Is the relation between properties and the causal powers they confer necessary, or contingent? Necessary, says Sydney Shoemaker, on pain of skepticism about the properties. Contingent, says David Lewis, swallowing the skeptical conclusion. I shall argue that Lewis is right about the metaphysics, but that Shoemaker and Lewis are wrong about the epistemology. Properties have intrinsic natures (quiddities), which we can know.

This book is a defense of modal realism; the thesis that our world is but one of a plurality of worlds, and that the individuals that inhabit our world are only a few out of all the inhabitants of all the worlds. Lewis argues that the philosophical utility of modal realism is a good reason for believing that it is true.

It is argued that there are three main forms of necessity --the metaphysical, the natural and the normative--and that none of them is reducible to the others or to any other form of necessity. In arguing for a distinctive form of natural necessity, it is necessary to refute a version of the doctrine of scientific essentialism; and in arguing for a distinctive form of normative necessity, it is necessary to refute certain traditional and contemporary versions of ethical naturalism.

Logic begins but does not end with the study of truth and falsity. Within truth there are the modes of truth, ways of being true: necessary truth and contingent truth. When a proposition is true, we may ask whether it could have been false. If so, then it is contingently true. If not, then it is necessarily true; it must be true; it could not have been false. Falsity has modes as well: a false proposition that could not have been (...) true is impossible or necessarily false; one that could have been true is merely contingently false. The proposition that some humans are over seven feet tall is contingently true; the proposition that all humans over seven feet tall are over six feet tall is necessarily true; the proposition that some humans are over seven feet tall and under six feet tall is impossible, and the proposition that some humans are over nine feet tall is contingently false. Of these four modes of truth, let us focus on necessity, plus a fifth: possibility. A proposition is possible if it is or could have been true; hence propositions that are either necessarily true, contingently true, or contingently false are possible. Notions that are similar to the modes of truth in being concerned with what might have been are called modal. Dispositions are modal notions, for example the disposition of fragility. Relatedly, there are counterfactual conditionals, for example “if this glass were dropped, it would break.” And the notion of supervenience is modal.1 But let us focus here on necessity and possibility. Modal words are notoriously ambiguous (or at least context-sensitive2). I may reply to an invitation to give a talk in England by saying “I can’t come; I have to give a talk in California the day before”. This use of “can’t” is perfectly appropriate. But it would be equally appropriate for me to say that I could cancel my talk in California (although that would be rude) and give the talk in England instead. What I cannot do is give both talks.. (shrink)

On the now dominant Quinean view, metaphysics is about what there is. Metaphysics so conceived is concerned with such questions as whether properties exist, whether meanings exist, and whether numbers exist. I will argue for the revival of a more traditional Aristotelian view, on which metaphysics is about what grounds what. Metaphysics so revived does not bother asking whether properties, meanings, and numbers exist (of course they do!) The question is whether or not they are fundamental.

Any property has two sorts of causal features: “forward-looking” ones, having to do with what its instantiation can contribute to causing, and ldquo;backward-looking” ones, having to do with how its instantiation can be caused. Such features of a property are essential to it, and properties sharing all of their causal features are identical. Causal necessity is thus a special case of metaphysical necessity. Appeals to imaginability have no more force against this view than they do against the Kripkean view that (...) statements like “Gold is an element” are metaphysically necessary. (shrink)

In this paper I offer an account of the meaning of must and can within the framework of possible worlds semantics. The paper consists of two parts: the first argues for a relative concept of modality underlying modal words like must and can in natural language. I give preliminary definitions of the meaning of these words which are formulated in terms of logical consequence and compatibility, respectively. The second part discusses one kind of insufficiency in the meaning definitions given in (...) the first part, which arise from the ex falso quodlibet paradox of logical consequence. In stepwise fashion, I make an attempt to avoid most of the consequences of this paradox for the meaning definitions of must and can. (shrink)

Kim argues that weak and global supervenience are too weak to guarantee any sort of dependency. Of the three original forms of supervenience, strong, weak, and global, each commonly wielded across all branches of philosophy, two are thus cast aside as uninteresting or useless. His arguments, however, fail to appreciate the strength of weak and global supervenience. I investigate what weak and global supervenience relations are functionally and how they relate to strong supervenience. For a large class of properties, weak (...) and global supervenience are equivalent to strong supervenience. I then offer a series of arguments showing that it is precisely because of their strength, not their weakness, that both weak and global supervenience are useless in characterizing any dependencies of interest to philosophers. (shrink)

