LETTERS TO BROTHER JOHN. 107 



degree of SENSIBILITY becomes an infallible test of 

 the state of the health. 



I have already proved that it is the SENSIBILITY 

 of our organs which establishes the necessary rela- 

 tion between ourselves and the objects which sur- 

 round us. From this it follows directly, that it is 

 upon SENSIBILITY that all our pleasures and all ou r 

 pains depend: for there is no pleasure and no 

 pain which is not derived to us from impressions 

 made by external objects upon our feeling of 

 which feeling, SENSIBILITY is the soul. I mean, 

 the feeling as well of the mind as the body. 



Now, the SENSIBILITY of a perfectly healthy man 

 is so regulated, as to afford him the greatest possible 

 degree of pleasure with the least possible degree of 

 pain ; that is, consistently with his terrestrial exis- 

 tence. Indeed, our pleasures are the voluntary and 

 bountiful gift of nature. For our pains, we have 

 nobody to thank but our foolish selves. So good 

 has the great Governor of the Universe been to us, 

 that we could not, if we would, escape pleasure; 

 but, in almost every instance, we can avoid pain, if 

 we will : for pain is only a warning voice, intima- 

 ting to us that we have got into a false position 

 that we are doing something which we ought not 

 to do, or leaving something undone which we ought 



