Physicalism is incompatible with what is known as the possibility of zombies, that is, the possibility of a world physically like ours, but in which there are no conscious experiences. But it is compatible with what is known as the possibility of ghosts, that is, the possibility of a world which is physically like ours, but in which there are additional nonphysical entities. In this paper we argue that a revision to the traditional definition of physicalism designed to accommodate the (...) possibility of ghosts inadvertently accommodates what is known as the possibility of inverted spectra, that is, the possibility of a world which is physically like ours, but in which colour experience is inverted. This consequence is unwelcome, because it is widely agreed that the possibility of inverted spectra is incompatible with physicalism. We argue for a revised definition of physicalism which resolves this problem. We then use our definition to argue that physicalism is not compatible with what is known as the possibility of blockers, that is, the possibility of a world which is physically like ours, but in which additional nonphysical entities have prevented the existence of conscious experience. This undermines Stephan Leuenberger's attempt to defend physicalism from arguments which purport to establish the possibility of zombies. (shrink)

In the first part ("Determination"), I consider different notions of determination, contrast and compare modal with non-modal accounts and then defend two a-modality theses concerning essence and supervenience. I argue, first, that essence is a a-modal notion, i.e. not usefully analysed in terms of metaphysical modality, and then, contra Kit Fine, that essential properties can be exemplified contingently. I argue, second, that supervenience is also an a-modal notion, and that it should be analysed in terms of constitution relations between properties. (...) In the second part ("A Theory of Truthmaking"), I first review the literature on ontological commitment, and argue that the notion of truthmaking is better suited to play its explanatory rôle. I then argue that we should take truthmaker theory seriously, and that we should provide actual truthmakers for all truths there are. In the last chapter of this part, I review Armstrong's truthmaker theories and argue that they are unsatisfactory. I generalise my criticism to an argument against truthmaker necessitarianism, the view that truthmakers necessarily make true the truths they are truthmakers of. In the third part ("Properties and their Kind(s)"), I discuss qualitative determination. I present and endorse the truthmaker argument for universals, and defend universalism against friends of tropes, states of affairs and facts. I then give a novel characterisation of the important class of intrinsic properties, building on Lewis' work. With a workable notion of intrinsicness at hand, I argue that relations are ontologically – but not "ideologically" – dispensable: qualitative determination in general is a matter of intrinsic structure. In the future, I plan to add two parts and to publish my thesis as a book: In the fourth part ("Exemplification"), I argue for the existence of an exemplification relation tying universals and particulars together. I derive theoretical benefits from this relation by providing adverbialist theories of modality and tense and identify exemplification with a type of parthood. In the fifth part ("Qua qua qua"), I investigate the curious and interesting ontological category of so-called "qua-objects" (Picasso-as-a-painter, for example) and argue that they exist, are not identical with transworld indidivuals or modal parts and that they provide (contingent) truthmakers for all true predications. (shrink)

The elucidations and regimentations of grounding offered in the literature standardly take it to be a necessary connection. In particular, authors often assert, or at least assume, that if some facts ground another fact, then the obtaining of the former necessitates the latter; and moreover, that grounding is an internal relation, in the sense of being necessitated by the existence of the relata. In this article, I challenge the necessitarian orthodoxy about grounding by offering two prima facie counterexamples. First, some (...) physical facts may ground a certain phenomenal fact without necessitating it; and they may co-exist with the latter without grounding it. Second, some instantiations of categorical properties may ground the instantiation of a dispositional one without necessitating it; and they may co-exist without grounding it. After arguing that these may be genuine counterexamples, I ask whether there are modal constraints on grounding that are not threatened by them. I propose two: that grounding supervenes on what facts there are, and that every grounded fact supervenes on what grounds there are. Finally, I attempt to provide a rigorous formulation of the latter supervenience claim and discuss some technical questions that arise if we allow descending grounding chains of transfinite length. (shrink)

