Katherine Hawley

(1971 - 2021)

In his Material Beings, Peter van Inwagen distinguishes two questions about parthood. What are the conditions necessary and sufficient for some things jointly to compose a whole? What are the conditions necessary and sufficient for a thing to have proper parts? The first of these, the Special Composition Question (SCQ), has been widely discussed, and David Lewis has argued that an important constraint on any answer to the SCQ is that it should not permit borderline cases of composition. This is a far-reaching claim, since many plausible-seeming accounts of composition do permit borderline cases. Ned Markosian has recently directed our attention to the second, the neglected Inverse Special Composition Question (ISCQ). I will argue that those who accept Lewis’s constraint on answers to the SCQ should accept an analogous constraint on answers to the ISCQ, and I will discuss the effects of such a constraint.

You can trust your friends. You should trust your friends. Not all of your friends all of the time: you can reasonably trust different friends to different degrees, and in different domains. Still, we often trust our friends, and it is often reasonable to do so. Why is this? In this paper I explore how and whether friendship gives us reasons to trust our friends, reasons which may outstrip or conflict with our epistemic reasons. In the final section, I will sketch some related questions concerning trust based on the trustee’s race, gender, or other social identity.

Take this banana. It is now yellow, and when I bought it yesterday it was green. How can a single object be both green all over and yellow all over without contradiction? It is, of course, the passage of time which dissolves the contradiction, but how is this possible? How can a banana ripen? These questions raise the problem of change. The problem is sometimes called the problem of temporary intrinsics, but, as I shall explain below, this emphasis on intrinsic properties is misleading. For my more recent thoughts in this area, please see my 'David Lewis on Persistence' (2015).

Closest-continuer or best-candidate accounts of persistence seem deeply unsatisfactory, but it’s hard to say why. The standard criticism is that such accounts violate the ‘only a and b’ rule, but this criticism merely highlights a feature of the accounts without explaining why the feature is unacceptable. Another concern is that such accounts violate some principle about the supervenience of persistence facts upon local or intrinsic facts. But, again, we do not seem to have an independent justification for this supervenience claim. Instead, I argue that closest continuer accounts are committed to unexplained correlations between distinct existences, and that this is their fundamental flaw. We can have independent justification for rejecting such correlations, but what the justification is depends upon much broader issues in ontology. There is no one-size-fits all objection to closest-continuer accounts of persistence

Analytic metaphysics is in resurgence; there is renewed and vigorous interest in topics such as time, causation, persistence, parthood and possible worlds. We who share this interest often pay lip-service to the idea that metaphysics should be informed by modern science; some take this duty very seriously.2 But there is also a widespread suspicion that science cannot really contribute to metaphysics, and that scientific findings grossly underdetermine metaphysical claims. For some, this prompts the thought ‘so much the worse for metaphysics’; others mutter ‘so much the worse for science’.

I argue that, despite van Inwagen’s pessimism about the task, it is worth looking for answers to his General Composition Question. Such answers or ‘principles of composition’ tell us about the relationship between an object and its parts. I compare principles of composition with criteria of identity, arguing that, just as different sorts of thing satisfy different criteria of identity, they may satisfy different principles of composition. Variety in criteria of identity is not taken to reflect ontological variety in the identity relation; I discuss whether variety in principles of composition should be taken to reflect ontological variety in the composition relation

Roughly speaking, perdurantism is the view that ordinary objects persist through time by having temporal parts, whilst endurantism is the view that they persist by being wholly present at different times. (Speaking less roughly will be important later.) It is often thought that perdurantists have an advantage over endurantists when dealing with objects which appear to coincide temporarily: lumps, statues, cats, tail-complements, bisected brains, repaired ships, and the like. Some cases – personal fission, for example – seem to involve temporary coincidence between objects of the same kind. Other cases – a cat and its flesh, a statue and its lump – seem to involve objects of different kinds.

This chapter explores the connections between David Lewis's perdurance theory and his Humean supervenience, arguing that his influential argument about temporary intrinsics is best seen in this light. It presents domestic dispute within the anti‐endurantist camp and analyzes the following questions: why does Lewis identify ordinary objects with world‐bound parts of transworld objects, but not with time‐bound parts of transtemporal objects? Given that Lewis is a counterpart theorist about modality, why isn't he a stage theorist about persistence? Humean supervenience in isolation does not entail perdurance theory, even for the actual world. Lewis's treatment of temporary intrinsics in On the Plurality of Worlds forms part of a discussion of both persistence and its modal analogue, for which there is no neutral term. Perdurance theory is challenged by the stage theory of persistence, which identifies ordinary objects with brief stages instead of transtemporal sums of those stages.