390 Heredity. 



With regard to vital phenomena there is no such uniformity of 

 opinion. Many hold that the harmony of the functions which 

 support life in plants and animals cannot be merely the result of 

 the general laws of motion, and that it necessitates the hypothesis 

 of some principle distinct from the organism and subject to different 

 laws. It cannot, however, be denied that all these vitalist explana- 

 tions have a provisional character, that they yield daily to mechanical 

 explanations, and that it looks as though eventually their only stay 

 would be our ignorance. Furthermore, inasmuch as the quantity 

 of motion in the universe is invariable, the hypothesis of a force 

 possessed of the power of creating motion, of suspending it, and 

 varying it, is full of difficulties and contradictions. Hence the 

 conclusion which meets us at the end of all our scientific researches 

 is that ' we are warranted in bringing life under the laws of inor- 

 ganic matter, though there are some special processes peculiar to 

 life.' (Claude Bernard.) 



There is still less disposition to admit determinism in the order 

 of psychological phenomena. Yet whatever progress has been 

 made by experimental psychology during the past forty years real 

 progress, though as yet but little known consists in the investiga- 

 tion of laws that is to say, of invariable simultaneousness and 

 succession in other words of determinism. So recent is this study, 

 so little has been done, compared with what remains to do, that 

 psychological determinism necessarily finds many opponents and 

 few adherents. Yet it is contrary to all logic to hold that this 

 category of phenomena is not subject to determinism. In the 

 first place, perception, which is the necessary starting-point of all 

 conscious mental activity, is subject to physical and physiological 

 laws with which we are partially acquainted ; and we have seen 

 that every sensation is resolved by analysis into slight motions. 

 In the next place, intellectual activity (judgment, reason, memory, 

 imagination) is governed by the great law of association or of 

 habit, which is evidently only a form of determinism. Finally, as 

 regards even the voluntary act, we have seen that, besides being 

 subject to the law of habit, which reduces it to automatism, since 

 it is always determined by motives, it always enters, as far as 

 regards its empirical conditions, into the web of universal 

 mechanism. 