A purely metaphysical formulation of physicalism is surprisingly elusive. One popular slogan is, 'There is nothing over and above the physical'. Problems with this arise on two fronts. First, it is difficult to explain what makes a property 'physical' without appealing to the methodology of physics or to particular ways in which properties are known. This obviously introduces epistemic features into the core of a metaphysical issue. Second, it is difficult to cash out 'over-and-aboveness' in a way that is rigorous, (...) metaphysically pure and extensionally apt for the purposes of the debate. In this paper I will touch on the first problem, but I wish to focus on the second. In particular, I will focus on the claim that supervenience theses cannot define physicalism because they allow classical emergentist dualism through the physicalist door [Horgan 1993; Kim 1998; Wilson 2005]. I will argue that when the relevant supervenience thesis is metaphysical, emergentism is excluded. Against recent arguments to the contrary, I maintain that this is the case even given necessitarianism about natural laws [Wilson 2005]. I will argue that a necessitarian with emergentist sympathies will be forced either into a type of quasi-panpsychism, where our basic physical properties contain the illicit seeds of mentality at their core, or she will be forced to admit that emergence laws are not necessary after all. Either way, the combination of necessitarianism and emergentism does not provide a counterexample to supervenience physicalism. (shrink)

On the truthmaker view of ontological commitment [Heil (From an ontological point of view, 2003); Armstrong (Truth and truthmakers, 2004); Cameron (Philosophical Studies, 2008)], a theory is committed to the entities needed in the world for the theory to be made true. I argue that this view puts truthmaking to the wrong task. None of the leading accounts of truthmaking—via necessitation, supervenience, or grounding—can provide a viable measure of ontological commitment. But the grounding account does provide a needed constraint on (...) what is fundamental. So I conclude that truthmaker commitments are not a rival to quantifier commitments, but a needed complement. The quantifier commitments are what a theory says exists, while the truthmaker commitments are what a theory says is fundamental. (shrink)

According to the zombie conceivability argument, phenomenal zombies are conceivable, and hence possible, and hence physicalism is false. Critics of the conceivability argument have responded by denying either that zombies are conceivable or that they are possible. Much of the controversy hinges on how to establish and understand what is conceivable, what is possible, and the link between the two—matters that are at least as obscure and controversial as whether consciousness is physical. Because of this, the debate over physicalism is (...) unlikely to be resolved by thinking about zombies—or at least, zombies as discussed by philosophers to date.



In this paper, I explore an alternative strategy against the zombie conceivability argument. I accept the possibility of zombies and ask whether that possibility is accessible (in the sense of ‘accessible’ used in possible world semantics) to our world. It turns out that the question of whether zombie worlds are accessible to our world is equivalent to the question of whether physicalism is true. By assuming that zombie worlds are accessible to our world, supporters of the zombie conceivability argument beg the question against physicalists. I will then consider what happens if a supporter of the zombie conceivability argument should insist that zombie worlds are accessible to our world. I will argue that the same ingredients used in the zombie conceivability argument—whatever they might be—can be used to construct an argument to the opposite conclusion. If that is correct, we reach a stalemate between physicalism and property dualism: while the possibility of some zombies entails property dualism, the possibility of other creatures entails physicalism. Since these two possibilities are inconsistent, one of them is not genuine. To resolve this stalemate, we need more than thought experiments. (shrink)

I think that there is an awful lot wrong with the exclusion problem. So, it seems, does just about everybody else. But of course everyone disagrees about exactly _what_ is wrong with it, and I think there is more to be said about that. So I propose to say a few more words about why the exclusion problem is not really a problem after all—at least, not for the nonreductive physicalist. The genuine _dualist_ is still in trouble. Indeed, one of (...) my main points will be that the nonreductive physicalist is in a rather different position vis à vis the exclusion problem than the dualist is. Properly understanding nonreductive physicalism—and clearly recognizing that it is, after all, a form of _physicalism_—goes a long way toward solving the exclusion problem. (shrink)

Physicalism is the thesis that everything is physical, or as contemporary philosophers sometimes put it, that everything supervenes on, or is necessitated by, the physical. The thesis is usually intended as a metaphysical thesis, parallel to the thesis attributed to the ancient Greek philosopher Thales, that everything is water, or the idealism of the 18th Century philosopher Berkeley, that everything is mental. The general idea is that the nature of the actual world (i.e. the universe and everything in it) conforms (...) to a certain condition, the condition of being physical. Of course, physicalists don't deny that the world might contain many items that at first glance don't seem physical — items of a biological, or psychological, or moral, or social nature. But they insist nevertheless that at the end of the day such items are either physical or supervene on the physical. (shrink)

