Page:A Letter to Adam Smith on the Life, Death, and Philosophy of his friend David Hume (1777).djvu/56

 is to give us a doubtful solution of doubtful doubts.

That the human understanding, acting alone, does entirely subvert itself, and prove by argument, that by argument nothing can be proved.

That man, in all his perceptions, actions, and volitions, is a mere passive machine, and has no separate existence of his own, being entirely made up of other things, of the existence of which he is by no means certain; and yet, that the nature of all things