LETTERS TO BROTHER JOHN. 173 



the same laws of nutrition ; and these laws are also 

 liable to be modified by the conduct and habits of 

 these animals : but, then, the conduct and habits of 

 brutes are themselves dependent on instinct which 

 is unerring ; whereas the conduct and habits of man 

 depend on his own caprice the use or abuse of 

 his reason, which is not unerring 1 . 



The grand distinction, therefore, between all the 

 other systems of nature and that of man seems to 

 be, that while the former are sustained by unerring 

 laws, the latter is supported by laws which are 

 subservient to the erring conduct of man, with 

 relation to the manner of his nutri cation* and 

 mode of existence. 



Now, it is to this " erring conduct, with relation 

 to the manner of his nutrication and mode of 

 existence," that I look, as the cause and source of 

 human disease. 



To every system nature has allotted a determinate 

 position ; and she has established a fixed relation 

 between each system, and all the other systems by 

 which each is surrounded ; and from their allotted 



* Be careful not to confound the term " nutrication" with 

 the term " nutrition." Nutrication signifies the supplying the 

 mouth with food : nutrition, the assimilation of that food to 

 our own structure. 



