Suppose you’ve read Bill Alston’s illuminating piece on levels confusions in epistemology, and agree that the skeptic can’t win the argument by going up a level. That is, where the argument is about a claim to know that p, the skeptic is entitled to ask about one’s basis for p–that’s fair game. But when the answer is that e is one’s evidence for p, you can’t undermine the claim to knowledge by insisting that the person defend that e is evidence for p. That is, it is not a requirement for knowing that p on the basis of e that one knows that e is good evidence for p, or that one can defend the claim that e is good evidence for p, etc. That’s to be guilty of a levels confusion.
Then turn to Pollock on defeaters. According to John, there are two basic kinds, rebutting and undercutting defeaters. Rebutting defeaters are evidence against p, where the belief that p is the belief to be evaluated. Undercutting defeaters, however, are reasons for thinking that the basis of the belief, e, is not a truth indicator of p.
This characterization takes a metalevel claim to be relevant to the object level issue of which beliefs are justified. So, for those convinced by the Alston piece, there is some tension.
For those of us who find John’s position pretty compelling, we now have to say that the argument against skepticism provided by Alston is no longer decisive. All we could claim, if we still find something useful in Alston’s arguments, is that sometimes a levels jump is not relevant to the question of whether one knows or is justified–not that it never is. So to respond to the skeptical challenge of the reasons we have for thinking that our evidence is really truth-indicating, we can only say that it is not obvious that we need such a defense in order to know.
We are left, then, with the following. If we had a defense of the truth indicator claim, the skeptic’s challenge would be met. If the skeptic had a defense that the evidence wasn’t truth-indicating, the skeptic would win in virtue of being able to present us with an undercutting defeater. In the normal case, however, we are stuck between these two positions. Alston’s arguments make us wary of levels confusions, but we are not willing to deny the force of undercutting defeaters. What would be nice is to be in either one of the following positions: either we have good reason to believe that our evidence is truth indicating, or the skeptic can provide good reason that our evidence is not truth indicating.
Instead, we are normally in the following position. When we have reason to think the truth-indicator claim false, we have an undercutting defeater. But in the normal case, we have no reason either way. So it looks like the appropriate epistemic attitude to take is that of withholding: we shouldn’t believe that our evidence is truth-indicating and we shouldn’t believe that it isn’t.
I hope that strikes you as an uncomfortable position. I’m inclined to think it needs to be avoided; that we need an account of justification so that if you’re justified in believing a claim, you have good reason to think that your evidence is truth-indicating. If that’s right, however, then we need a broader conception of undercutting defeaters: not only claims that give reason to think our evidence is not truth indicating count, but so do claims that render withholding the proper attitude to take toward whether our evidence is truth-indicating.
This inclination is troubling in itself, however, for notice that such a characterization of undercutting defeaters jumps another level: if rebutters are object-level defeaters, and Pollock’s undercutters are second-level defeaters, the new account would make room for third-level defeaters. And once we’ve gone this far, it’s pretty easy to see how to motivate a fourth-level account as well, and so on (you just have to remind yourself of the discomfort of having reasons to withhold at any particular level). Can the concept of defeat really be that complicated?