There are five individually plausible and jointly incompatible assumptions underlying four familiar puzzles about material constitution. The problem of material constitution just is the fact that these five assumptions are both plausible and incompatible. I will begin by providing a very general statement of the problem. I will present the five assumptions and provide a short argument showing how they conflict with one another. Then, in subsequent sections, I will go on to show how these assumptions underlie each of the (...) four puzzles. I will conclude by providing an exhaustive taxonomy of possible solutions to the problem. (shrink)

The doctrine of the Trinity maintains that there are exactly three divine Persons (Father, Son, and Holy Spirit) but only one God. The philosophical problem raised by this doctrine is well known. On the one hand, the doctrine seems clearly to imply that the divine Persons are numerically distinct. How else could they be ’three’ rather than one? On the other hand, it seems to imply that Father, Son, and Holy Spirit are identical. If each Person is divine, how else (...) could there be exactly ’one’ God? But the divine Persons can’t be both distinct and identical. Thus, the doctrine appears to be incoherent. Some try to solve this problem by appeal to the view that identity is sortal-relative. In this paper, I argue that this strategy is unsuccessful as a stand-alone solution to the problem of the Trinity. (shrink)

William Hasker replies to my arguments against social Trinitarianism, offers some criticism of my own view, and begins a sketch of another account of the Trinity. I reply with some defence of my own theory and some questions about his.

Latin models of the Trinity begin from the existence of one God, and try to explain how one God can be three Persons. I offer an account of this based on an analogy with time-travel. A time-traveler returning to the same point in time repeatedly might have three successive events in his/her life occurring at that one location in public time. So too, God’s life might be such that three distinct parts of His life are always occurring at once, though (...) without any succession between them, and this might give God the triune structure Christian theology believes He has. (shrink)

There are various puzzles that set our intuitions about composition and identity against one another. Four that are particularly well known are the Growing Argument, the Ship of Theseus Puzzle, the Body-minus Argument, and Allan Gibbard’s puzzle about Lumpl and Goliath. Such puzzles have received a great deal of attention in the literature over the past thirty years, and there is an impressive and growing variety of solutions available for each of them. Surprisingly, however, no one has really discussed how (...) all of the different puzzles, and their solutions, are interrelated. On the surface, they seem to raise different problems; but clearly the puzzles are related somehow. They raise similar questions and generate similar sets of possible solutions. But, as yet, nothing has been said about how far the similarities extend. (shrink)

Absolute identity seems at first sight to be presupposed in the branch of formal logic called identity theory. Classical identity theory may be obtained by adjoining a single schema to ordinary quantification theory.