Zombies are unconscious objects with conscious physical micro-duplicates. If zombies are possible then physicalism is false. It has been argued that zombies are possible if conceivable for an agent with ideal rationality. At any rate, they are possible only if so conceivable. This essay uses a mereological constraint to highlight the fine-grained differences between actually conscious physical objects and certain of their actually consciousness-incapable proper parts. These mereological considerations form the basis of an argument by dilemma that zombies are inconceivable. (...) Either an arbitrary actually conscious object might have had simpler consciousness-capable parts than it in fact has, or not. The affirmative horn leads to a version of panpsychism that is inconsistent with the ideal conceivability of zombies. The negative horn rules out zombies as incoherent. The upshot is a new reason to deny the conceivability of zombies. (shrink)

This paper examines the legitimacy of two common methodologies within philosophy: thought experiments and conceptual analysis. In particular, I examine the uses to which these two methodologies have been put within modal epistemology. I argue that, although both methods can be used to reveal conditional essentialist claims (e.g. necessarily: if x is water, then x is H20), neither can be used to reveal the de re essentialists claims (e.g. x is water and x is essentially H20) they’re often taken to (...) reveal. (shrink)

The paper argues against Peacocke's moderate rationalism in modality. In the first part, I show, by identifying an argumentative gap in its epistemology, that Peacocke's account has not met the Integration Challenge. I then argue that we should modify the account's metaphysics of modal concepts in order to avoid implausible consequences with regards to their possession conditions. This modification generates no extra explanatory gap. Yet, once the minimal modification that avoids those implausible consequences is made, the resulting account cannot support (...) Peacocke's moderate rationalism. (shrink)

The paper presents a dilemma for both epistemic and non-epistemic versions of conceivability-based accounts of modal knowledge. On the one horn, non-epistemic accounts do not elucidate the essentialist knowledge they would be committed to. On the other, epistemic accounts do not elucidate everyday life de re modal knowledge. In neither case, therefore, do conceivability accounts elucidate de re modal knowledge.

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)

The notion of conceivability has traditionally been regarded as crucial to an account of modal knowledge. Despite its importance to modal epistemology, there is no received explication of conceivability. In recent discussions, some have attempted to explicate the notion in terms of epistemic possibility. There are, however, two notions of epistemic possibility, a more familiar one and a novel one. I argue that these two notions are independent of one another. Both are irrelevant to an account of modal knowledge on (...) the predominant view of modal reality. Only the novel notion is relevant and apt on the competing view of modal reality; but this latter view is problematic in light of compelling counterexamples. Insufficient care regarding the independent notions of epistemic possibility can lead to two problems: a gross problem of conflation and a more subtle problem of obscuring a crucial fact of modal epistemology. Either problem needlessly hampers efforts to develop an adequate account of modal knowledge. I conclude that the familiar notion of epistemic possibility should be eschewed in the context of modal epistemology. (shrink)

Philosophers often make exotic-sounding modal claims, such as: “A timeless world is impossible”, “The laws of physics could have been different from what they are”, “There could have been an additional phenomenal colour”. Otherwise popular empiricist modal epistemologies in the contemporary literature cannot account for whatever epistemic justification we might have for making such modal claims. Those who do not, as a result of this, endorse scepticism with respect to their epistemic status typically suggest that they can be justified but (...) have yet to develop some distinct, workable theory of how. That is, they endorse a form of non-uniformism about the epistemology of modality, according to which claims about philosophically interesting modal matters need to be justified differently from e.g. everyday or scientific modal claims, but they fail to provide any more detail. This article aims to fill this gap by outlining how such a non-uniformist view could be spelled out and what story about philosophically interesting modal justification it could contain. (shrink)

Several philosophers of science claim that scientific toy models afford knowledge of possibility, but answers to the question of why toy models can be expected to competently play this role are scarce. The main line of reply is that toy models support possibility claims insofar as they are credible. I raise a challenge for this credibility-thesis, drawing on a familiar problem for imagination-based modal epistemologies, and argue that it remains unanswered in the current literature. The credibility-thesis has a long way (...) to go if it is to account for the epistemic merits of toy models. (shrink)

I discuss several problems for Williamson’s counterfactual-theory of modal knowledge and argue that they have a common source, in that the theory neglects to elucidate the proper constraints on modal reasoning. Williamson puts forward an empirical hypothesis that rests on the role of counterfactual reasoning for modal knowledge. But he overlooks central questions of normative modal epistemology. In order for counterfactual reasoning to yield correct beliefs about modality, it needs to be suitably constrained. I argue that what is needed is, (...) specifically, information concerning the nature or essence of things. By integrating this information, essentialist deduction arguably provides a better account of our knowledge of modality. Furthermore, I argue that essences have distinctive causal and explanatory powers—indeed, essences are superexplanatory for how things are. Compared to Williamson’s counterfactual-theory, superexplanatory essentialism clarifies what the proper constraints on modal reasoning are, and why they have such a special status. (shrink)

