 One important application of ontological dependence is the analysis of the notion of “substance”—a basic or fundamental entity which possesses at least some degree of ontological independence (for discussion on the various uses of “substance” in philosophy, see the separate entry on  substance).  If the idea of ontological independence is somehow associated with “substance”, then it seems that some account of what the relevant dependence amounts to will be required. In fact, those familiar with Lowe 2005 [2010] (an earlier version of the present entry), will recall that the discussion was entirely focused on finding the most plausible account of ontological dependence for the purposes of analyzing the notion of substance (this discussion originates from Lowe 1998: Ch. 6). This also ties in with a more general application of ontological dependence, namely, the study of formal ontological relations obtaining between ontological categories, of which substance is a prime example (see also Hoffman &amp; Rosenkrantz 1994, Schaffer 2009, and Nolan 2011). So how should we define “substance” given the various notions of ontological dependence that we have at our disposal? It will be recalled that one particularly powerful notion of ontological dependence is the notion of identity-dependence, which we arrived at when looking for an asymmetrical—or, at least, an antisymmetrical—relationship of ontological dependence. It seems that if substances are considered as ontologically independent entities, then an asymmetric relation is required. One possibility for defining substance, which relies on  (EDR)  is the following: