Many philosophers accept the conceivability of zombies: creatures that lack consciousness but are physically and functionally identical to conscious human beings. Many also believe that the conceivability of zombies supports their metaphysical possibility. And most agree that if zombies are metaphysically possible, then physicalism is false. So, the claim that zombies are conceivable may have considerable significance.¹.

This paper proposes a new line of attack on the conceivability argument for mind-body property dualism, based on the causal account of properties, according to which properties have their conditional powers essentially. It is argued that the epistemic possibility of physical but not phenomenal duplicates of actuality is identical to a metaphysical (understood as broadly logical) possibility, but irrelevant for establishing the falsity of physicalism. The proposed attack is in many ways inspired by a standard, broadly Kripkean approach to epistemic (...) and metaphysical modality. (shrink)

Zombies, as conceived by philosophers these days, are supposed to be creatures that are physically indistinguishable from normal people that nevertheless completely lack phenomenal consciousness. The kind of zombie I want to focus on is one that is molecule- by-molecule identical to a healthy, normal, adult human being living in a world physically like ours — indeed this might be our own actual world. To make things more concrete, pick any such person that you actually know. Let this be John. (...) John is not a zombie. Now consider an exact, perfect, physical replica of John, call him Zhon. Note that because John and Zhon are physically alike, they are also behaviorally and functionally alike. So if you were to encounter Zhon, you could not distinguish him from John. Under the imagined circumstances so far, you would normally expect Zhon to be conscious as well. But let’s stipulate that Zhon has no conscious experiences whatsoever — he’s never had them, nor will he ever have them. So Zhon, according to this stipulation, doesn’t know — indeed cannot know — what it is like to have conscious experiences of any kind. There is nothing it is like to be Zhon. Zhon lacks conscious phenomenology altogether. If Zhon were to be a metaphysically possible creature, he would be a zombie.1 So this is the notion of zombie I would like to focus on. According to many philosophers, Zhon is a possible creature, and that is because Zhon is a conceivable creature. This gives us the argument from zombies against physicalism. Physicalism is the doctrine that says: all that exist is physical through and through, including conscious minds and their conscious experiences. The zombie argument, as we might call it, is a species of conceivability arguments: 1. If Zhon is conceivable, then Zhon is possible. 2. Zhon is conceivable. 3. Hence, Zhon is possible. Now since the choice of Zhon was arbitrary, we can, of course, generalize the argument to all zombies like Zhon — that is, to zombies that are physically indistinguishable, in relevant respects, to healthy, normal, adult human beings.. (shrink)

This essay is a sustained attempt to bring new light to some of the perennial problems in philosophy of mind surrounding phenomenal consciousness and introspection through developing an account of sensory and phenomenal concepts. Building on the information-theoretic framework of Dretske (1981), we present an informational psychosemantics as it applies to what we call sensory concepts, concepts that apply, roughly, to so-called secondary qualities of objects. We show that these concepts have a special informational character and semantic structure that closely (...) tie them to the brain states realizing conscious qualitative experiences. We then develop an account of introspection which exploits this special nature of sensory concepts. The result is a new class of concepts, which, following recent terminology, we call phenomenal concepts: these concepts refer to phenomenal experience itself and are the vehicles used in introspection. On our account, the connection between sensory and phenomenal concepts is very tight: it consists in different semantic uses of the same cognitive structures underlying the sensory concepts, such as the concept of red. Contrary to widespread opinion, we show that information theory contains all the resources to satisfy internalist intuitions about phenomenal consciousness, while not offending externalist ones. A consequence of this account is that it explains and predicts the so-called conceivability arguments against physicalism on the basis of the special nature of sensory and phenomenal concepts. Thus we not only show why physicalism is not threatened by such arguments, but also demonstrate its strength in virtue of its ability to predict and explain away such arguments in a principled way. However, we take the main contribution of this work to be what it provides in addition to a response to those conceivability arguments, namely, a substantive account of the interface between sensory and conceptual systems and the mechanisms of introspection as based on the special nature of the information flow between them. (shrink)

It is widely suspected that arguments from conceivability, at least in some of their more notorious instances, are unsound. However, the reasons for the failure of conceivability arguments are less well agreed upon, and it remains unclear how to distinguish between sound and unsound instances of the form. In this paper I provide an analysis of the form of arguments from conceivability, and use this analysis to diagnose a systematic weakness in the argument form which reveals all its instances to (...) be, roughly, either uninformative or unsound. I illustrate this conclusion through a consideration of David Chalmers. (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)

