Mooreanism conjoins at least two claims: that (i) normative properties are grounded in natural properties, and that (ii) normative properties aren’t defined by natural properties; normative properties are instead sui generis. Call (i) the _grounding claim_ and (ii) the _non-definitional claim_. I argue that Mooreanism faces a problem when formulated in the terms of contemporary postmodal metaphysics. Namely, under recent theories of grounding and real definition, the grounding and the non-definitional claims may be inconsistent with each other. This is a (...) problem, because Mooreanism is an important option for the normative non-naturalist. If Mooreanism were inconsistent, then only stronger forms of non-naturalism—including those positing no grounding relations between the natural and the normative—would be available. After rejecting a variety of other proposals for addressing the problem, I argue the problem can be resolved through a recently drawn distinction in the metaphysics of ground between constitutive and non-constitutive grounding. In addition to precisifying Mooreanism, I argue that the distinction between constitutive and non-constitutive grounding reveals space for further varieties of both non-naturalism and naturalism. (shrink)