In this book, Eli Hirsch focuses on identity through time, first with respect to ordinary bodies, then underlying matter, and eventually persons.

A sense of unity -- Basic objects : a reply to Xu -- Objectivity without objects -- The vagueness of identity -- Quantifier variance and realism -- Against revisionary ontology -- Comments on Theodore Sider's four dimensionalism -- Sosa's existential relativism -- Physical-object ontology, verbal disputes, and common sense -- Ontological arguments : interpretive charity and quantifier variance -- Language, ontology, and structure -- Ontology and alternative 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. (shrink)

The central question in this book is why it seems reasonable for the words of our language to divide up the world in ordinary ways rather than other imaginable ways. Hirsch calls this the division problem. His book aims to bring this problem into sharp focus, to distinguish it from various related problems, and to consider the best prospects for solving it. In exploring various possible responses to the division problem, Hirsch examines series of "division principles" which purport to express (...) rational constraints on how our words ought to classify and individuate. The ensuing discussion deals with a wide range of metaphysical and epistemological topics, including projectibility and similarity, alternative analyses of natural properties and things, the inscrutability of reference, and the relevance of such pragmatic notions as salience and economy. The final chapters of the book develop what Hirsch contends is the most promising response to the division problem: a theory in which constraints on classification and individuation are seen to derive from the necessary structure of "fine-grained" propositions and the necessary dependence of some concepts on others. (shrink)

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. (shrink)

In the work of both Matti Eklund and John Hawthorne there is an influential semantic argument for a maximally expansive ontology that is thought to undermine even modest forms of quantifier variance. The crucial premise of the argument holds that it is impossible for an ontologically "smaller" language to give a Tarskian semantics for an ontologically "bigger" language. After explaining the Eklund-Hawthorne argument (in section I), we show this crucial premise to be mistaken (in section II) by developing a Tarskian (...) semantics for a mereological universalist language within a mereological nihilist language (a case which we, and Eklund and Hawthorne, take as representative). After developing this semantics we step back (in section III) to discuss the philosophical motivations behind the Eklund- Hawthorne argument’s demand for a semantics. We ultimately conclude that quantifier variantists can meet any demand for a semantics that might reasonably be imposed upon them. (shrink)

Quantifier variance is a well-known view in contemporary metaontology, but it remains very widely misunderstood by critics. Here we briefly and clearly explain the metasemantics of quantifier variance and distinguish between modest and strong forms of variance (Section I), explain some key applications (Section II), clear up some misunderstandings and address objections (Section III), and point the way toward future directions of quantifier-variance-related research (Section IV).

Theodore Sider has given us a terrific book, bursting at the seams with new arguments and new takes on old arguments. Whether or not one is convinced by his conclusions, the thoroughness, lucidity, fair-mindedness—and the sheer exuberance—of his discussions make Four Dimensionalism a major contribution to contemporary metaphysics.

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. (shrink)

This chapter contains section titled: Existential Relativism and Explosionism Existential Relativism and Quantifier Relativism.

According to one view, death is bad for the one who dies. The challenge for this view is to explain exactly why and when death is bad for the one who dies. According to an alternative view, death is not actually bad for the one who dies. There is a third alternative, according to which the thought of one’s own death elicits an experience that reveals the horror of one’s own death in a way that is ineffable. This paper explores (...) this third alternative. (shrink)

It is difficult to understand questions about the evolution of ants. It seems often to be assumed that there are specific features that ants possess because of the "survival value" of such features. This makes very little sense, because it is very hard to believe that there are any features at all that can be viewed as having survival value for ants.

What I call the Similarity Principle says that a word ought to denote a class of things that are more similar to each other than to other things. A closely related formulation, which I’ll here take to be equivalent, is that a word ought to denote a class of things having something in common with each other that they don’t have in common with other things. The Similarity Principle is an example of an intuitively rational constraint on the lexicon of (...) a language. If we imagine such strange words as “gricular” or “carple”, we feel intuitively that there would be something absurd about having such words in our language, and one explanation of this—indeed the explanation that is likely first to come to a person’s mind in some rudimentary form—is that these words violate the Similarity Principle. (shrink)

Timothy Williamson has argued that the safety condition on knowledge places certain limits on iterations of knowledge. But at the same time, Williamson claims that interpersonal iterations of knowledge aren’t so restricted as to rule out ordinary cases. The present authors show that Williamson’s discussion misconstrues the challenge to iterated interpersonal knowledge. The proper argument against interpersonal iterations is rather what the authors call a third-person argument that does not share the major weaknesses of the argument Williamson considers. The challenge (...) that the safety condition poses to interpersonal iterations of knowledge therefore seems robust, even in ordinary cases. But the authors also identify an underlying assumption that their argument relies on, and they show that Williamson’s original argument as well as his argument against intrapersonal iterations of knowledge rely on analogous assumptions. In assessing the extent of the clash between safety and iterated knowledge, the focus must be on the viability of these assumptions. (shrink)