In this paper I begin to develop an account of the acquaintance that each of us has with our own conscious states and processes. The account is a speculative proposal about human mental architecture and specifically about the nature of the concepts via which we think in first personish ways about our qualia. In a certain sense my account is neutral between physicalist and dualist accounts of consciousness. As will be clear, a dualist could adopt the account I will offer (...) while maintaining that qualia themselves are non-physical properties. In this case the non-physical nature of qualia may play no role in accounting for the features of acquaintance. But although the account could be used by a dualist, its existence provides support for physicalism. (shrink)

During the last two decades, several different anti-physicalist arguments based on an epistemic or conceptual gap between the phenomenal and the physical have been proposed. The most promising physicalist line of defense in the face of these arguments – the Phenomenal Concept Strategy – is based on the idea that these epistemic and conceptual gaps can be explained by appeal to the nature of phenomenal concepts rather than the nature of non-physical phenomenal properties. Phenomenal concepts, on this proposal, involve unique (...) cognitive mechanisms, but none that could not be fully physically implemented. David Chalmers has recently presented a Master Argument to show that the Phenomenal Concept Strategy – not just this or that version of it, but any version of it – fails. Chalmers argues that the phenomenal concepts posited by such theories are either not physicalistically explicable, or they cannot explain our epistemic situation with regard to qualia. I argue that it is his Master Argument that fails. My claim is his argument does not provide any new reasons to reject the Phenomenal Concept Strategy. I also argue that, although the Phenomenal Concept Strategy is successful in showing that the physicalist is not rationally compelled to give up physicalism in the light of the anti-physicalist arguments, the anti-physicalist is not rationally compelled to give up the anti-physicalist argument in the light of the Phenomenal Concept Strategy either. (shrink)

This paper was chosen by The Philosopher’s Annual as one of the ten best articles appearing in print in 2000. Reprinted in Volume XXIII of The Philosopher’s Annual. In his very influential book David Chalmers argues that if physicalism is true then every positive truth is a priori entailed by the full physical description – this is called “the a priori entailment thesis – but ascriptions of phenomenal consciousness are not so entailed and he concludes that Physicalism is false. As (...) he puts it, “zombies” are metaphysically possible. I attempt to show (I think successfully) that this argument is refuted by considering an analogous argument in the mouth of a zombie. The conclusion of this argument is false so one of the premises is false. I argue at length that this shows that the original conceivability argument also has a false premise and so is invalid. -/- . (shrink)

In this paper I survey the landscape of anti-physicalist arguments and physicalist responses to them. The anti-physicalist arguments I discuss start from a premise about a conceptual, epistemic, or explanatory gap between physical and phenomenal descriptions and conclude from this – on a priori grounds – that physicalism is false. My primary aim is to develop a master argument to counter these arguments. With this master argument in place, it is apparent that there is a puzzling symmetry between dualist attacks (...) on physicalism and physicalist replies. Each position can be developed in a way to defend itself from attacks from the other position. Therefore the debate comes down to which metaphysical framework provides the better overall explanatory/theoretical framework. (shrink)

Hill and Levine offer alternative explanations of these conceivabilities, concluding that these conceivabilities are thereby defeated as evidence. However, this strategy fails because their explanations generalize to all conceivability judgments concerning phenomenal states. Consequently, one could defend absolutely any theory of phenomenal states against conceivability arguments in just this way. This result conflicts with too many of our common sense beliefs about the evidential value of conceivability with respect to phenomenal states. The general moral is that the application of such (...) principles of explanatory defeat is neither simple nor straightforward. (shrink)

In _The Conscious Mind: In Search of a Fundamental Theory_, David Chalmers poses an interesting and powerful challenge to materialism or physicalism. Further, he goes a long way towards providing a proof by example that the rejection of materialism need not commit one to scientifically suspicious “ghost in the machine” doctrines, but can be wedded to a generally naturalistic perspective. As an (as yet) unpersuaded physicalist and functionalist, his case against physicalism seems an appropriate target for criticism. However, it would (...) be beyond the scope of the present paper—or anything of similar length—to attempt a full-scale reply. A full-scale reply could be executed in brief compass only if Chalmers were guilty of (and rested his case entirely upon) some relatively simple mistake. But he does not. If he is mistaken, the mistakes are more subtle and difficult to bring to light. Instead, I shall outline the essentials of his case against materialism, attempt to point to one problem that appears to infect his views and argue that, if his position is to be acceptable, he needs to deal with it more adequately than he has so far. (shrink)

The paper begins with a clarification of the notions of intuition (and, in particular, modal intuition), modal error, conceivability, metaphysical possibility, and epistemic possibility. It is argued that two-dimensionalism is the wrong framework for modal epistemology and that a certain nonreductionist approach to the theory of concepts and propositions is required instead. Finally, there is an examination of moderate rationalism.

