Sellars often described his realistic naturalism as ‘nominalistic,’ but the point is not so much to deny that there are abstracta as to tell us what language that uses abstract singular terms is doing for us and how differently it functions from language using concrete singular terms. If we understand how abstract singular terms function, the claims of the Platonist metaphysician seem an elaborate (and perhaps misleading) way to make a simpler, more pragmatic point.  First, Sellars argues that the then-prevalent standard of ontological commitment —being the value of a variable of quantification— is mistaken (GE, NAO).  Such a criterion makes the indeterminate reference of quantified variables more primitive than any form of determinate reference. This is incompatible with Sellars’s understanding of naturalism, and he claims it also gets the grammar of existence claims wrong.  (Sellars construes quantification substitutionally; see Lance 1996.)  Sellars proposes a different standard: we are committed to the kinds of things we can explicitly name and classify in the ground-level, empirical, object-language statements we take to be true.