LETTERS TO BROTHER JOHN. 179 



no one but the infidel proselyte to the doctrines of 

 blind chance could reconcile it either to his reason 

 or his conscience to believe it. 



But that disease and premature death formed no 

 part of the original design of man, is superabun- 

 dantly proved by the innumerable contrivances 

 which nature has instituted, in every part of the 

 machine, to repel them ; and the mighty efforts 

 which she makes, under disease, to escape them. 



My inference, then, is this; that the vital actions 

 constitute a system of nature, which is, like her 

 other systems, per feet in itself; that, as the planetary 

 system depends for its health (that is, the due per- 

 formance of its functions) on the law of gravitation, 

 so the health of the vital actions depends on man's 

 conduct, with relation to the manner of his nutrica- 

 tion and mode of existence ; and that, as the plane- 

 tary system is incapable of derangement while the 

 law of gravitation remains unchanged, so neither is 

 the system of man capable of disorder, otherwise 

 than by some misconduct., in his manner of feeding, 

 and his habits of life. Beyond the influence which 

 results from our conduct in these two respects, we 

 possess no more controul over the motions consti- 

 tuting health, than we do over those of the heavenly 

 bodies ; every thing being effected by the inherent 



