Saturday, October 04, 2008

Does Skepticism have Practical Import?

A fairly common sentiment among my intro M&E students seems to be that the radical skeptic wins on the philosophical merits, but it doesn't really matter anyway -- it doesn't change what we should do in practice. Here are a couple of ways of challenging this assumption.

(1) Some (e.g. altruistic) actions are only worth taking because of their expected effect on others. If it turns out that you're a BIV (Brain in a Vat), and the rest of us mere figments of your imagination, then you'd do better to ignore the imaginary problems of starvation and disease, and simply aim at maximizing your own pleasure. If you are agnostic between the various possibilities, then presumably you should compromise in your behaviour too: donate to Oxfam occasionally, just in case, but also be a bit more hedonistic and self-absorbed than you would be if you were certain that the rest of us really existed too. This seems a pretty important practical difference.

(2) Further, what practical risks it is reasonable to take depends upon what probabilities it's reasonable to believe. You should only accept a bet, for example, if the payoff:cost ratio is better than the odds of losing -- i.e. if the expected value of the bet is positive. An essential part of that calculation is judging how likely you are to win or lose. If the inductive skeptic is right, and you have no reasonable grounds for making such a judgment about the future, then this may imply that ordinary betting behaviour is unreasonable too.

[My previous post discusses some more general links between theoretical and practical reason.]

A subtly different line of thought grants that we can't refute the skeptic, but suggests that we might as well assume they're wrong, and so carry on ordinarily. (Note the difference: the previous suggestion assumed that the skeptic was right, and sought to ignore them nonetheless. If we assume the skeptic is wrong, we avoid the above problems.) The key move here is what I call a 'practical' transcendental argument: anti-skepticism is a precondition for successful inquiry, so we may as well take it on faith. If we're wrong, we're screwed anyway; but if we're right -- if we have any chance at all of attaining knowledge -- then this assumption positions us to make the most of it.


  1. You might as well take it on faith that the skeptic is wrong... but even when you do, how does that help you with bets? Suppose I'm the following sort of anti-skeptic: I think all statement tokened by Big Brother are true. But the mere wrongness of skepticism doesn't vindicate my particular belief system, nor any other. If we want to make rational bets, we must rationally prefer one dogmatic system over another, for non-circular reasons. And this is the real difficulty that skepticism presents for us. The Problem of the Criterion is just hard. It's not enough for a dogmatist to beat back the "ideology" of skepticism; they must beat back every competing dogmatism. Either they do that, or the dramatically relativize their account of rational betting to make space for all the different "leaps of faith" that non-skeptics take as their epistemic foundation.

  2. "If we want to make rational bets, we must rationally prefer one dogmatic system over another, for non-circular reasons."

    We need to be careful here; demands for non-circularity may be impossible to fulfill, in which case an anti-skeptic will not accept any such burden.

    Now, one claim in my post above was simply that rational betting requires rational belief. You can't have the former without the latter. I'm not here making any positive claims about what rational belief consists in (though that's surely an important question). For now I'm simply pointing out that we'd better think we have rational beliefs if we think our practical behaviour is rational. You can't endorse everyday betting behaviour if you accept the skeptic's arguments. So rejecting skepticism is the first step.

    Now, you raise an important point that "the mere wrongness of skepticism doesn't vindicate my particular belief system, nor any other." There's certainly a lot of work left to do even after we reject skepticism. But that's work for another blog post, another day.

  3. Actually, I think radical skepticism would have more severe practical consequences than just that! Indeed, I think one would be very accident-prone, for one thing. "I have no reason to believe that that tree is actually there. I might as well drive through it!" Personally, I think that no matter what one rationally decides to think about skepticism, it's psychologically impossible to be a radical skeptic in practice.

    People have tried though. The ancient skeptics, for instance, actually took skeptical theses to heart, and tried to live their lives as if they really didn't know anything! I heard an anecdote about one ancient skeptic who one time almost walked right off a cliff. Fortunately his students realized what he was up to and managed to stop him -- the skeptic maintained that he had no reason to think the cliff was real. (Personally I think he only dared to do his little stunt because he knew his students would prevent him.)

  4. Lvb, it's a common misconception that the Pyrrhonean skeptics would reason in the way you suggest. Their practical actions were focused on "living normally" - according to their traditions, upbringing and training. Pyrrho himself was a competent and beloved general who lived to an old age.

    One may suspect that Pyrrhoneans didn't fully live by their principles, but I've recently started thinking that maybe they did. Their focus was on ceasing to seek reasons and justifications for their actions, and to whatever *appears* right without any illusion that they have a reason for thinking that it is right. Ancient skepticism was about refusing to seek rationalizations for action and "just" acting.

    When we consider the difficulty of coming up with an account of rational action, it's amazing that we don't starve to death! (That was a joke, of course: We don't wait to discover which action is rational before we act; we just act. But we think we *ought to* act with reason and justification. So it's we dogmatists who can't live by our principles. The Skeptics have it easier.)

  5. I like the "practical transcendental argument," (thought of it independently) but it only goes so far in refuting hard skepticism. Solipsism, as I see it, cannot be rejected through such an argument, since if the external world does not exist, then you can still form rational beliefs about your own self and live your lonely Solipsistic life fruitfully. Although the practical transcendental argument does cut down to size an awful lot of skepticism. (Skepticism over time, or the validity of deductive reasoning for instance.) Also, I think that if you grant what pragmatic transcendentalism requires you to grant, then you have enough room for a solipsist to be able to figure that the "external world hypothesis" is as good a model as any for describing their life even if they can't be sure it's true.

    And regarding the pragmatic questions, I'm somewhat inclined to believe that hedonistic egoism is "rational" for the very reason that solipsism might be true, although I tend to waffle for the usual reason of thinking that egoism justifies quasi-altruistic behavior.

  6. David, I believe it. I've never studied ancient skepticism myself; all I know, I know from my professors -- and the truth is they probably haven't studied ancient skepticism either. Besides, your account of the Pyrrhoneans makes them sound much more reasonable, so I'm inclined to think it's correct on that basis alone.


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