Ostrich nominalists often cite Quine’s criterion of ontological commitment in order to claim that their view is more parsimonious than rival positions in ontology such as realism. We show that Quine’s criterion, properly understood, does not support this claim. Indeed, we show that ostrich nominalism has a far more profligate ontology than realism.

In order to avoid the problems faced by standard realist analyses of the “relation” of instantiation, Baxter and, following him, Armstrong each analyze the instantiation of a universal by a particular in terms of their partial identity. I introduce two related conceptions of partial identity, one mereological and one non-mereological, both of which require at least one of the relata of the partial identity “relation” to be complex. I then introduce a second non-mereological conception of partial identity, which allows for (...) both relata to be simple. I take these three conceptions to exhaust the plausible ways of construing two entities as being partially identical. I then argue that there is no analysis (including those offered by Baxter and Armstrong) of a universal and a particular as being partially identical consistent with any of these three conceptions that (i) is coherent, (ii) is consistently realist, (iii) does not lead to absurd consequences, and (iv) offers a “solution” to the problem of instantiation that avoids the problems with the other standard realist responses. In so arguing, I offer a criticism of the analysis of instantiation as partial identity that is independent of the standard criticism that it entails the necessity of predication. (shrink)

Most theorists treat the ‘relation’ of identity as being more fundamental (or basic) than the ‘relation’ of (numerical) difference. Herbert Hochberg suggests, instead, that difference is to be treated as basic. My goal in this paper is to answer two related questions. First, what is it for a theorist to treat difference or identity as basic? Second, which of these two ‘relations’ is to be treated as basic? I begin by outlining four reasons that one might be motivated to endorse (...) the view that difference is to be treated as basic. Based on these reasons, I distinguish three ways of conceiving of what is involved in treating difference as basic: one conception involves the reification of the relation of difference, whereas the other two do not. Finally, I consider the theoretical consequences, particularly as concerns ontological parsimony, of treating difference as basic in these ways. My ultimate position is that there is a sense in which the second question from above is wrongheaded: difference and identity are, so to speak, features of the same ‘ideological apparatus’ (namely, that of quantification), so there is no real decision to be made about which to treat as basic. If this is correct, then the consequences for a theory's ontological parsimony that result from treating difference, identity, or both as basic are just the same as those that issue from the employment of quantification within a theory – namely, one's theory thereby incurs an ontological commitment to things. (shrink)