Jonathan L. Kvanvig

The knowability paradox derives from a proof by Frederic Fitch in 1963. The proof purportedly shows that if all truths are knowable, it follows that all truths are known. Antirealists, wed as they are to the idea that truth is epistemic, feel threatened by the proof. For what better way to express the epistemic character of truth than to insist that all truths are knowable? Yet, if that insistence logically compels similar assent to some omniscience claim, antirealism is in jeopardy. Response to the paradox has drifted toward a common theme, a theme I will argue is a non-starter in resolving the paradox. Seeing this point will also make clear the philosophical inadequacy of simply viewing the paradox as a refutation of a wide range of antirealisms.

Duncan Pritchard’s book (Epistemic Luck, Oxford University Press, 2005) concerns the interplay between two disturbing kinds of epistemic luck, termed “reflective” and “veritic,” and two types of arguments for skepticism, one based on a closure principle for knowledge and the other on an underdetermination thesis about the quality of our evidence for the everyday propositions we believe. Pritchard defends the view that a safety-based account of knowledge can answer the closure argument and provide an account of how veritic epistemic luck is eliminated. He also argues that reflective epistemic luck cannot be eliminated, and that even though it is the sort of luck with which the underdetermination argument is concerned, the fact that this type of luck cannot be eliminated doesn’t undermine knowledge. Instead, it undermines the assertibility of our knowledge, at least in skeptical contexts. So when the skeptic challenges the idea that we know using the underdetermination principle, we have no legitimate response to offer, and it is this fundamental fact of epistemic life that Pritchard terms our inevitable epistemic angst.

A dispute in epistemology has arisen over whether some class of things epistemic (things known or justified, for example) is closed under some operation involving the notion of what follows deductively from members of this class. Very few philosophers these days believe that if you know that p, and p entails q, then you know that q. But many philosophers think that something weaker holds, for instance that if you know that p, and p entails q, then you are in a position to know that p, or if you know that p and you competently deduce p from q, then you know that q. However there are some considerations tracing back to Wittgenstein’s On Certainty and some early work by Fred Dretske that suggests even these weaker principles are false.

One response to the preface paradox—the paradox that arises when each claim in a book is justified for the author and yet in the preface the author avers that errors remain—counsels against the preface belief. It is this line of thought that poses a problem for any view that places a high value on intellectual humility. If we become suspicious of preface beliefs, it will be a challenge to explain how expressions of fallibility and intellectual humility are appropriate, whether voiced verbally or encoded mentally. Moreover, banning expressions of intellectual humility is especially disturbing in our context, for such a preface claim is just the sort of expression of intellectual humility that is supposed to provide a barrier to the costly damage that can be done by zealous faith found in various forms of fundamentalism. The goal is thus to find a way to express humility without engendering paradox.

Mona Simion questions whether there is a distinction between taking back an assertion and taking back only the content of an assertion, as I have claimed. After arguing against the distinction in question, Simion grants that there is a difference between the cases that I use to illustrate the distinction, and thus turns to the task of explaining the difference in a way that keeps it from undermining the knowledge norm. The explanation she offers is in terms of a distinction between doing something that is wrong and doing something that is blameworthy. I respond here by defending the distinction and questioning the explanation she gives of it.