Is understanding epistemic in nature? Does a correct account of what constitutes understanding of a concept mention epistemological notions such as knowledge, justification or epistemic rationality? We defend the view that understanding is epistemic in nature – we defend epistemological conceptions of understanding. We focus our discussion with a critical evaluation of Tim Williamson’s challenges to epistemological conceptions of understanding in The Philosophy of Philosophy. Against Williamson, we distinguish three kinds of epistemological conceptions and argue that Williamson’s arguments succeed against only the most heavily committed kind, and leave the less heavily committed kinds untouched. Further, we argue that Williamson’s elaboration of lessons from his arguments point in a direction opposite of his own conclusions and give vivid articulation and support to epistemological conceptions. We suggest also that skepticism about Williamson’s larger metaphilosophical conclusions – according to which understanding plays no special role in the epistemology of philosophy – may be in order.