ii6 MEMORIAL SKETCH. 



ture, and the physical geography both of the deep and 

 inland seas. And a third, growing in bulk and importance, 

 related to the old questions of psychology and religious 

 philosophy, on which he had been silently pondering since 

 1854. He entered the field once more with papers on the 

 " Physiology of the Will " (1871), and "Common Sense" 

 (February, 1872). In the summer of 1872 he presided 

 over the meeting of the British Association for the Ad- 

 vancement of Science at Brighton, and took as the theme 

 of his address the interpretation of nature by man.* A 

 succession of articles on kindred topics followed in the 

 next three years, while he devoted himself to the project 

 which he had long entertained, of enlarging the outline of 

 .his chapters on the nervous system in the fourth edition 

 of his " Human Physiology." This was completed in 

 1874, under the title of "Principles of Mental Physiology, 

 with their Applications to the Training and Discipline of 

 the Mind, and the Study of its Morbid Conditions." Into 

 this book he poured much of his most earnest thought, his 

 observations on human character, his meditations on the 

 conduct of life. Starting from the functions of the dif- 

 ferent portions of the nervous system,")* he sketched the 

 natural history of thought and feeling, and discriminated 

 with the added precision of twenty years' consideration, 

 between the two spheres of automatic action and volitional 

 control. Reflection had only confirmed him in the views 

 which his physiological inquiries had originally generated ; 

 and he had accumulated a large store of illustrations, which 

 threw new and suggestive lights on the meaning of many 

 of the commonest experiences. The attention which he 

 had bestowed on many abnormal mental phenomena, and 



* See below, p. 185. 



t Subsequent investigations have thrown doubt on some of his positions, 

 but it is not perhaps too much to say that in the present state of knowledge 

 the view which he offers still remains more coherent than any other. 



