The autonomy thesis is the claim that one cannot get a normative statement from purely descriptive statements. But despite its intuitive appeal a precise formulation of the thesis has remained elusive. In a recent paper, Maguire (2015) makes the promising suggestion that the thesis should be understood in terms of ground. But Maguire’s formulation, I argue, is based on controversial taxonomic assumptions that make the autonomy thesis into a non-substantive claim. I develop an alternative ground-based formulation of the autonomy thesis that appeals to the notion of normative relevance, which is in turn understood using the tools of truthmaker semantics. This formulation of the autonomy thesis avoids well-known counterexamples to other formulations and has significant advantages over Maguire’s formulation.