Philosophers often talk as if what it takes for a person to persist through time were up to us, as individuals or as a linguistic community, to decide. In most ordinary situations it might be fully determinate whether someone has survived or perished: barring some unforeseen catastrophe, it is clear enough that you will still exist ten minutes from now, for example. But there is no shortage of actual and imaginary situations where it is not so clear whether one survives. (...) Here reasonable people may disagree. There are "fission" cases where each of one's cerebral hemispheres is transplanted into a different head; Star-Trek-style "teletransportation" stories; actual cases of brain damage so severe that one can never again regain consciousness, even though one's circulation, breathing, digestion, and other "animal" functions continue; and stories where one's brain cells are gradually removed and replaced by cells from someone else, to name only a few favorites. (shrink)

This paper is concerned with the paradox of decrease. Its aim is to defend the answer to this puzzle that was propounded by its originator, namely, the Stoic philosopher Chrysippus. The main trouble with this answer to the paradox is that it has the seemingly problematic implication that a material thing could perish due merely to extrinsic change. It follows that in order to defend Chrysippus’ answer to the paradox, one has to explain how it could be that Theon is (...) destroyed by the amputation without changing intrinsically. In this paper, I shall answer this challenge by appealing to the broadly Aristotelian idea that at least some of the proper parts of a material substance are ontologically dependent on that substance. I will also appeal to this idea in order to offer a new solution to the structurally similar paradox of increase. In this way, we will end up with a unified solution to two structurally similar paradoxes. (shrink)

The Doctrine of Microphysical Supervenience states that microphysical duplicates cannot differ in their intrinsic properties. According to Merricks :59–71, 1998a, Objects and persons, Oxford University Press, 2001), however, this thesis is false, since microphysical duplicates can differ with respect to the intrinsic property of consciousness. In my view, Merricks’ argument is plausible, and extant attempts to reject it are problematic. However, the argument also threatens to make consciousness appear mysterious, by implying that consciousness facts fail to be microphysically determined and (...) that there can be brute and inexplicable differences in consciousness between material things. The paper therefore develops an account that can respect the soundness of Merricks’ argument while avoiding these problematic consequences. At the heart of the proposal is the idea that consciousness can be microphysically grounded despite failing to microphysical supervene. The proposed view also has the interesting consequence that consciousness is an intrinsic property despite depending on extrinsic factors for its instantiation. (shrink)

Are grounding claims fully general in character? If an object a is F in virtue of being G, does it follow that anything that’s G is F for that reason? According to the thesis of Weak Formality, the answer here is ‘yes’. In this paper, however, I argue that there is philosophical utility in rejecting this thesis. More exactly, I argue that two currently unresolved problems in contemporary metaphysics can be dealt with if we hold that there can be cases (...) of ‘kind-dependent grounding’, the key thought being that once we allow for such cases, we must also accept that Weak Formality is false. (shrink)

An encyclopedia entry which covers various revisionary conceptions of which macroscopic objects there are, and the puzzles and arguments that motivate these conceptions: sorites arguments, the argument from vagueness, the puzzles of material constitution, arguments against indeterminate identity, arguments from arbitrariness, debunking arguments, the overdetermination argument, and the problem of the many.

Traditionally, this puzzle has been solved in various ways. Aristotle, for example, distinguished between “accidental” and “essential” changes. Accidental changes are ones that don't result in a change in an objects' identity after the change, such as when a house is painted, or one's hair turns gray, etc. Aristotle thought of these as changes in the accidental properties of a thing. Essential changes, by contrast, are those which don't preserve the identity of the object when it changes, such as when (...) a house burns to the ground and becomes ashes, or when someone dies. Armed with these distinctions, Aristotle would then say that, in the case of accidental changes, (1) and (2) are both false—a changing thing can really change one of its “accidental properties” and yet literally remain one and the same thing before and after the change. (shrink)