Scientific essentialism is the view that some necessities (e.g., water = H2O) can be known only with the aid of empirical science. The thesis of the paper is that scientific essentialism does not extend to the central questions of philosophy and that these questions can be answered a priori. The argument is that the evidence required for the defense of scientific essentialism (e.g., twin earth intuitions) is reliable only if the intuitions required by philosophy to answer its central questions is (...) also reliable. Included is an outline of a modal reliabilist theory of basic evidence and a concept-possession account of the reliability of a priori intuition. (shrink)

Case 1: Perhaps the phenomenal facts—facts about what it’s like to see red, or to taste freshly made pesto—do not supervene with metaphysical necessity on the physical facts and physical laws. This might be because the connections between the physical and the phenomenal are entirely unprincipled. Alternatively, it might be because whatever psychophysical laws do govern those connections are contingent. Either way, the claim is that there are metaphysically possible worlds that are just like the actual world in terms of (...) what physical laws hold, and in terms of the distribution of physical properties, but which are phenomenally different from the actual world. In some such worlds, different phenomenal facts obtain. In other such worlds, no phenomenal properties are instantiated at all. Call the latter sort of world a ‘phenomenal zombie world’, or, for short, just a ‘zombie world’. (shrink)

Is it true that if zombies-creatures who are behaviorally indistinguishable from us, but no more conscious than a rock-are logically possible, the computational conception of mind is false? Are zombies logically possible? Are they physically possible? This paper is a careful, sustained argument for affirmative answers to these three questions.

In this paper I argue that a priori arguments fail to present any real problem for physicalism. They beg the question against physicalism in the sense that the argument will only seem compelling if one is already assuming that qualitative properties are nonphysical. To show this I will present the reverse-zombie and reverse-knowledge arguments. The only evidence against physicalism is a priori arguments, but there are also a priori arguments against dualism of exactly the same variety. Each of these parity (...) arguments has premises that are just as intuitively plausible, and it cannot be the case that both the traditional scenarios and the reverse-scenarios are all ideally conceivable. Given this one set must be merely prima facie conceivable and only empirical methods will tell us which is which. So, by the time a priori methodology will be of any use it will be too late. <br>. (shrink)

This book covers a vast amount of material in the philosophy of mind, which makes it difficult to do justice to its tightly argued and nuanced details. It does, however, have two overarching goals that are visible, so to speak, from space. In the first half of the book Kirk aims to show that, contra his former self, philosophical zombies are not conceivable. By this he means that the zombie scenario as usually constructed contains an unnoticed contradiction, and explaining the (...) contradiction reveals a radical misconception about the nature of phenomenal <span class='Hi'>consciousness</span>. His second aim of the book is to construct a theory of perceptual-phenomenal <span class='Hi'>consciousness</span> that avoids this contradiction.            The anti-zombie argument can be stated rather easily. According to the ‘zombist’ there can be a creature that is a molecule-for-molecule-duplicate of me and yet lacks phenomenal <span class='Hi'>consciousness</span>. At the same time they want to hold that we have ‘epistemic access’ to our phenomenal <span class='Hi'>consciousness</span>. These two claims are not consistent with each other. To see why, imagine a zombie world that is identical to ours except in respect of phenomenal <span class='Hi'>consciousness</span>. Since that world is just like ours we can assume that it is causally closed under the physical. Now, continues Kirk, it should be possible to add to that world whatever it is that the zombist thinks will transform it into a world that does have phenomenal <span class='Hi'>consciousness</span>. But since whatever we added would have to be nonphysical, since their world is identical to ours (excepting <span class='Hi'>consciousness</span>), and so could not interact causally with the physical world (which is closed under the physical), it follows that we could not know anything about these ‘e-qualia’. Therefore, we could not have ‘epistemic access’ to them.            To make this vivid he offers what he calls the ‘sole-pictures’ argument. Again, consider our zombie world.. (shrink)

