22 



each one of which, as well, doubtless, as in other works by the 

 same writers, he would have become thoroughly familiar with 

 the doctrine of Association. 



In part, as a result of the development of the theory of 

 Association, Darwin found conditions very favourable for the 

 introduction of the theory of Natural Selection. Natural 

 Selection itself, in what might be called an embryonic form, is 

 not an idea altogether foreign to the theory which had been 

 developing with the work of John Stuart Mill and Alexander 

 Bain. If we keep in view the association and utilitarian 

 psychology of Darwin's time, it is not unlikely that the idea 

 of utility the criterion of our actions in the moral sphere 

 and, on his own admission, the Malthusian theory of popula- 

 tion, should have influenced Darwin as a Natural Scientist, 

 in formulating a theory for the great mass of material which 

 he had gathered, and thus have suggested the idea of the 

 preservation of the most useful modifications of structure and 

 habit that such useful modifications should be the criterion 

 of events in the sphere of biology, and hence the doctrine of 

 the 'survival of the fittest'. 



III. DEVELOPMENT OF EVOLUTION THEORY 

 PRE-DARWINIAN. 



We have thus been led up to Darwin from the side of the 

 mental sciences as represented in the Association School 

 of psychologists. We have seen that for these men a know- 

 ledge of physiological processes in the human organism, and 

 especially in the nervous system, was of fundamental import- 

 ance. For the better understanding of the relation existing 

 between physiological and psychological phenomena, which will 

 be considered hereafter in some detail, attention may also be 

 drawn to the development on the side of physiology which 

 occurred prior to the time of Darwin and his theory of Natural 

 Selection. The main outlines of that development may be 

 obtained from such general works as that of H. F. Osborn, 

 'From the Greeks to Darwin', 1 and of Max Verworn, in the 

 first part of his 'General Physiology'. 2 



1. ANAXAGORAS, DEMOCRITUS, EMPEDOCLES, ARISTOTLE, 

 AUGUSTINE, HARVEY, BUFFON, BONNET. 



Like all other great questions, Evolution has had a variety 

 of forms, but the fundamental idea, that of the descent of 



a 2nd ed., 1896. 



22nd ed., 1897. Ch. I, Sec. II. 



