498 PRIMARY FACTORS OF ( RGANIC EVOLUTION. 



organs when once called into existence is due to stimuli 

 similar to those which affect the motions of the limbs 

 of the higher animals, is altogether probable. What- 

 ever be its nature, the preliminary to any animal move- 

 ment which is not automatic, is an effort. And as no 

 adaptive movement is automatic the first time it is per- 

 formed, we may regard effort as the immediate source 

 of all movement. Now, effort is a conscious state, and 

 is a sense of resistance to be overcome. When an act 

 is performed without effort, resistance has been over- 

 come, and the mechanism necessary for the performance 

 of the act has been completed. The stage of automa- 

 tism has been reached. At the inception of a new 

 movement resistance is necessarily experienced. It is 

 generally believed that a mental state, as a sensation 

 or a desire, which may or may not stimulate a^ational 

 process as an intervening element in the circuit, is 

 concerned in overcoming this resistance. 



A different view is held by certain physiologists and 

 ritietaphysicians, as e. g. Wundt and Hoffding. Hux- 

 ley thus states his opinion in his Belfast address of 

 1874,^ a pj-opos of Descartes's doctrine that all animals, 

 below man are automata. "The consciousness of 

 brutes would appear to be related to the mechanism of 

 their body simply as a collateral product of its work- 

 ing, and to be as completely without any power of 

 modifying that working as the steam-whistle which 

 accompanies the work of a locomotive-engine is with- 

 out influence on its machinery. Their volition, if they 

 have any, is an ejnotion indicative of physical changes, ?iot 

 a cause of such changes.''' (Italics mine.) In other 

 words, stimulus excites conscious states, but the state 

 thus produced has no influence on the resulting act. 



^Scientific Culture and Oilier Essays, p. 243. 



