Abstract
The Socratic Paradox (that only Socrates is wise, and only because only he recognizes our lack of wisdom) is explained, elaborated and defended. His philosophical scepticism is distinguished from others (Pyrrhonian, Cartesian, Humean, Kripkean Wittgenstein, etc.): the doubt concerns our understanding of our beliefs, not our justification for them; the doubt is a posteriori and inductive, not a priori. Post-Socratic philosophy confirms this scepticism: contra-Descartes, our ideas are not transparent to us; contra-Verificationism, no criterion distinguishes sense from nonsense. The import of this scepticism for professional ethicists is examined.