This paper shows why qualia constitute a problem for any theory of mental phenomena. We use the term ‘qualia’ in reference to non-intentional features of mental states which are eminently qualitative, i.e. perceptions, emotions, moods and body sensations. These non-intentional features are usually described as intrinsic, ineffable, infallible, atomic, private, direct and irreducible to the physical. The paper also explains the absent qualia argument which is addressed as a critique to functionalism.

The idea that justified modal belief can be accounted for in terms of empirically justified, non-modal belief is enjoying increasing popularity in the epistemology of modality. One alleged reason to prefer modal empiricism over more traditional, rationalist modal epistemologies is that empiricism avoids the problem with the integration challenge that arise for rationalism, assuming that we want to be realists about modal metaphysics. In this paper, I argue that given two very reasonable constraints on what it means to meet the (...) integration challenge for modality, empiricism is currently at best on a par with, but potentially worse off than, rationalist alternatives, with respect to the integration challenge. (shrink)

Philosophers have always taken an interest not only in what is actually the case, but in what is necessarily the case and what could possibly be the case. These are questions of modality. Epistemologists of modality enquire into how we can know what is necessary and what is possible. This dissertation concerns the meta-epistemology of modality. It engages with the rules that govern construction and evaluation of theories in the epistemology of modality, by using modal empiricism – a form of (...) modal epistemology – as a running example. In particular, I investigate the assumption that it is important to be able to meet the integration challenge. Meeting the integration challenge is a source of serious difficulty for many approaches, but modal empiricism is supposed to do well in this respect. But I argue that once we have a better grasp of what the integration challenge is, it is not obvious that it presents no problem for modal empiricism. Moreover, even if modal empiricism could be said to be in a relatively good position with respect to integration, it comes at the cost of a forced choice between far-reaching partial modal scepticism and non-uniformism about the epistemology of modality. Non-uniformism is the view that more than one modal epistemology will be correct. While non-uniformism might not in itself be unpalatable, it must be defined and defended in a way which squares with the modal empiricist’s other commitment. I explore two ways of doing so, both involving a revised idea of the integration challenge and its role for the epistemology of modality. One involves a bifurcation of the integration challenge, and the other a restriction of the integration challenge’s relevance. Both ways are interesting, but neither is, as it turns out, a walk in the park. (shrink)

The dissertation is in the format of a collection of several academic texts, composed of a two-part presentation and three papers on the topic of conceivability and the epistemology of modality. The presentation is composed of, first, a general introduction to conceivability theses and objections and, second, a discussion of two cases. Following the presentation, Asger provides three papers. The first paper, Pretense and Conceivability: A reply to Roca-Royes, presents a problem and a dilemma for Roca-Royes’ Non-Standard Dilemma for conceivability-based (...) epistemologies of de re modality in which she concludes that conceivability cannot be the whole story of our de re modal knowledge. The second paper, Conceivability Externalized, proposes an externalist conceivability-based epistemology of possibility inspired by Stalnaker. The third paper, Inconceivability as a Guide to Impossibility, considers inconceivability as an epistemic guide to impossibility, aiming to explore and add support to the underexplored thesis that one can justify beliefs about the impossibility of P on the basis of the inconceivability of P. (shrink)

The paper explores the project of an ambitious modal epistemology that attempts to combine the a priori methods of Chalmers’ 2D semantics with Kripke’s modal metaphysics. I argue that such a project is not viable. The ambitious modal epistemology involves an inconsistent triad composed of (1) Modal Monism, (2) Two-Dimensionalism, and what I call (3) “Metaphysical Kripkeanism”. I present the three theses and show how only two of those can be true at a time. There is a fundamental incompatibility between (...) Chalmers’ Modal Rationalism and Kripke’s modal metaphysics. Specifically, Chalmers’ conceivability entails possibilities that a Kripkean rejects as genuinely metaphysical. However, three positive stances in modal epistemology emerge from the combinations that the triad allows. One of those offers a promising way forward for 2D modal epistemologies. But it comes with a cost, as it requires abandoning modal monism and reshaping the scope of what a priori conceivability can give us access to. (shrink)

