THE ORIGIN OF NERVES. 297 



the primitive lines of discharge we are able to trace in its 

 frame. Physical change, produced by disease, for example, 

 makes sad havoc in the mental estate of man, and may 

 obliterate entirely the intellectual existence of our species. 

 Is it any the less a reasonable theory to assume that on 

 changes of like, that is, of physical, kind, depend our 

 thoughts and ideas ; or that from habit and use, and their 

 effects on the brain-substance, new powers of mind and new 

 intellectual features may have arisen in the past, and are 

 now being continually evolved in the history of our race ? 



These declarations may possibly sound a little material- 

 istic in some ears ; but there is certainly less materialism 

 involved in the supposition that we are the creatures of habit 

 and circumstance acting upon our nervous centres, than 

 in theories of human life which begin their explanation of 

 man's mental and moral nature by assuming the inherited 

 and exceeding badness of the race. Whatever powers we 

 attribute to man must be shown to depend on the character 

 of his nerve-centres, and on the powers of these parts as 

 modified by ignorance, superstition, or animalism, or as 

 perfected, on the other hand, by the process which in one 

 word may be termed "education." The theory of an origin- 

 ally depraved nature, which leaves no room for possible 

 good in man's mental constitution, in this view, has no 

 logical standing whatever; since it begins by postulating 

 the grossly materialistic view that all human qualities and 

 mental acts are vile. Bad and depraved by nature, sodden 

 with " original," that is, " natural sin," we may hopelessly 

 inquire, " Why fight against nature, and why try to alter the 

 fiat of the inevitable ? " More cheering, because more true, 

 is the doctrine which the genesis of nerves impresses upon 

 us, namely, that from our ancestors we receive a natural 

 heritage in which good and evil certainly commingle ; but 

 which is also susceptible, through the effects of new habits 

 and proper training, of repressing the baser parts of our 

 nature, and of evolving in our lives the "outward and visible 

 sign of an inward and spiritual grace." 



