 An influential recent approach to the completeness question that is different from any we have considered so far focuses on the idea of grounding, something that has been extensively discussed recently in the metaphysics literature (see, e.g., Fine 2001, Schaffer 2009, Rosen 2010, Wilson 2014, Bennett 2017 and the essays in Correia and Schneider 2012). Intuitively, a property F is grounded in a property G just in case F holds in virtue of G, or the instantiation of G explains the instantiation of F. This suggests: 