In his ‘anti-zombie argument’, Keith Frankish turns the tables on ‘zombists’, forcing them to find an independent argument against the conceivability of anti-zombies. I argue that zombists can shoulder the burden, for there is an important asymmetry between the conceivability of zombies and the conceivability of anti-zombies, which is reflected in the embedding of a totality-clause under the conceivability operator. This makes the anti-zombie argument susceptible to what I call the ‘Modified Incompleteness’, according to which we cannot conceive of scenarios. (...) In this paper I also argue that conceiving of the zombie-situation is a good starting point for rendering the zombie argument plausible. (shrink)

One powerful argument for dualism is provided by Chalmers: the ‘zombie’ or conceivability argument. This paper aims to establish that if one adopts the ‘Powerful Qualities’ account of properties developed by Martin and Heil, this argument can be resisted at the first premise: the claim that zombies are conceivable is, by the lights of Chalmers’ own account of conceivability, false. The Powerful Qualities account is outlined. Chalmers’ argument, and several distinctions which underlie it, are explained. It is argued that to (...) make sense of the claim that zombies are conceivable, some account of properties must be given. The paper’s central claim is presented and defended from potential responses: given the Powerful Qualities view, zombies are in fact inconceivable. Finally, an error theory is presented, which offers an explanation of why so many have taken the conceivability of zombies to be unproblematic, and the view is briefly contrasted with Russellian monism. (shrink)

This paper scrutinises the limits of a posteriori induction in acquiring modal knowledge. I focus on my similarity-based account (Roca-Royes [2017]); an inductive, non-rationalist epistemology of modality about concrete entities. Despite the explanatory merits of the account in relation to a vast range of modal claims, this inductive epistemology has been found incapable of yielding knowledge of a certain, other range of modal claims. Here, two notions of knowability are distinguished which reveal some of these limitations to be not only (...) accidental to the method but also virtuous. Additionally, the scrutiny suggests a recipe for increasingly pushing back, as modal enquirers, some of these limits. Limits will irremediably remain. But, as modal epistemologists, it is to explain what lies beyond these irremediable limits (not within) that we should look somewhere else. (shrink)

Howell Pacific Philosophical Quarterly, 89, 348–358 and Mizrahi and Morrow Ratio, 28, 1–13 offer a group of reductio arguments to rebut the CP thesis, i.e., the hypothesis that ideal conceivability entails possibility. Each of them has a conceivability premise: it is ideally conceivable that CP is false. According to the same CP, one can infer that CP’s being false is possible, from which it follows that CP is false. In other words, CP is shown to be self-defeating and therefore false (...) if any of these reductio arguments is proved sound. In this paper, I aim to disprove these arguments. I first show that neither Howell nor Mizrahi & Morrow provide adequate justification for their conceivability premises. I go on to argue that these reductio arguments face a dilemma: either their conceivability premises cannot be adequately justified, or they are redundant. Finally, I argue that, although this dilemma resists the reductio arguments against CP, on the other hand, it also reveals that CP lacks epistemic fruitfulness: it is of no practical use in the realm of apriority as well as necessity. (shrink)

David Chalmers supports his contention that there is a possible world populated by our zombie twins by arguing for the assumption that conceivability entails possibility. But, I argue, the modal epistemology he sets forth, ‘modal rationalism,’ ignores the problem of incompleteness and relies on an idealized notion of conceivability. As a consequence, this epistemology can’t justify our quotidian judgments of possibility, let alone those judgments that concern the mind/body connection. Working from the analogy that the imagination is to the possible (...) as perception is to the actual, I set forth a competing epistemology, ‘modal empiricism.’ This epistemology survives the incompleteness objection and allows some of our everyday modal judgments to be justified. But this epistemology can’t justify the claim that Zombie World is possible, which leaves Chalmers’s property dualism without the support it needs. (shrink)

A zombie world is a possible world in which all the microphysical truths are identical to the truths in our world, but no one is phenomenally conscious. A zombie is an individual in a possible world whose microphysical truths are identical to the microphysical truths of an individual in our world, but who has none of the phenomenal conscious experiences of the individual in our world. An inverted is an individual in a possible world whose microphysical truths are not only (...) identical to the microphysical truths of an individual in our world, but who also has phenomenal conscious experiences. These experiences, however, are qualitatively different from the ones of the individual in our world. The first premise of Chalmers’ conceivability argument against materialism is that a zombie world, a zombie and an inverted are ideally conceivable. This paper rejects this premise in claiming that: given that current physics does not allow philosophers to establish a clear concept of the physical that could be opposed to something else non-physical, a zombie world, a zombie and an inverted are merely prima facie, but not ideally conceivable. This objection is called the Obscurity of the Physical Objection.Key-words: Zombies, qualia, conceivability, possibility, physics. (shrink)

