According to the simplest form of reliabilism, knowledge is reliably formed true belief. This formulation of the view is subject to a Gettier-style problem, in that one could reliably form true beliefs in a lucky way. One way around this problem is to restrict the kinds of reliable processes that are relevant to whether or not an agent has knowledge, such that one must gain one’s true belief via one’s epistemic virtues or cognitive faculties. Such a view is called virtue epistemology. A different problem facing reliabilism, even in this modified form, is that it allows knowledge in some controversial cases where agents have no good reason for thinking that they are reliable. While epistemic internalists insist that knowers must always be in possession of supporting grounds for their beliefs, epistemic externalists allow that sometimes one might have knowledge even while lacking such grounds. Reliabilists, and those virtue epistemologists who regard their view as a variant on reliabilism, thus tend to be epistemic externalists. Since employing an epistemic virtue, unlike employing a cognitive faculty, tends to always result in an agent having supporting grounds for her beliefs, one way of advancing a virtue epistemology which is allied to epistemic internalism is to insist that the employment of an epistemic virtue is essential to gaining knowledge.