Full Idea
Who defines the healthy man, or who is awake or asleep? This is a pursuit of foundations, but this is seeking an account where there isn't one. The starting point of a proof is not a proof.
Gist of Idea
The starting point of a proof is not a proof
Source
Aristotle (Metaphysics [c.324 BCE], 1011a10)
Book Reference
Aristotle: 'Metaphysics', ed/tr. Lawson-Tancred,Hugh [Penguin 1998], p.104
A Reaction
a comment on Descartes