This book covers a vast amount of material in the philosophy of mind, which makes it difficult to do justice to its tightly argued and nuanced details. It does, however, have two overarching goals that are visible, so to speak, from space. In the first half of the book Kirk aims to show that, contra his former self, philosophical zombies are not conceivable. By this he means that the zombie scenario as usually constructed contains an unnoticed contradiction, and explaining the (...) contradiction reveals a radical misconception about the nature of phenomenal consciousness. His second aim of the book is to construct a theory of perceptual-phenomenal consciousness that avoids this contradiction. (shrink)

In The Conscious Mind, D. Chalmers appeals to his semantic framework in order to show that conceivability, as employed in his "zombie" argument for dualism, is sufficient for genuine possibility. I criticize this attempt.

Zombies are hypothetical creatures of the sort that philosophers have been known to cherish. A zombie is physically identical to a normal human being, but completely lacks conscious experience. Zombies look and behave like the conscious beings that we know and love, but "all is dark inside." There is nothing it is like to be a zombie.

What follows are compressed versions of three lectures on the subject of "Mind and Modality", given at Princeton University the week of October 12-16, 1998. The first two form a series; the third stands alone to some extent. All are philosophically technical, and probably of interest mainly to philosophers. I hope that they make sense, at least to those familiar with my book _The Conscious Mind_ . Lecture 1 recapitulates some of the material in the book in a somewhat different (...) form, and adds some further material on conditionals and on Kripke. Note that section has a more or less definitive formalization of the anti-materialist argument from the book (lots of people have asked for this). Lecture 2 pushes deeper into the heart of modality, further investigating the conceivability/possibility relationship and the epistemology of modality (with some material on the scrutability of truth in general), and arguing for a sort of modal rationalism. Lecture 3 gives an analysis of the content of beliefs about experiences, and applies this to a number of epistemological issues, including incorrigibility and the dialectic on "The Myth of the Given". (shrink)

A number of popular arguments for dualism start from a premise about an epistemic gap between physical truths about truths about consciousness, and infer an ontological gap between physical processes and consciousness. Arguments of this sort include the conceivability argument, the knowledge argument, the explanatory-gap argument, and the property dualism argument. Such arguments are often resisted on the grounds that epistemic premises do not entail ontological conclusion. My view is that one can legitimately infer ontological conclusions from epistemic premises, if (...) one is very careful about how one reasons. To do so, the best way is to reason first from epistemic premises to modal conclusions (about necessity and possibility), and from there to ontological conclusions. Here, the crucial issue is the link between the epistemic and modal domains. How can one reason from theses about what is knowable or conceivable to theses about what is necessary or possible? To bridge the epistemic and modal domains, the framework of two-dimensional semantics can play a central role. I have used this framework in earlier work (Chalmers 1996) to mount an argument against materialism. Here, I want to revisit the argument, laying it out in a more explicit and careful form, and responding to a number of objections. In what follows I will concentrate mostly on the conceivability argument. I think that very similar considerations apply to the other arguments mentioned above, however. In the final section of the paper, I show how this analysis might yield a unified treatment of a number of anti-materialist arguments. (shrink)

John Perry's book Knowledge, Possibility, and Consciousness is a lucid and engaging defense of a physicalist view of consciousness against various anti-physicalist arguments. In what follows, I will address Perry's responses to the three main anti-physicalist arguments he discusses: the zombie argument (focusing on imagination), the knowledge argument (focusing on indexicals), and the modal argument (focusing on intensions).

There is a long tradition in philosophy of using a priori methods to draw conclusions about what is possible and what is necessary, and often in turn to draw conclusions about matters of substantive metaphysics. Arguments like this typically have three steps: first an epistemic claim (about what can be known or conceived), from there to a modal claim (about what is possible or necessary), and from there to a metaphysical claim (about the nature of things in the world).

