Sorensen here offers a unified solution to a large family of philosophical puzzles and paradoxes through a study of "blindspots": consistent propositions that cannot be rationally accepted by certain individuals even though they might by true.

Persistence through time is like extension through space. A road has spatial parts in the subregions of the region of space it occupies; likewise, an object that exists in time has temporal parts in the various subregions of the total region of time it occupies. This view — known variously as four dimensionalism, the doctrine of temporal parts, and the theory that objects “perdure” — is opposed to “three dimensionalism”, the doctrine that things “endure”, or are “wholly present”.1 I will (...) attempt to resolve this dispute in favor of four dimensionalism by means of a novel argument based on considerations of vagueness. But before argument in this area can be productive, I believe we must become much clearer than is customary about exactly what the dispute is, for the usual ways of formulating the dispute are flawed, especially where three dimensionalism is concerned. (shrink)

How does an object persist through change? How can a book, for example, open in the morning and shut in the afternoon, persist through a change that involves the incompatible properties of being open and being shut? The goal of this reader is to inform and reframe the philosophical debate around persistence; it presents influential accounts of the problem that range from classic papers by W. V. O. Quine, David Lewis, and Judith Jarvis Thomson to recent work by contemporary philosophers. (...) The authors take on the question of persistence by examining three broad approaches: perdurantism, which holds that change over time is analogous to change over space; exdurantism, according to which identity over time is analogous to identity across possible worlds; and endurantism, which holds that ordinary objects persist by enduring. Each of these approaches appears to be coherent, but each also has its own metaphysical problems. Persistence includes papers that argue for perdurantism, exdurantism, or endurantism, as well as papers that explore some metaphysical difficulties challenging each account. In this way the collection allows readers to balance the trade-offs of each approach in terms of intuitiveness, theoretical attractiveness, and elegance.Contributors:Yuri Balashov, William Carter, Graeme Forbes, Sally Haslanger, Katherine Hawley, H. S. Hestevold, Mark Hinchliffe, Mark Johnston, Roxanne Marie Kurtz, David K. Lewis, Ned Markosian, D. H. Mellor, W. V. O. Quine, Theodore Sider, Richard Taylor, Judith Jarvis Thomson, Peter van Inwagen, Dean Zimmerman. (shrink)

Consider an object or property a and the predicate F. Then a is vague if there are questions of the form: Is a F? that have no yes-or-no answers. In brief, vague properties and kinds have borderline instances and composite objects have borderline constituents. I'll use the expression "borderline cases" as a covering term for both. ;Having borderline cases is compatible with precision so long as every case is either borderline F, determinately F or determinately not F. Thus, in addition (...) to borderline cases, vagueness requires "fuzzy borders". A has fuzzy borders if there is no sharp line between a's borderline cases, a's determinate cases and a's determinate non-cases. To illustrate, loudness is vague because in a continuum of gradually increasing volume, there is no fact about where the last definite loud noise is and where the first borderline noise is. ;Actual borderline cases are not required for vagueness. Suppose actual noises are either ear-shatteringly loud or silent. Even so, loudness is vague since it could have borderline instances. Just so for objects. Suppose a table is cleanly bounded such that there is a sharp break between the table and its surroundings. Still, that table is vague since there are worlds at which it is indeterminate whether some wood molecule a is, or is not, part of that table. ;There are three views about which things can be vague. On the linguistic view, vagueness is solely a feature of expressions. On the nihilistic view, nothing is vague because vagueness is incoherent. Pitted against these views is the ontological conception of vagueness according to which borderline instances and constituents arise due to genuine indeterminacy in nature. ;My dissertation defends the ontological conception. I argue against the adequacy of the theory's rivals, disarm a damaging objection and demonstrate the causal superiority of vague events. Anyone familiar with the literature on vagueness will notice that only a subset of issues are discussed. What I offer is preliminary--I hope only to make the theory of ontological vagueness attractive enough to merit future work. (shrink)