Interactionists hold that minds are non-physical objects that interact with brains. The neural discernment problem for interactionism is that of explaining how non-physical minds produce behavior and cognition by exercising different causal powers over physiologically similar neurons. This paper sharpens the neural discernment problem and proposes two interactionist models of mind-brain interaction that solve it. One model avoids overdetermination while the other respects the causal closure of the physical domain.

This paper investigates ‘exterminous hypertime’, a model of time travel in which time travellers can change the past in virtue of there being two dimensions of time. This paper has three parts. Part one discusses the laws which might govern the connection between different ‘hypertimes’, showing that there are no problems with overdetermination. Part two examines a set of laws that mean changes to history take a period of hypertime to propagate through to the present. Those laws are of interest (...) because: (i) at such worlds, a particular problem for non-Ludovician time travel (‘the multiple time travellers’ problem) is avoided; and (ii) they allow us to make sense of certain fictional narratives. Part three discusses how to understand expectations and rational decision making in a world with two dimensions of time. I end with an appendix discussing how the different theories in the metaphysics of time (e.g., tensed/tenseless theories and presentism/eternalism/growing block theory) marry up with exterminous hypertime. (shrink)

Regardless of whatever else physicalism requires, nearly all philosophers agree that physicalism cannot be true in a world which contains fundamental mentality. I challenge this widely held attitude, and describe a world which is plausibly all-physical, yet which may contain fundamental mentality. This is a world in which priority monism is true—which is the view that the whole of the cosmos is fundamental, with dependence relations directed from the whole to the parts—and which contains only a single mental system, like (...) a brain or computer. Because some properties of the whole are fundamental under priority monism, it follows that that the mental properties of a cosmos-encompassing brain or computer system may be fundamental in a priority monist world. Yet such a world need not contain anything physically unacceptable: the mental properties of the cosmos-encompassing brain or computer can be characterized in a physicalism-friendly functionalist or identity-theoretic way. Thus, as I see it, physicalism need not be false in such a world. This constitutes a challenge to those who hold the view that physicalism is inconsistent with the existence of fundamental mentality. (shrink)

In this dissertation, I develop and defend a model of causation that allows for dualist mental causation in worlds where the physical domain is physically complete. In Part I, I present the dualist ontology that will be assumed throughout the thesis and identify two challenges for models of mental causation within such an ontology: the exclusion worry and the common cause worry. I also argue that a proper response to these challenges requires a thoroughly lightweight account of causation, i.e. an (...) account that allows for causes to be metaphysically distinct from the phenomena that produce or physically necessitate their effects. In Part II, I critically evaluate contemporary responses to these challenges from the philosophical literature. In particular, I discuss List and Stoljar’s criticism of exclusion worries, Kroedel’s alternative dualist ontology, concerns about the notion of causal sufficiency, and Lowe’s models of dualist mental causation. I argue that none of these proposals provide independent motivation for a thoroughly lightweight account of causation and therefore leave room for improvement. In the first four chapters of Part III, I develop a thoroughly lightweight model of causation, which builds on interventionist approaches to causation. First, I explain how so-called ‘holding fixed’-requirements in standard interventionist accounts stand in the way of dualist mental causation. I then argue that interventionist accounts should impose a robustness condition on causal correlations and that, with this condition in place, the ‘holding fixed’-requirements can be weakened such that they do allow for dualist mental causation. I dub the interventionist model with such weakened ‘holding fixed’-requirements ‘insensitive interventionism’, argue that it can counter the exclusion worry as well as the common cause worry, and explain under which circumstances it would predict there to be dualist mental causation. Importantly, these circumstances might, for all we know, hold in the actual world. In the final three chapters of Part III, I defend insensitive interventionism against some objections. I consider the objection that causation must be productive, the objection that causes must physically necessitate their effects, and the objection that insensitive interventionism is too permissive. I respond by drawing from the literature on causation by absences and on the relation between causation and fundamental physics. Overall, insensitive interventionism performs as well as standard interventionist accounts. I conclude that insensitive interventionism is a credible model of causation. (shrink)

Dualism holds that experiences somehow arise from physical states, despite being neither identical with nor grounded in such states. This paper motivates a stringent set of constraints on constructing a dualist theory of experience. To meet the constraints, a dualist theory must: (1) construe experiences as causes of physical effects, (2) ensure that experiences do not cause observable violations of the causal closure of the physical domain, (3) avoid overdetermination, (4) specify a set of psychophysical laws that yield experiences as (...) a function of physical states, and (5) ensure that functional duplication preserves phenomenology. After motivating these constraints and explaining why existing dualist theories satisfy only some of them, I construct a dualist theory that satisfies all of them. On the resulting theory—which I call delegatory dualism—experiences uphold causal responsibilities “delegated” to them by physical states. (shrink)

