Saturday, April 12, 2008

Thought Experiments and Begging Questions

Adam Rawlings has an interesting post complaining that common philosophical thought experiments are "hopelessly question-begging":
The zombie scenario just assumes, without argument, that a fully-specified physical world contains no consciousness. The amoralist case just assumes, without argument, that full knowledge of morality will not give sufficient motivation to act. The Frankfurt-style examples just assume, without argument, that being under the control of a counterfactual demon is still a case of genuinely free choice in action. And the direction of fit metaphor just assumes, without argument, that these two directions of fit must both exist. In other words, the cases are structured in such a way as to appeal solely to intuitions favourable to one side of a philosophical dispute, bypassing the inconvenient "giving an argument" stage completely.

All very true, I grant, but there's nothing wrong with this. To see why, suppose I were to claim that 'bachelor' is defined to mean 'unmarried man'. You might respond with putative counterexamples, e.g. pointing out that the Pope is an unmarried man, but (intuitively) not a bachelor. It would be odd for me to complain, "You're just assuming, without argument, that the Pope is not a bachelor!" True, you say, but I'm missing the point. You merely wanted to draw my attention to a possibility that I may have neglected. Do I really deny that the Pope is no bachelor, you ask? If so, we must look elsewhere to resolve our disagreement. But it was not unreasonable for you to offer the suggestion that you did: you had every reason to expect that it might inform my view, even though I did not antecedently agree with your conclusion that there could be unmarried men who aren't bachelors.

Compare Stalnaker's wonderful insight:
With riddles and puzzles as well as with many more serious intellectual problems, often all one needs to see that a certain solution is correct is to think of it--to see it as one of the possibilities.

Sometimes a vivid illustration is all we need to advance our understanding, and so make philosophical progress.

With this in mind, I think it helps to understand 'begging the question' in dialogical (rather than purely logical) terms. Every valid argument contains its conclusion in its premises, after all. So that alone can't be grounds for complaint -- there's nothing wrong with drawing out implicit commitments which one hadn't previously appreciated. Rather, what's problematic is if an argument is not going to be rationally persuasive to anyone who doesn't already accept the conclusion. Fruitful debate merely calls for arguments that are dialectically effective for logically non-omniscient agents such as ourselves. Some arguments aren't going to help advance the dialectic at all, so it's those which I would call 'question begging'.

The thought experiments Adam discusses aren't like that though. Many people are persuaded upon learning of zombies and Frankfurt cases. These thought experiments make vivid to us certain conceptual interrelations which we had not fully appreciated beforehand. That said, further argument will be required if someone sincerely disputes the proffered description of the scenario in question (as Adam suggests). But that merely shows that these thought experiments are not guaranteed to be dialectically effective. That's fine; there's plenty of space between 'knock down' and 'mistaken' for these arguments to occupy.


  1. Riposte!

    Oh, and I'm trying to get "bright purple porpoise" started as a whole philosophical term of art. Pass it on!

  2. I suspect that opponents of these sorts of experiments have something else in mind: that if you don't agree with the intuition to start with, then the extra baggage of a thought experiment built upon it should not rationally convince you otherwise (of course it might convince your non-rationally; or it might convince you if you didn't already have an intuition to start with). Thus the objection is that thought experiments involve a sophistic, non-rational form of manipulation.

    And the histories of thought experiments really get this point across, I think. If you look at Frankfurt cases, for example, there have been a few decades of back and forth on them, consisting mainly of both sides restating their intuitions in more and more complex (and sometimes more and more implausible) garb. But the disagreement is still the same, and there is never any progress toward a resolution. Fischer and Ravizza's use of Frankfurt examples is exactly as problematic as Frankfurt's, if not more so, and the standard response is exactly the same as the response to Frankfurt was.

    So there is another level to the criticism: that focus on thought experiments creates a build-up of literature that brings us no closer to solving any philosophical problems and really doesn't help to get us clearer on them. Given the standard pressure to publish, it should be no surprise that most of what is published would be devoted to pointless discussion of the same points over and over with regard to the same intuitions with a pretense at novelty. But surely we need not glorify this use of paper.

  3. If the 'thought experiment' is a genuine contribution to the dialectic, it should be possible to state the argument they encapsulate in a more abstract form that allows you to see that the argument carries through without having to advert to the thought experiment itself, and without any philosophical sleight of hand with the words or images -- that it is the rational structure of the thought experiment, not the imaginative features of it, that are doing the real work. (Good scientific thought experiments can be confirmed by such abstraction and generalization.) I'm very sure that Frankfurt examples, for instance, are not easily susceptible to this sort of confirmation; indeed, I think Frankfurt examples can easily enough to be shown to be just muddled, and structurally incapable of making the point they are usually said to be making, and so not capable of such confirmation at all. And I think this could be said generally for thought experiments in philosophy of mind.

  4. I posted on some thoughts on the issue. Frankfurt counterexamples make no sense to me -- Frankfurt presumes compatibilism, ignoring all of the obvious problems with it. He says that he's shown that one can have no alternate possibilities and be morally responsible, but what matters in the free will debate is alternate choices -- and he hasn't shown that you can have no alternate choices and be morally responsible.

    As far as what you're saying: the trouble is that these thought experiments can never be empirically validated, and thus they never really do anything when they get metaphysical. The zombie one is particularly dubious to the point where it should be immediately discarded.

    Look at another example: Searle's Chinese Room. This is really just a tailored intuition-pump that Searle uses to get gullible people to think like he does. His experiment constructs such as a naive, crude computer program that it's essentially a strawman argument. I can easily imagine algorithmns which create a sense of self-consciousness and synthesize various bits of information into new innovations.

    I think philosophers need to realize that metaphysics is done. Philosophy is the study of ideas, not reality. But maybe I'm wrong. I'd like to see some good metaphysical thought experiments. In the meantime, it's sad (and surprising) that such crude ones dominate modern philosophy.


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