LETTERS TO BROTHER JOHN. 83 



raena are to the centrifugal and centripetal forces, 

 and the antagonization of these forces by each 

 other what the motion of the hands of a watch is 

 to the main-spring and its elasticity ; viz. the sum 

 total of numerous effects, of which these four 

 attributes of organic matter above mentioned are 

 the secondary causes. These effects we call living 

 actions actions, the totality of which constitutes 

 life. 



Organized matter is a harp, of which vitality is 

 the musical power : stimuli are the fingers of the 

 performer : and life is the music produced a hymn, 

 day and night, in praise of the goodness and power 

 of HIM, who permits 



" This harp of a thousand strings 

 To keep in tune so long." 



Such is life. Now, what is health ? 



As life consists in the aggregate union of all 

 the living actions, and indifferently, whether those 

 actions be well or ill performed ; so health consists 

 in the aggregate union of such only of those actions 

 by which nutrition is carried on and not indiffe- 

 rently, whether they be well or ill performed ; but 

 exclusively, when they are well performed. And 

 disease consists, exclusively, in their being (one or 

 more of them) ill performed. 