Colour primitivism is the thesis that the colours are simple qualitative properties of items in the external world—just as they appear to be. This paper considers colour primitivism in relation to a version of Frank Jackson’s knowledge argument. On the one hand, this argument seems to support primitivism, by delivering the conclusion that the colours cannot be reduced to underlying physical features of a sort that Mary might have known about even in the room. On the other hand, however, the (...) argument threatens to show that primitivism cannot be combined with even a fairly minimal (non-reductive) form of physicalism, on which the colours are conceived as supervenient upon or grounded in underlying physical properties. To resolve the tension, the paper recommends a novel primitivist take on the knowledge argument, which turns crucially on the classical empiricist thesis to the effect that certain facts about the colours can only be learned on the basis of sensory experience. (shrink)

Nonreductive physicalists endorse the principle of mental causation, according to which some events have mental causes: Sid climbs the hill because he wants to. Nonreductive physicalists also endorse the principle of physical causal completeness, according to which physical events have sufficient physical causes: Sid climbs the hill because a complex neural process in his brain triggered his climbing. Critics typically level the causal exclusion problem against this nonreductive physicalist model, according to which the physical cause is a sufficient cause of (...) the behavioural effect, so the mental cause is excluded from causally influencing Sid’s behaviour. In this paper I demonstrate how numerous nonreductive physicalists have responded to the causal exclusion problem by weakening the principle of physical causal completeness in numerous ways. The result: either numerous nonreductive physicalist solutions fail on account of the fact that they do not satisfy a robustly defined principle of physical causal completeness, or there is an accelerating trend of solving the causal exclusion problem by suitably weakening the principle of physical causal completeness. (shrink)

Peter Van Inwagen argues that The Principle of Sufficient Reason (PSR) either leads to contradiction or it leads to necessitarianism. Although I agree with Van Inwagen that the relationship between the PSR and necessitarianism is close, I argue that the PSR is compatible with innocent versions of necessitarianism. In this project my main argument is that modal realism can account for the PSR and integrate it within an innocent version of necessitarianism. My main claim will be that each fact in (...) each possible world is grounded in the principle of plenitude. Also, while each fact is grounded in plenitude, it avoids rigid necessitarianism because (i) actuality is not captured by the PSR, (ii) things could be otherwise because there are other worlds, and due to the principle of recombination (iii) cardinality of possible worlds is maximized and (iv) there are no necessary connections between distinct individuals. As a result, the relationship between modal realism and the PSR is symbiotic. Through modal realism, the PSR also results as: having its scope extended to the realm of all possibilia rather than being confined to mere actuality; it solves indeterminacy problems like Leibniz’s problem of space or the hard problem of consciousness; it accounts for facts in lawless worlds etc. On the other hand, through the PSR, modal realism gets one more benefit in its inventory because it accounts for the PSR. Thus, modal realism still continues on Lewis’ paradoxical path of proving to be highly pragmatic but counterintuitive at the same time. If added benefits are worth the costs for modal realism is still an open question. (shrink)

Compatibilists aim to solve the causal exclusion problem by arguing that a physical cause and a mental cause are compatible with each other without involving the problematic overdetermination. The purpose of this paper is twofold. First, I target at Karen Bennett’s (2003, 2008) influential compatibilist strategy—one that rests on the assumption that a mental cause is sufficient for bringing about a physical effect, just as a physical cause is. I argue that, on a plausible physicalist picture, this assumption cannot be (...) established. Second, I propose a weaker and more plausible interpretation of the mental efficacy, which takes a mental cause to be necessary (but not sufficient) for a physical effect in a counterfactual sense. The resulting picture of mental causation avoids the difficulties engendered from Bennett’s assumption and delivers fresh resources to solve the exclusion problem. (shrink)

This article argues that standard causal and functionalist definitions of realization fail to account for the realization of entities that cannot be individuated in causal or functional terms. By modifying such definitions to require that realizers also logically suffice for any historical properties of the entities they realize, one can provide for the realization of entities whose resistance to causal/functional individuation stems from their possession of individuative historical properties. But if qualia cannot be causally or functionally individuated, then qualia can (...) be physically realized only if the thesis that all things are physical or physically realized is insufficient for physicalism. (shrink)