 A second way to see that supervenience is not identical to either grounding or ontological dependence is to note that the latter two relations are widely (though not universally) thought to be irreflexive and asymmetrical. Nothing can ground or ontologically depend upon itself, and nothing can ground or ontologically depend on something that also grounds or depends on it. But as we have seen, supervenience is reflexive and not asymmetrical (see  Section 3.2).  (For challenges to the claim that dependence and/or grounding are irreflexive and asymmetric, see Jenkins 2011, Bliss 2014, Wilson 2014, and Barnes forthcoming; for a reply to these challenges, see Bennett 2017, sect. 3.2). 