Online research in philosophy

A typical human person has privileged epistemic access to its identity over time in virtue of having a first-person point of view. In explaining this phenomenon in terms of an intimate relation of self-attribution or the like, I infer that a typical human person has direct consciousness of itself through inner awareness or personal memory. Direct consciousness of oneself is consciousness of oneself, but not by consciousness of something else. Yet, a perduring human person, $S_p$, i.e., a human person with temporal parts, is identical with the complete series of its temporal parts. I argue that because $S_p$ is diverse from any incomplete series of its temporal parts, and because $S_p$ cannot be conscious of all of its temporal parts through inner awareness or personal memory, $S_p$ cannot have direct consciousness of itself. I conclude that a human person endures, i.e., wholly exists at each of the times it exists.

Suppose a certain man, Dion, has his foot amputated, and lives to tell the tale. That tale involves a well-known metaphysical puzzle, for most of us assume that there was, before the operation, an object made up of all of Dion’s parts except those that overlapped with his foot-- ”all of Dion except for his foot”, we might say, or Dion’s “foot-complement”. Call that object Theon. (Anyone who doubts that there is such a thing as Dion’s undetached foot-complement may imagine that ‘Theon’ is a name for Dion’s undetached head. Surely there is such a thing as Dion’s head? And surely Dion could, in principle, survive if his head were detached from the rest of him and kept alive?) It seems obvious that Theon, like Dion, continues to exist after the operation, for you cannot destroy an object merely by changing its surroundings--merely by removing something that was never a part of it. The puzzle, then (which might be called the problem of undetached parts), is how Dion and Theon are related after the operation. The most common answer to this question is that Dion and Theon come to occupy just the same region of space and to be made of just the same matter after the operation. The next-mostpopular answer is that Dion and Theon are made up of temporal parts, and while those of their temporal parts that “occur” before the operation only partly overlap, Dion and Theon have the very same post-operative temporal parts. Much as two roads can merge and have spatial parts in common, Dion and Theon merge and have temporal parts in common. Less popular accounts of the relation between Dion and Theon involve relativizing identity to concepts or times, and denying that there is such a thing as Theon. Michael Burke has recently proposed an intriguing new solution (or resurrected an ancient one) to the problem of undetached parts. [1] He argues that, despite appearances, Theon-- Dion’s foot-complement--ceases to exist when Dion’s foot is removed..

Ignoring the temporal dimension, an object such as a railway tunnel or a human body is a three-dimensional whole composed of three-dimensional parts. The four-dimensionalist holds that a physical object exhibiting identity across time—Descartes, for example—is a four-dimensional whole composed of 'briefer' four-dimensional objects, its temporal parts. Peter van Inwagen (1990) has argued that four-dimensionalism cannot be sustained, or at best can be sustained only by a counterpart theorist. We argue that different schemes of individuation of temporal parts are available, which undermines van Inwagen's argument.

In this paper, I try to make a bundle theory of objects consistentwith a temporal parts theory of object persistence. To that end,I propose that such bundles are made up of tropes includingthe co-instantiation relation.

I suggest that Carter and Hestevold's arguments for L1 and L2 can be given a chance to succeed if (i) everywhere in them that we find an occurrence of the thesis Transient Time we replace it with an occurrence of Presentism, and (ii) everywhere in them that we find an occurrence of the thesis Static Time we replace it with an occurrence of Presentism's denial. I'm fairly confident that their arguments for L1 would succeed if these changes were made. (If Presentism is true, nothing has temporal parts, for some at least of the temporal parts of a thing extended in time must be past or future. But if nothing has temporal parts, Endurance must be true.) I'm less confident that their arguments for L2 would succeed if those changes were made. But if the changes that I suggest are not made, the arguments for L1 and L2 certainly fail.

What is a temporal part? Most accounts explain it in terms of timeless parthood: a thing's having a part without temporal qualification. Some find this hard to understand, and thus find the view that persisting things have temporal parts—four-dimensionalism—unintelligible. T. Sider offers to help by defining temporal parthood in terms of a thing's having a part at a time. I argue that no such account can capture the notion of a temporal part that figures in orthodox four-dimensionalism: temporal parts must be timeless parts. This enables us to state four-dimensionalism more clearly.

If ordinary objects have temporal parts, then temporal predications have the following truth conditions: necessarily, ( a is F) at t iff a has a temporal part that is located at t and that is F. If ordinary objects have temporal counterparts, then, necessarily, ( a is F) at t iff a has a temporal counterpart that is located at t and that is F. The temporal-parts account allows temporal predication to be closed under the parthood relation: since all that is required to be F at t is to have a temporal part, a t , that is located at t and that is F, every object that has a t as a temporal part is F at t . Similarly for the temporal-counterparts account. Both closure under parthood and closure under counterparthood are shown to have unacceptable consequences. Then strategies for avoiding closure are considered and rejected.

What is a temporal part? Most accounts explain it in terms of timeless parthood: a thing's having a part without temporal qualification. Some find this hard to understand, and thus find the view that persisting things have temporal parts--fourdimensionalism--unintelligible. T. Sider offers to help by defining temporal parthood in terms of a thing's having a part at a time. I argue that no such account can capture the notion of a temporal part that figures in orthodox four-dimensionalism: temporal parts must be timeless parts. This enables us to state four-dimensionalism more clearly.

Temporal parts are analogous to spatial parts: just as the conference has one spatial part which occupies the seminar room, and another which occupies the lecture hall, it has one temporal part which ‘occupies’ Friday and another which ‘occupies’ Saturday. These temporal parts of the conference have half-hour coffee-breaks as temporal parts of their own; these coffee-breaks are also temporal parts of the whole conference.

Those who believe that ordinary things have temporal as well as spatial parts must give an account of the truth conditions of temporally modified predications of the form ‘a is F at t ’ in terms of temporal parts. I will argue that the friend of temporal parts is committed to an account of temporal predication that is incompatible with the classical principle of predicate abstraction.