Eli Hirsch

The Evans-Salmon position on vague identity has deservedly elicited a large response in the literature. I think it is in fact among the most provocative metaphysical ideas to appear in recent years. I will try to show in this paper, however, that the position is vulnerable to a fundamental criticism that seems to have been virtually ignored in the many discussions of it. I take the Evans-Salmon position to consist of the following two theses: Thesis I. There cannot be objects x and y such that it is indeterminate whether x is (identical with) y. Thesis II. The only way for an identity sentence to be indeterminate in truth-value is if one of the expressions flanking the identity symbol is referentially ambiguous.] The argument for Thesis I is essentially as follows. We are assuming that the sense of identity under discussion satisfies the standard formal logic of identity including Leibniz's Law. Suppose, now, that it is indeterminate whether x is y. Since it is determinate that x is x, x differs from y with respect to the property of being determinately x, from which it follows by Leibniz's Law that x is not y. Since the supposition that it is indeterminate whether x is y leads to the conclusion that x is not y, this supposition is incoherent.

I would expect many readers of my book to want to agree with either Mark Heller or Alan Sidelle. The very idea of “rational constraints on lexicons” will immediately suggest to many people that either the constraints are of a purely pragmatic nature or there really are no such constraints. I can take some cold comfort in the fact that many philosophers will join me in rejecting, and many others will join me in rejecting, but since I have nothing to offer in place of these positions—except mystification—I’m afraid that few will join me in rejecting both of them.

We can describe languages in which no words refer to objects. Such languages may contain sentences equivalent to any sentences of English, and hence may allow for as much objectivity as English does. It is wrong to try to deal with such languages by claiming that there are more objects than those accepted by common sense ontology. The correct move is rather to acknowledge a sense in which the concept of an object might have been different. A consequence of this position is that we cannot have a general semantics applicable to every describable language in which words are referentially connected to objects. The point here is not that reference may be inscrutable, but that different concepts of ‘referring to an object’ may be required for different languages.

Two main claims are defended in this paper: first, that typical disputes in the literature about the ontology of physical objects are merely verbal; second, that the proper way to resolve these disputes is by appealing to common sense or ordinary language. A verbal dispute is characterized not in terms of private idiolects, but in terms of different linguistic communities representing different positions. If we imagine a community that makes Chisholm's mereological essentialist assertions, and another community that makes Lewis's four-dimensionalist assertions, the members of each community speak the truth in their respective languages. This follows from an application of the principle of interpretive charity to the two communities.