This dimension of Socrates' thought has been, of course, highly influential with skeptics. Indeed, it was in part on the basis of this sort of gesture in Plato's works that the Academic skeptics regarded themselves as inheritors of Platonic philosophy. Later the idea became known as "learned ignorance," for example in Nicholas of Cusa's work by the same name. It's an interesting thing to examine the different ways philosophers have tried to cope with the constellation of ideas involved with coming to understand one's ignorance, as well as other dimensions of human finitude. Hellenistic and Greco-Roman skeptics explored the ways in which doubt my characterize humanity's relationship to knowlegdge and whether skeptical arguments advance any positive wisdom or simply tear things down. Montaigne formulated the now-classic, "What do I know?" Erasmus called himself a "foolospher." Hume explored concepts of "natural," "common," ordinary, and non-dogmatic forms of belief while still acknowledging skeptical...

May I weigh in a bit? I think that panelists are right to suggest that while the dream argument addresses the veracity of perception about the world, the demon argument goes farther and addresses mathematical and logical inferences. I'd like, however, to return to Peter Lipton's question about why the cogito survives the demon argument. There's a bit more to say on that score that explains Descartes's position. There's a difference between mathematical and logical inferences and the cogito, and that is that what Descartes finds persuasive about the cogito is not a matter of inference but rather direct intuition. The demon argument works but pointing out that in any discursive movement of thought, from one idea to another, the demon might interfere. Discursive thought, therefore, is dubious. N.B. that's why the example Alexander George quotes is about discursive movements like "adding" and "counting." In this way, Descartes anticipates, in a way, the point Quine makes in his article, "Two...