This dissertation develops and defends a view of the relationship between knowledge and norms on action. The view I defend is an impurist one; on this view, whether a person knows that p can depend on factors that are unrelated to the truth or likelihood of p. On my impurism, normative facts about actions and options—including, for instance, the costs of relying on a belief in action—are among the non-truth-related factors that can make a difference to knowledge. My view is distinctive, in part, because of the further claim that moral facts about actions and options are among the normative considerations that can make a difference to knowledge. In a slogan: epistemic norms are sensitive to moral considerations. In an even shorter slogan: there is moral encroachment in epistemology. The first half of the dissertation defends the claim that there is moral encroachment in epistemology. In chapter 1 (“Pragmatic Encroachment and Moral Encroachment”), I argue that moral encroachment is at least as well-motivated as a more familiar view: the view that there is pragmatic encroachment in epistemology. In chapter 2 (“Uncertainty, Belief, and Ethical Weight”), I draw on insights from moral psychology to provide an original argument for moral encroachment. The second half of the dissertation starts from the assumption that there is moral encroachment in epistemology. It is devoted to describing in detail how moral encroachment works. In chapter 3 (“Moral Encroachment and Reasons of the Wrong Kind”), I distinguish between a radical and a moderate version of moral encroachment. I raise a problem for the radical version: it threatens to erase the distinction between epistemic and non-epistemic norms on belief. This problem, I note, does not afflict the moderate version of moral encroachment. In chapter 4 (“Knowledge and the Many Norms on Action”), I show that it is no trivial task to explain why knowledge is sensitive to both moral norms and norms of practical coherence. In (open full item for complete abstract)