What Makes a Good Skeptical Thought Experiment?

How do skeptical thought experiments work? The skeptic invites us to “entertain” a vividly described possibility, then argues that skeptical conclusions follow from our inability to rule that possibility out. I contend that the argument’s soundness hinges on whether the skeptical possibilities generate legitimate doubts: we need to separate the issue of whether we can rule a possibility out from whether we have to rule it out. I canvass a number of familiar interpretations of “possible,” including logical, a priori, and epistemic possibility, and argue that it is much harder than is generally acknowledged for a skeptical possibility to raise legitimate doubt. The first time you read Descartes’ Meditations, or watch The Matrix, skeptical worries naturally flourish. You worry that you may not know the ordinary things you took yourself to know. How do skeptical thought experiments work? At first blush the procedure seems simple enough. The skeptic asks us to entertain a vividly described scenario and invites us to “feel the force” of the skeptical hypothesis. Can’t we just see that the possibility raises doubt about our claim to know that things are as they seem, that we need to “rule out” the scenario in order to know? sdf It would be great if we could rule out all skeptical scenarios. But even if we cannot, the fact that we cannot by itself does not show that we have to rule them out. It would be great if I could dunk a basketball; the fact that I cannot does nothing to establish that I have to do it. Dunking a basketball is something I don’t have to do, that I can’t do, and that I nonetheless would like to be able to do. Maybe something similar is true for ruling out skeptical possibilities. It might be something that we’d like to be able to do, that we can’t do, but unless the possibilities raise legitimate doubt, it isn’t something that we have to do. PAPER #4 Paper #1