37<3 STUDIES OF NATURE. 



extolled, and dignified with the title of axiom* 

 But, if Tarn not miftaken, this argument labours 

 under an efTential defect, in that it has not the 

 generality of a fundamental principle ; for it im- 

 plicitly follows, that when a man does not think, 

 he ceafes to exift, or, at leaft, to have a proof of 

 his exiflence. It follows farther, that the animal 

 creation, to which Defcarles denied the power of 

 thought, had no proof that they exifted ; and that 

 the greateft part of beings are in a flate of non- 

 existence with refpect to us, in as much as they 

 excite in us fimple fenfations merely, of forms, of 

 colours, and of movements, without any reference 

 to thought. Befides, the refults of human thought 

 having been frequently employed, from their ver- 

 fatility, to fuggeft doubts refpe&ing the exiftence 

 of God, and even of our own, as was the cafe with 

 the fceptic Pyrrho ; this reafoning, like all the ope- 

 rations of the human underftanding, falls under 

 well-grounded fufpicion. 



I fubftitute, therefore, in place of the argument 

 of Defcartes, that which follows, as it appears to 

 me both more fimple and more general : / feel, 

 therefore I exift. It extends to all our phyfical fen- 

 fations, which admonifli us much more frequently 

 of our exiftence than thought does. It has for it's 

 moving principle an unknown faculty of the foul, 

 which I call fentiment, or mental feeling, to which 



thought 



