Ross Cameron

_The Routledge Companion to Metaphysics_ is an outstanding, comprehensive and accessible guide to the major themes, thinkers, and issues in metaphysics. The _Companion _features over fifty specially commissioned chapters from international scholars which are organized into three clear parts: History of Metaphysics Ontology Metaphysics and Science. Each section features an introduction which places the range of essays in context, while an extensive glossary allows easy reference to key terms and definitions. _The Routledge Companion to Metaphysics_ is essential reading for students of philosophy and anyone interested in surveying the central topics and problems in metaphysics from causation to vagueness and from Plato and Aristotle to the present-day.

_The Routledge Companion to Metaphysics_ is an outstanding, comprehensive and accessible guide to the major themes, thinkers, and issues in metaphysics. The _Companion _features over fifty specially commissioned chapters from international scholars which are organized into three clear parts: History of Metaphysics Ontology Metaphysics and Science. Each section features an introduction which places the range of essays in context, while an extensive glossary allows easy reference to key terms and definitions. The Routledge Companion to Metaphysics is essential reading for students of philosophy and anyone interested in surveying the central topics and problems in metaphysics from causation to vagueness and from Plato and Aristotle to the present-day.

Simon Blackburn posed a dilemma for any realist attempt to identify the source of necessity. Either the facts appealed to to ground modal truth are themselves necessary, or they are contingent. If necessary, we begin the process towards regress; but if contingent, we undermine the necessity whose source we wanted to explain. Bob Hale attempts to blunt both horns of this dilemma. In this paper I examine their respective positions and attempt to clear up some confusions on either side. I come to defend Hale’s conclusion that both horns of the dilemma can be resisted. I end by defending my own account of the source of necessity, and showing why it does not fall victim to Blackburn’s problem.

This thesis concerns the source of modal truth. I aim to answer the question: what is it in virtue of which there are truths concerning what must have been the case as a matter of necessity, or could have been the case but isn't. I begin by looking at a dilemma put forward by Simon Blackburn which attempts to show that any realist answer to this question must fail, and I conclude that either horn of his dilemma can be resisted. I then move on to clarify the nature of the propositions whose truth I am aiming to find the source of. I distinguish necessity de re from necessity de dicto, and argue for a counterpart theoretic treatment of necessity de re. As a result, I argue that there is no special problem concerning the source of de re modal facts. The problem is simply to account for what it is in virtue of which there are qualitative ways the world could have been, and qualitative ways it couldn't have been. I look at two ways to answer this question: by appealing to truthmakers in the actual world, or by appealing to non-actual ontology. I develop a theory of truthmakers, but argue that it is unlikely that there are truthmakers for modal truths among the ontology of the actual. I look at the main possibilist ontology, David Lewis' modal realism, but argue that warrant for that ontology is unobtainable, and that we shouldn't admit non-actual possibilia into our ontology. I end by sketching a quasi-conventionalist approach to modality which denies that there are modal facts, but nevertheless allows that we can speak truly when we use modal language.

Skow argues that the best metaphysic of objective becoming is the moving spotlight theory. I agree, but I think the best version of the moving spotlight theory is not amongst the theories Skow describes. I look at Skow's moving spotlight theories that invoke an extra dimension of supertime, or new primitive supertense operators, or that make presentness a fundamentally relational phenomenon, and I raise some problems for these views. I argue that the moving spotlighter should take presentness to be an absolute phenomenon that changes in time. This has consequences for what it means to say the past is real.

© The Author 2017. Published by Oxford University Press on behalf of The Analysis Trust. All rights reserved. For Permissions, please email: [email protected] to the B-Theory, the God’s-eye perspective on reality is an atemporal one: it describes how things are across time – this happens, then that, then this. The B-Theorist holds that the ultimate account of reality does not change. Change is simply variation from one temporal point of reality to another. How things are across time does not change.According to the most popular A-Theory,1 presentism, the God’s-eye perspective on reality is a temporal one: it describes how things are now. This is what is happening now, although that did happen and this will happen. The presentist holds that the ultimate account of reality changes. Since different things did and will happen, different accounts of reality were and will be true....Moving Spotlight theories...