Do grounding claims entail corresponding supervenience claims? The question matters, as a positive answer would help grounding theorists address worries that their hyperintensional primitive is obscure, and also increase the argumentative strategies that are available within ground-theoretic frameworks for metaphysical inquiry. Leuenberger (Erkenntnis 79:227–240, 2014a) argues for a negative response, by specifying some candidate principles of entailment and then claiming that each of them is subject to counterexamples. In this paper, I critically assess those principles and the objections he raises (...) against them, and advocate a novel entailment principle that overcomes all the problems suffered by those other principles. The principle I defend places a supervenience-based constraint on grounding claims, and secures a substantive connection between grounding and modality, weaker than necessitation. (shrink)

The concept of supervenience and a regimented concept of grounding are often taken to provide rival explications of pre-theoretical concepts of dependence and determination. Friends of grounding typically point out that supervenience claims do not entail corresponding grounding claims. Every fact supervenes on itself, but is not grounded in itself, and the fact that a thing exists supervenes on the fact that its singleton exists, but is not grounded in it. Common lore has it, though, that grounding claims do entail (...) corresponding supervenience claims. In this article, I show that this assumption is problematic. On one way of understanding it, the corresponding supervenience claim is just an entailment claim under a different name. On another way of understanding it, the corresponding claim is a distinctive supervenience claim, but its specification gives rise to what I call the "reference type problem": to associate the classes of facts that are the relata of grounding with the types of facts that are the relata of supervenience. However it is understood, supervenience rules out prima facie possibilities: alien realizers, blockers, heterogeneous realizers, floaters, and heterogeneous blockers. Instead of being rival explications of one and the same pre-theoretical concept, grounding and supervenience may be complementary concepts capturing different aspects of determination and dependence. (shrink)

I argue that metaphysicians of mind have not done justice to the notion of accessibility between possible worlds. Once accessibility is given its due, physicalism must be reformulated and conceivability arguments must be reevaluated. To reach these conclusions, I explore a novel way of assessing the zombie conceivability argument. I accept that zombies are possible and ask whether that possibility is accessible from our world in the sense of ‘accessible’ used in possible world semantics. It turns out that the question (...) whether zombie worlds are accessible from our world is equivalent to the question whether physicalism is true at our world. By assuming that zombie worlds are accessible from our world, proponents of the zombie conceivability argument beg the question against physicalism. In other words, it is a mistake to assume that the metaphysical possibility of zombies entails that physicalism is false at our world. I will then consider what happens if a proponent of the zombie conceivability argument should insist that zombie worlds are accessible from our world. I will argue that the same ingredients used in the zombie conceivability argument—whatever exactly they might be—can be used to construct an argument to the opposite conclusion. At that point, we reach a stalemate between physicalism and property dualism: while the possibility of zombies entails property dualism, the possibility of other creatures entails physicalism. Since these two possibilities are mutually inconsistent, either one of them is not genuine or one of them is inaccessible from the actual world. To resolve this stalemate, we need more than traditional conceivability arguments. (shrink)

This book argues that a plausible account of emergence requires replacing the traditional assumption that what primarily exists are particular entities with generic processes. Traversing contemporary physics and issues of identity over time, it then proceeds to develop a metaphysical taxonomy of emergent entities and of the character of human life.

Perhaps all concrete phenomena obtain solely in virtue of physical phenomena. Even so, it seems that the world could have been otherwise. It seems that physicalism, if true, is contingently true. In fact, many believe that the actual truth of physicalism allows metaphysically possible worlds duplicating the actual world in all physical respects while containing immaterial extras, e.g. ghosts, spirits, or Cartesian souls, that no physicalist would believe actually exist. Here I focus on physicalism regarding mentality and argue that the (...) doctrine does not allow possible worlds that physically duplicate the actual world while differing mentally. By revealing what physicalism (regarding the mind) does not allow, this essay helps us get clear on what the view really amounts to and why it is contingent. (shrink)

