OF HEALTH AND HUMAN NATURE. 35 



SECT. VI. 



OF HEALTH AND HUMAN NATURE. 



74. Since health* which is the object of physiology, 

 depends upon such an harmony and equilibrium of the 

 matter and powers of the system, as is requisite for the 

 due performance of its functions, it is very evident how 

 the four principles, examined above, contribute to its 

 support. 



75. Fluids properly prepared are the first requisite ; 

 in the next place, solids duly formed from the fluids; 

 then the invigorating influence of the vital powers; lastly, 

 a sound mind in this sound body. 



76. These four principles act and react perpetually 

 upon each other : the fluids are stimuli to the solids ; 

 these again are calculated by their vital powers to ex- 

 perience the influence of these stimuli, and react upon 

 them. In reference to the intimate union of the mind 

 with the body, suffice it at present to remark, that it is 

 far more extensive than might at first be imagined. For 

 instance, the influence of the will is not confined within 

 the narrow limits of those actions designated voluntary 

 in the schools of physiology ; and the mind, on the 

 other hand, is influenced by the affections of the body, in 

 many other ways than by the perceptions of sense.f 



* Theod. G. Aug. Roose, Uber die Krankheiten der Gesunden. Gutting-. 

 1801. 8vo. 



G. Chr. Klctt, Tentamen evolvendi notionem de sanitate hominis. Wirceb. 

 1794. 8vo. 



•f Galen, quod animi mores corporis temperaturas sequantur. 



D 2 St. 



