Robust metanormative realists think that there are irreducibly normative, metaphysically heavy normative facts. One might wonder how we could be epistemically justified in believing that such facts exist. In this paper, I offer an answer to this question: one’s belief in the existence of robustly real normative facts is epistemically justified because so believing is indispensable to being a successful inquirer for creatures like us. The argument builds on Enoch's (2007, 2011) deliberative indispensability argument for Robust Realism but avoids relying (...) on an overly pragmatic account of the sources of basic epistemic justification. Instead, I suggest that the sources of basic epistemic justification are those belief-forming methods which are indispensable for zetetically indispensable projects, that is, projects which are constitutive of being a successful inquirer for embodied, agential creatures like ourselves. (shrink)