PHL100Y1 Lecture Notes - Lecture 5: Modus Ponens, Philosophical Skepticism, Contraposition
Document Summary
[(1) and definition of evidential certainty ] (p2) knowledge requires evidential certainty: for any proposition about the external world. P, one knows p only if one is evidentially certain of p. (c2) therefore, we do not know any propositions about the external world. As we noted last week, one might reply to this argument in at least two ways: (i) one might challenge. P1 and insist that at least sometimes our evidence does guarantee. Or (ii) one might challenge p2 and insist that knowledge does not require evidential (or any kind of) certainty. (we"ll discuss this move when we talk about vogel"s article. ) Moore discusses another kind of skeptical argument, one which doesn"t seem to have anything to do with evidential certainty. Though we could formulate it in terms of various skeptical hypotheses, let us, in keeping with moore, use the dreaming hypothesis: Since this argument generalizes, it can be turned into a powerful argument for skepticism.
