Truly … as accidental as my Life may be, or as that random Humour is, which governs it; I know nothing, after all, so real or substantial as My-Self. Therefore if there be that Thing you call a Substance, I take for granted I am one. But for anything further relating to this Question, you know my Sceptick Principles: I determine neither way.
Vol. 2, p. 83; Part 3, Sect. 1 "Philocles to Palemon". - Characteristicks of Men, Manners, Opinions, Times (1711)