papers

I fully know that p if I know that p, I know that I know that p, I know that I know that I know that p, and so on ad infinitum. What, if anything, do I fully know? One response in the literature is that I fully know everything I know. This response is in tension with the plausible margin-for-error principle on knowledge. A different response in the literature is nothing: I don’t fully know anything. Recently, Goldstein (2024, forthcoming) defended a third view, according to which I fully know some things, but not everything that I know. This response is also in tension the margin-for-error principle. In this paper, I show that the possibility of full knowledge is consistent with the margin-for-error principle. We can have full knowledge even if the margin-for-error principle is true. I argue that the resulting picture of knowledge is well-motivated.

Two agents commonly know that p if they both know that p, they both know that they both know that p, they both know that they both that they both know that p, etc. Common knowledge can in principle arise in many kinds of situations. In this paper, I focus on two extreme kinds of cases: cases where agents can only reach common knowledge by communication, and cases where agents cannot communicate and still apparently have common knowledge. I examine three skeptical arguments to the conclusion that common knowledge is impossible in those cases, and argue that they fail because they make the Zeno Fallacy: the inference from the fact that something needs infinitely many steps to the conclusion that it is impossible to do.

This paper provides a defense of Parfit’s principle: when a person’s preferences are unknown, it is wrong to take, on their behalf, some of the risks that they could rationally choose to take. We argue that rejecting the principle leads to a false conclusion when deciding for more than one person. To do that, we prove a pair of theorems that show that all and only risk-seeking attitudes can lead to this result.