I reply to Miller, Sider and Skow’s comments on my book The Moving Spotlight. I aim to make clearer the epistemic argument against non-presentist A-theories of time, and why I avoid it. I provide further elaboration of the moving spotlight view, and why I think there is real change in important features of things on this metaphysic. I explain further what I think is required for there to be genuine temporal passage, and why there is such a thing according to the moving spotlight view. I defend my argument that endurantism is incompatible with the B-theory.

In his Truth and Ontology,1 Trenton Merricks argues against the truthmaker principle: Truthmaker: ∀p( p → ∃xxᮀ(Exx → p)). Truthmaker says that for any true proposition, there are some things whose existence guarantees the truth of that proposition: that is, some things which couldn’t all exist and the proposition fail to be true. His main arguments against Truthmaker are that there cannot be satisfactory truthmakers for (i) negative existentials, (ii) modal truths, (iii) truths about the past (given that presentism is true) and (iv) certain subjunctive conditionals, in particular so-called ‘counterfactuals of freedom’ and dispositional conditionals. I’m going to concentrate on the first three of these. But first I’ll say a bit about why we should care about Truthmaker. Merricks says that “No one gives much of an argument for Truthmaker. Instead, Truthmaker’s main support comes from something like the brute intuition that what is true depends in a non-trivial way on what there is” ( p. 2). He is, unfortunately, correct that truthmaker theorists have in general not been very good at motivating their theory. Too often is Truthmaker taken to be obvious, or an obvious consequence of realism, when really it is neither. But I think we can do better

Orthodoxy says that the thesis that composition is identity (CAI) entails universalism: the claim that any collection of entities has a sum. If this is true it counts in favour of CAI, since a thesis about the nature of composition that settles the otherwise intractable special composition question (SCQ) is desirable. But I argue that it is false: CAI is compatible with the many forms of restricted composition, and SCQ is no easier to answer given CAI than otherwise. Furthermore, in seeing why this is the case we reveal an objection to CAI: that it allows for the facts concerning what there is to be settled whilst leaving open the question about what is identical to what.

I begin by contrasting three approaches one can take to the distinction between the essential and accidental properties: an ontological, a deflationary, and a mind‐dependent approach. I then go on to apply that distinction to the necessary a posteriori, and defend the deflationist view. Finally I apply the distinction to modal truth in general and argue that the deflationist position lets us avoid an otherwise pressing problem for the actualist: the problem of accounting for the source of modal truth.

Simon Blackburn posed a dilemma for any realist attempt to identify the source of necessity. Either the facts appealed to to ground modal truth are themselves necessary, or they are contingent. If necessary, we begin the process towards regress; but if contingent, we undermine the necessity whose source we wanted to explain. Bob Hale attempts to blunt both horns of this dilemma. In this paper I examine their respective positions and attempt to clear up some confusions on either side. I come to defend Hale’s conclusion that both horns of the dilemma can be resisted. I end by defending my own account of the source of necessity, and showing why it does not fall victim to Blackburn’s problem.

Non-well-founded set theories allow set-theoretic exotica that standard ZFC will not allow, such as a set that has itself as its sole member. We can distinguish plenitudinous non-well-founded set theories, such as Boffa set theory, that allow infinitely many such sets, from restrictive theories, such as Finsler-Aczel or AFA, that allow exactly one. Plenitudinous non-well-founded set theories face a puzzle: nothing seems to explain the identity or distinctness of various of the sets they countenance. In this paper I aim to sharpen this puzzle, make clear who it does and does not apply to and, ultimately, to argue in favor of a plenitudinous theory like Boffa.

We examine moving spotlight theories of time: theories according to which there are past and future events and an objective present moment. In Section 1, we briefly discuss the origins of the view. In Section 2, we describe the traditional moving spotlight view, which we understand as an ‘enriched’ B-theory of time, and raise some problems for that view. In the next two sections, we describe versions of the moving spotlight view that we think are better and which solve those problems. In Section 3, we describe a version of the view that combines permanentism – the thesis that all things always exist – with propositional temporalism, the thesis that some propositions are sometimes true and sometimes false. In Section 4, we discuss a version of the view that is like an ‘enriched’ presentism. We conclude with some brief thoughts on issues that remain outstanding.