Humeans and non-Humeans reasonably agree that there may be necessary connections between entities that are identical or merely partly distinct—between, e.g., sets and their individual members, fusions and their individual parts, instances of determinates and determinables, members of certain natural kinds and certain of their intrinsic properties, and (especially among physicalists) certain physical and mental states. Humeans maintain, however, that as per “Hume’s Dictum”, there are no necessary connections between entities that are wholly distinct;1 and in particular, no necessary causal (...) connections between such entities (even when the background conditions requisite for causation are in place). The Humean’s differential treatment appears principled, in reflecting that commonly accepted necessary connections involve constitutional relations, whereas wholly distinct entities (notably, causes and effects) do not constitute each other. I’ll argue, however, that the appearance of principle is not genuine, as per the following conditional: Constitutional→Causal: If one accepts certain constitutional necessities, one should accept certain causal necessities. This result provides needed leverage in assessing the two main frameworks in the metaphysics of science, treating natural kinds, causes, laws of nature, and the like. These frameworks differ primarily on whether Hume’s Dictum is taken as a working constraint on theorizing; and it has proved difficult for either side to criticize the other without presupposing their preferred stance on the dictum, hence talking past one another. The arguments for Constitutional→Causal are based, however, in general and independent considerations about what facts in the world might plausibly warrant our beliefs in certain constitutional necessities involving broadly scientific entities. The Humean can respond to these arguments, which reveal a deep tension in their view, at attendant costs of implausibilty and adhocery. The non-Humean framework doesn’t face any such tension between constitutional and causal necessities, however, and so in this respect comes out ahead. (shrink)

Two versions of global supervenience have recently been distinguished from each other. I introduce a third version, which is more likely what people had in mind all along. However, I argue that one of the three versions is equivalent to strong supervenience in every sense that matters, and that neither of the other two versions counts as a genuine determination relation. I conclude that global supervenience has little metaphysically distinctive value.

One of Hume's most well-known works and a masterpiece of philosophy, A Treatise of Human Nature is indubitably worth taking the time to read.

Tn this paper I explore and to an extent defend HS. The main philosophical challenges to HS come from philosophical views that say that nomic concepts-laws, chance, and causation-denote features of the world that fail to supervene on non-nomic features. Lewis rejects these views and has labored mightily to construct HS accounts of nomic concepts. His account of laws is fundamental to his program, since his accounts of the other nomic notions rely on it. Recently, a number of philosophers have (...) criticized Lewis's account, and Humean accounts of laws generally, for delivering, at best, a pale imitation ofthe genuine item. These philosophers think that the notion of law needed by science requires laws-if there are any-to be fundamental features of our world that are completely distinct from and not supervenient on the particular facts that they explain. I side with Lewis against these philosophers. Here I will argue that although Lewis-laws don't fulfill all our philosophical expectations, they do play the roles that science needs laws to play. The metaphysics and epistemology of Humean laws, and more specifically, Lewis-laws, are in much better shape than the metaphysics and epistemology of the main anti-Humean alternatives. However, I do have inisgivings about Lewis's account. Both he and his critics assume that the basic properties are so individuated so that the laws are not metaphysically necessary. If this assumption is rejected, then the question of Humean supervenience lapses. I conclude with a brief discussion of this position. (shrink)

That laws of nature play a vital role in explanation, prediction, and inductive inference is far clearer than the nature of the laws themselves. My hope here is to shed some light on the nature of natural laws by developing and defending the view that they involve genuine relations between properties. Such a position is suggested by Plato, and more recent versions have been sketched by several writers.~ But I am not happy with any of these accounts, not so much (...) because they lack detail or engender minor difficulties, though they do, but because they share a quite fundamental defect. My goal here is to make this defect clear and, more importantly, to present a rather different version of this general conception of laws that avoids it. I begin by considering several features of natural laws and argue that these are best explained by the view that laws involve properties, that this involvement takes the form of a genuine relation between properties, and, finally, that the relation is a metaphysically necessary one. In the second section I start at the other end, and by reflecting on the nature of properties arrive at a similar account of natural laws. In the final section I develop this account in more detail, with emphasis on the nature of the relation between properties it invokes. Along the way several natural objections to the account are answered. (shrink)

