Standard lore has it that a proper name is a temporally rigid designator. It picks out the same entity at every time at which it picks out an entity at all. If the entity in question is an enduring continuant then we know what this means, though we are also stuck with a host of metaphysical puzzles concerning endurance itself. If the entity in question is a perdurant then the rigidity claim is trivial, though one is left wondering how it (...) is that different speakers ever manage to pick out one and the same entity when a host of suitable, overlapping candidates are available. But what if the entity in question is neither a continuant nor a perdurant? What if the things we talk about in ordinary language are time-bound entities that cannot truly be said to persist through time, or stage sequences whose unity resides exclusively in our minds--like the “waves” at the stadium or the characters of a cartoon? In such cases the rigidity claim can’t be right and a counterpart-theoretic semantics seems required. Is that bad? I say it isn’t. And it had better not be, if that turns out to be the best metaphysical option we have. (shrink)

The theory of variable embodiments has been primarily formulated to model ordinary objects as things that change their parts over time. A variable embodiment /f/ is a sui generis whole constructed from a principle f, the principle of a variable embodiment, and it is manifested at different times by different things picked out by such a principle f. This principle is usually clarified as a function that picks out, at any given time the variable embodiment exists, its corresponding manifestation at (...) that time, and it fails to pick out anything at any other time. The first purpose of this article is to examine and refute three natural understandings of such a principle. Specifically, first, we argue against the view that it should be understood extensionally as either a partial function or total function. Next, we provide some motivations to reject the understanding of the principle as a function in intensional terms, where the notion of intension is analyzed in terms of a specific version of a possible world semantics. The second goal of the article is to make it plausible that the principle has an intensional character and, on the basis of the results achieved, to formulate some constraints that an account of such a principle should meet. (shrink)

Most four-dimensionalists, including both worm and stage theorists, endorse mereological universalism, the thesis that any class of objects has a fusion. But the marriage of fourdimensionalism and universalism is unfortunate and unprofitable: it creates a recalcitrant problem for stage theory’s account of lingering properties, such as writing ‘War and Piece’ and traveling across the tennis court, which take time to be instantiated. This makes it necessary to impose a natural restriction on diachronic composition.

Material objects extend through space by having different spatial parts in different places. But how do they persist through time? According to some philosophers, things have temporal parts as well as spatial parts: accepting this is supposed to help us solve a whole bunch of metaphysical problems, and keep our philosophy in line with modern physics. Other philosophers disagree, arguing that neither metaphysics nor physics give us good reason to believe in temporal parts.