LETTERS TO BROTHER JOHN. 305 



strength ; and that vigorous contractility is incom- 

 patible with a high degree of sensibility. 



No one, I think, will venture to deny, that culti- 

 vation and refinement have the direct effect of 

 heightening man's sensibility. The very word 

 " refinement " seems necessarily to imply a superior 

 degree of sensibility. One can hardly conceive a 

 high degree of refinement unaccompanied by a high 

 degree of sensibility also ; for the very meaning of 

 the term " refinement " seems to be a condition 

 from which every thing calculated to offend a deli- 

 cate sensibility is removed. 



Besides, one of the first effects of civilization is, 

 to substitute the labour of the brain for the labour 

 of the hands and feet. But the labour of the hands 

 and feet exercise is necessary to the existence of 

 a vigorous circulation and an energetic contracti- 

 lity; which are both incompatible with a high degree 

 of sensibility. Exercise, therefore, has the effect 

 of blunting the sensibilities : and, by a parity of 

 reasoning, a deficiency of exercise has the contrary 

 effect that of heightening the sensibility of man. 

 " This deficiency of exercise in the open air," says 

 Dr. James Johnson, " may be considered as the pa- 

 rent of one half of female disorders, by multiplying 

 and augmenting the susceptibilities to all external 