The first part of this thesis articulates and defends the Subjectivist View of the Mental. According to this view, my mental states are essentially different from the mental states of everyone else, but the fact that they are is a subjective fact, rather than an objective one. Chapter 1 explains what it takes for a fact to be subjective, what kind of difference holds between my mental states and everyone else's mental states and what kind of intuitions lead me to (...) believe that there is such a difference. Chapter 2 defends the Subjectivist View of the Mental from objections and discusses some of its most significant implications. In the second part of the thesis, I explore the advantages that the Subjectivist View of the Mental offers when it comes to accounting for three basic features of our knowledge of the mental. Chapter 3 deals with the asymmetry between self-knowledge and knowledge of other minds. It is argued that, if the Subjectivist View of the Mental is true, we can explain why this asymmetry holds without assuming that self-knowledge and knowledge of other minds are involved with substantially different ways of knowing. Chapter 4 focuses on the immunity to error through misidentification of mental self-ascriptions. I show that, while there has been a temptation to explain this phenomenon by following Lichtenberg and Wittgenstein in taking the content of mental self-ascriptions to be general rather than particular, this proposal cannot be made to work unless something like the Subjectivist View of the Mental is true. Chapter 5 is concerned with experiential knowledge. I argue that, if experiential truths are taken to be objective truths, it is not easy to see why experiential knowledge should have the peculiar 'first-hand' character it has. The problem disappears if experiential truths are regarded as subjective rather than objective. (shrink)

What has become known asthe blockers problemis an alleged difficulty facing attempts to formulate physicalism as a supervenience thesis. A blocker is an entity, itself contrary to physicalism, with the power to disrupt an otherwise necessary connection between physical and nonphysical conditions. I argue that there is no distinct blockers problem. Insofar as a problem can be identified, it turns out to be just a rather baroque version of a distinct and familiar objection to supervenience formulations and to be of (...) no independent interest. Work on the formulation of physicalism can thus proceed without worrying about blockers. (shrink)

A prominent objection to supervenience physicalism is that a definition of physicalism in terms of supervenience allows for physicalism to be compatible with nonphysicalist outlooks, such as certain forms of emergentism. I take as my starting point a recent defense of supervenience physicalism from this objection. According to this line of thought, the subvenient base for emergent properties cannot be said to be purely physical; rather, it is “polluted” with emergent features in virtue of necessarily giving rise to them. Thus, (...) if emergentism is true, it is false that everything supervenes on physical properties. I argue that this gives way to a new challenge for supervenience physicalism. The challenge, roughly, is to distinguish the emergentist’s “polluted” base from a physical supervenience base; that is, to give conditions under which the subvenient base is not “polluted” by supervenient properties. The problem, I argue, is that it is hard to see how this can be done without collapsing supervenience physicalism into alternative approaches to physicalism. I thus argue that if the present defense of supervenience physicalism succeeds in defending the adequacy of a supervenience-based definition of physicalism, it does so by compromising its uniqueness. (shrink)

Human freedom is often characterised as a unique power of self-determination. Accordingly, free human action is often thought to be determined by the agent in some distinctive manner. What is more, this determination is widely assumed to be a kind of efficient-causal determination. In reaction to this efficient-causal-deterministic conception of free human action, this paper argues that if one takes up the understanding of determination and causality that is offered by Anscombe in ‘Causality and Determination’, and moreover takes up an (...) understanding of free human action that is constrained by Anscombe’s account of intentional action in Intention, then an account of free human action as distinctively caused or determined by the agent is untenable. However, the notion of necessitation that Anscombe presents in ‘Causality and Determination’, which implies neither causality nor determination, offers an attractive alternative account. This alternative account pushes us to reconsider the sense in which human freedom is a power of self-determination, and to acknowledge the limits of our control in free action. (shrink)

Recently, several philosophers have argued that nonreductive physicalism is a false, unstable, and incoherent position. I argue that the position these critics are attacking is a straw one. To help explain why let us distinguish three issues about which nonreductive physicalists might plausibly be thought to have an opinion: ontological considerations about the types of things that exist at a world, issues involving the existence and nature of any dependency relationships between the types of things that exist at a world, (...) and epistemological questions regarding the best way to describe, explain, or characterize the types of things that exist at a world. I argue that reductive and nonreductive physicalists essentially agree with respect to the first two issues, but disagree with respect to the last issue. Nonreductive physicalists advocate a position that is ontologically or metaphysically reductive, but epistemologically or representationally nonreductive. Although this position could prove false on empirical grounds, it is neither unstable nor incoherent. (shrink)