strangely 

 modern, and this apparently arbitrary association of 

 spiritualistic and materialistic elements in life seems 

 almost the most modern thing in his writings. Being, 

 he said, was indeed thought, but how could he derive 

 thought from his clockwork body, with its valves and 

 conduits and wires ? No more can we derive con- 

 sciousness from the wave of molecular disturbance 

 passing through afferent nerve and cerebral tracts. 

 We must account for all the energy of this disturbance, 

 from its origin in the receptor organ to its transforma- 

 tion into the wave of chemical reaction in the muscle, 

 and we must regard its transmission as a conserva- 

 tive process. But how does the state of consciousness 

 accompanying the passage through the cortex of this 

 molecular disturbance come into existence ? None of 

 the energy of the nerve disturbance has been trans- 

 formed into consciousness : the latter is not energy 