Some hold that if we can imagine God creating a world in which a particular proposition (p) is true, then we can conclude that p is possible. I argue that such appeals to God can’t provide us with a guide to possibility. For either God’s powers aren’t co-extensive with the possible or they are. And if they are, these appeals either beg the question or court a version of Euthyphro’s Dilemma. Some may argue that such appeals were only intended to (...) prompt us to think broadly about the modal claim at issue. I argue instead that these appeals must be understood as more than mere prompts. For it is these appeals that would, if successful, render the conceivability principle viable. (shrink)

The idea that justified modal belief can be accounted for in terms of empirically justified, non-modal belief is enjoying increasing popularity in the epistemology of modality. One alleged reason to prefer modal empiricism over more traditional, rationalist modal epistemologies is that empiricism avoids the problem with the integration challenge that arise for rationalism, assuming that we want to be realists about modal metaphysics. In this paper, I argue that given two very reasonable constraints on what it means to meet the (...) integration challenge for modality, empiricism is currently at best on a par with, but potentially worse off than, rationalist alternatives, with respect to the integration challenge. (shrink)

Resumen: El presente escrito argumenta cómo el denominado abuso de lo necesario a posteriori, propuesto en Beebee y Sabbarton-Leary, asume erróneamente que: a) los enunciados necesarios a posteriori requieren un compromiso metafísico con un esencialismo no trivial; y b) que el experimento mental de la tierra gemela cumple un rol evidencial en la determinación de lo necesario a posteriori. Contra a), se sostiene que lo necesario a posteriori no requiere un compromiso esencialista no trivial; a lo sumo, el esencialismo no (...) trivial es consecuencia de la propuesta de lo necesario a posteriori. Contra b), se afirma cómo el experimento mental de la tierra gemela cumple un rol subsidiario, explicativo y no evidencial. Esto evita un compromiso ontológico con el nexo concebible - posible. Luego, se discute cómo la noción de co- referencialidad rígida es una vía de solución a la exigencia de esencialismo no trivial. Finalmente, se considera de qué modo el esencialismo científico de Brian Ellis, al enunciar condiciones a priori de satisfacción, no afecta la justificación de lo necesario a posteriori. Del mismo modo, se defiende un nexo término rígido de jure/clase sustancial - término rígido de facto/clase propiedad.: This paper discusses how the so-called "abuse of the necessary a posteriori", proposed by Beebee and Sabbarton-Leary, erroneously assumes that: a) necessary a posteriori statements require a metaphysical commitment to a non-trivial essentialism, and b) the thought experiment of the twin earth fulfills an evidential role in determining the necessary a posteriori. Against a), it is argued that the necessary a posteriori does not require a non-trivial essentialist commitment; at most, nontrivial essentialism is a consequence of the necessary a posteriori. Contra b), it is stated how the thought experiment of the twin earth fulfills a subsidiary, explanatory, and non-evidential role. This prevents an ontological commitment to the conceivable-possible connection. It is then discussed how the notion of rigid coreferentiality is a way of solving the non-trivial essentialism requirement. Finally, we consider how Brian Ellis' scientific essentialism, in stating a priori conditions of satisfaction, does not affect the necessary a posteriori justification. (shrink)

Philosophers have conjectured that human cognitive limitations might preclude our ever resolving the hard problem of consciousness. Few, however, have offered suggestions as to what it might be about our conceptual apparatus that poses the problem. I do so in this essay, arguing that our central difficulties lie with two conceptual categories that pervade philosophical discussion of the hard problem. They are compositional concepts -- part/whole, constituents/constitution, and the like – and instantiational concepts: properties/objects, universals/particulars, and the like. I look (...) at the uses of these two conceptual categories in four contexts in which the hard problem is considered: multiple realizability, zombies, mental causation, and panpsychism. I show that the two conceptual categories run into the same kinds of obstacles in each case, which suggests that they might be key to the cognitive limitations about which some have speculated. (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)

RÉSUMÉ: Cette étude examine la relation entre la demande que les zombies sont logiquement/métaphysiquement possible et de la position que la conscience phénoménal est epiphenomenal. Il est souvent présumé que la première entraîne ce dernier, et que, par conséquent, toute implausibility dans la notion de conscience epiphenomenalism remet en question la possibilité réelle de zombies. Quatre façons dont les zombist pourrait répondre sont examinées, et je soutiens que les deux les plus fréquemment rencontrés sont insuffisantes, mais les autres—dont l’un est (...) rarement formulés et l’autre nouveaux—sont plus persuasif. Le résultat, cependant, est que le zombist pourraient en effet être confronté à un engagement indésirables à l’epiphenomenalism de conscience. (shrink)