Katherine Hawley

(1971 - 2021)

I claim that, if persisting objects have temporal parts, then there are non-supervenient relations between those temporal parts. These are relations which are not determined by intrinsic properties of the temporal parts. I use the Kripke-Armstrong 'rotating homogeneous disc' argument in order to establish this claim, and in doing so I defend and develop that argument. This involves a discussion of instantaneous velocity, and of the causes and effects of rotation. Finally, I compare alternative responses to the rotating disc argument, and consider the implications of my arguments for the doctrines of Humean Supervenience and unrestricted mereology.

‘Fusion’ is a philosophical term of art, with a variety of uses. First, it is often a synonym for ‘sum’. In this sense, a is a fusion of b, c and d iff b, c and d are parts of a, and every part of a shares a part with b, c or d. So a cat is a fusion of the cells which compose it, and the same cat is a fusion of the molecules which compose it. Relatedly, ‘fusion’ can refer to the occurrence of such composition: philosophers disagree about whether fusion is widespread, about whether it can be a vague matter, and so on.

E.J. Lowe claims that quantum physics provides examples of ontic indeterminacy, of vagueness in the world. Any such claim must confront the Evans-Salmon argument to the effect that the notion of ontic indeterminacy is simply incoherent (Evans 1978, Salmon 1981: 243-46). Lowe argues that a standard version of the Evans-Salmon argument fails quite generally (Lowe 1994). Harold Noonan (1995) has outlined a non-standard version of the argument, but Lowe argues that this non-standard version fails for specifically quantum mechanical reasons (Lowe 1997). He claims that it is perfectly coherent to suppose that his quantum case is an example of ontic indeterminacy. In this paper, I raise some objections to Lowe's claim.

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.

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

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).

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