In this paper, I argue that the spatiotemporalist approach way of modeling the fundamental constituents, structure, and composition of the world has taken a wrong turn. Spatiotemporalist approaches to fundamental structure take the fundamental nature of the world to be spatiotemporal: they take the category of spatiotemporal to be fundamental. I argue that the debates over the nature of the fundamental space in the physics show us that (i) the fact that it is conceivable that the manifest world could be (...) exactly as it appears to us, even though spatiotemporal entities are not fundamental, means that a central premise of spatiotemporalism, that we may assume, given ordinary experience, that the world is fundamentally spatiotemporal, is false. (ii) Spatiotemporalism must be seen as a contingent, a posteriori physical truth. Finally, (iii) I argue that a metaphysically deeper conclusion follows from the debate over the nature of the fundamental space. The debate in physics over which sort of space is the fundamental space suggests that physicists have discovered that, even if a spacetime is an actual constituent of the world-space category, there is a world-space category that is more fundamental than the category of spacetime. (shrink)

Nonreductive materialism is the dominant position in the philosophy of mind. The global supervenience of the mental on the physical has been thought by some to capture the central idea of nonreductive materialism: that mental properties are ultimately dependent on, but irreducible to, physical properties. But Jaegwon Kim has argued that global psychophysical supervenience does not provide the materialist with the desired dependence of the mental on the physical, and in general that global supervenience is too weak to be an (...) interesting dependence relation. We argue that these arguments are unsound. Along the way, we clarify the relationship between global and strong supervenience, and show clearly what sort of dependence global supervenience provides. (shrink)

There are now several, realist versions of quantum mechanics on offer. On their most straightforward, ontological interpretation, these theories require the existence of an object, the wavefunction, which inhabits an extremely high-dimensional space known as configuration space. This raises the question of how the ordinary three-dimensional space of our acquaintance fits into the ontology of quantum mechanics. Recently, two strategies to address this question have emerged. First, Tim Maudlin, Valia Allori, and her collaborators argue that what I have just called (...) the ‘most straightforward’ interpretation of quantum mechanics is not the correct one. Rather, the correct interpretation of realist quantum mechanics has it describing the world as containing objects that inhabit the ordinary three-dimensional space of our manifest image. By contrast, David Albert and Barry Loewer maintain the straightforward, wavefunction ontology of quantum mechanics, but attempt to show how ordinary, three-dimensional space may in a sense be contained within the high-dimensional configuration space the wavefunction inhabits. This paper critically examines these attempts to locate the ordinary, three-dimensional space of our manifest image “within” the ontology of quantum mechanics. I argue that we can recover most of our manifest image, even if we cannot recover our familiar three-dimensional space. (shrink)

According to the Genuine Modal Realist, there is a plurality of possible worlds, each world nothing more than a maximally inter-related spatiotemporal sum. One advantage claimed for this position is that it offers us the resources to analyse, in a noncircular manner, the modal operators. In this paper, we argue that the prospects for such an analysis are poor. For the analysis of necessity as truth in all worlds to succeed it is not enough that no modal concepts be used (...) in the realist's account of a possible world (a fact we grant); rather, such an analysis will succeed only if the set of worlds that is postulated is complete. By appealing to plausible truths about the number of possible alien natural properties, we show that there are serious difficulties in guaranteeing that such a set exists without taking some modal concept as primitive. Accordingly, at least in its current form, Genuine Modal Realism must curtail its analytic ambitions. (shrink)

Why believe Hume's Dictum, according to which there are, roughly speaking, no necessary connections between wholly distinct entities? Schaffer suggests that HD, at least as applied to causal or nomological connections, is motivated as required by the best account of of counterfactuals---namely, a similarity-based possible worlds account, where the operative notion of similarity requires 'miracles'---more specifically, worlds where entities of the same type that actually exist enter into different laws. The main cited motivations for such an account of similarity are (...) first, that some salient contexts presuppose CF asymmetry, and second, that accounts of CFs failing to presuppose CF asymmetry are epistemologically problematic, such that under conditions of determinism, the variations in initial micro-conditions needed to implement a given counterfactual antecedent would result in so many changes to macro-states that evaluation of CFs would be rendered practically impossible. Against the first reason, I argue that no non-artificial contexts presuppose CF asymmetry; against the second, I observe that such micro-variation is compatible, in principle, with significant similarity as regards macroscopic states of affairs---enough, in particular, to allow CFs to be appropriately evaluated. (shrink)