This appeared in Philosophy and Phenomenological Research 59:473-93, as a response to four papers in a symposium on my book The Conscious Mind . Most of it should be comprehensible without having read the papers in question. This paper is for an audience of philosophers and so is relatively technical. It will probably also help to have read some of the book. (There is a corresponding precis of the book, written for the symposium.) The papers I'm responding to are: Chris (...) Hill & Brian McLaughlin, There are fewer things in reality than are dreamt of in Chalmers' philosophy Brian Loar, David Chalmers' The Conscious Mind Sydney Shoemaker, On David Chalmers' The Conscious Mind Stephen Yablo, Concepts and consciousness Contents. (shrink)

In Section 5 of his interesting article, Goldman suggests that the consideration of imaginary cases can be valuable in the analysis of our psychological concepts. In particular, he argues that we can imagine a system that is isomorphic to us under any functional description, but which lacks qualitative mental states, such as pains and color sensations. Whether or not such a being is empirically possible, it certainly seems to be logically possible, or conceptually coherent. Goldman argues from this possibility to (...) the conclusion that our concepts of qualitative mental states cannot be analyzed entirely in functional terms. (shrink)

               Here is one good way of looking at the problem of consciousness: (Saul Steinberg’s New Yorker cover). If this is the metaphorical truth about consciousness, what is the literal truth? What is going on in the world, (largely in this chap’s brain, presumably) that makes it the case that this gorgeous metaphor is so apt?

Knock-down refutations are rare in philosophy, and unambiguous self-refutations are even rarer, for obvious reasons, but sometimes we get lucky. Sometimes philosophers clutch an insupportable hypothesis to their bosoms and run headlong over the cliff edge. Then, like cartoon characters, they hang there in mid-air, until they notice what they have done and gravity takes over. Just such a boon is the philosophers' concept of a zombie, a strangely attractive notion that sums up, in one leaden lump, almost everything that (...) I think is wrong with current thinking about consciousness. Philosophers ought to have dropped the zombie like a hot potato, but since they persist in their embrace, this gives me a golden opportunity to focus attention on the most seductive error in current thinking. (shrink)

The inference from conceivability to possibility has been challenged in numerous ways. One of these ways is the so-called phenomenal concept strategy, which has become one of the main strategies against the conceivability argument against physicalism. However, David Chalmers has recently presented a dilemma for the phenomenal concept strategy, and he has argued that no version of the strategy can succeed. In this paper, I examine the dilemma, and I argue that there is a way out of it. I conclude (...) that Chalmers has not posed any serious problem for the phenomenal concept strategy to succeed in blocking the conceivability argument. In doing so, my aim is not only to show that Chalmers’s argument has not refuted the phenomenal concept strategy, but also to clarify what any version of the strategy should achieve in order to be successful. (shrink)

One of the main strategies against conceivability arguments is the so-called phenomenal concept strategy, which aims to explain the epistemic gap between physical and phenomenal truths in terms of the special features of phenomenal concepts. Daniel Stoljar has recently argued that the phenomenal concept strategy has failed to provide a successful explanation of this epistemic gap. In this paper my aim is to defend the phenomenal concept strategy from his criticisms. I argue that Stoljar has misrepresented the resources of the (...) strategy, which can indeed accomplish the required explanatory task, once it is properly understood. (shrink)

The phenomenal concept strategy is one of the most attractive responses to the so-called conceivability arguments. A crucial step in these arguments is the inference from conceivability to possibility. The phenomenal concept strategy attacks this inference from conceivability to possibility: they argue that there is an alternative explanation of the conceivability of zombies, which does not involve the possibility of zombies. This alternative explanation appeals to special features of phenomenal concepts in order to explain the conceivability of zombies. Daniel Stoljar (...) has recently argued that if the phenomenal concept strategy was a good strategy against the conceivability argument against physicalism, it would also be a good strategy against the conceivability argument against behaviourism. But he claims that the latter conceivability argument is sound, and therefore the phenomenal concept strategy cannot be correct. In this paper I show how the phenomenal concept strategy can respond to this objection. (shrink)

Chalmers' anti-materialist arguments are an interesting twist on a well-known argument form, and his naturalistic dualism is exciting to contemplate. Nevertheless, we think we can save materialism from the Chalmerian attack. This is what we do in the present paper.

Beginning with the paradoxes of zombie twins, we present an argument that dualism is both true and false. We show that avoiding this contradiction is impossible. Our diagnosis is that consciousness itself engenders this contradiction by producing contradictory points of view. This result has a large effect on the realism/anti-realism debate, namely, it suggests that this debate is intractable, and furthermore, it explains why this debate is intractable. We close with some comments on what our results mean for metaphysics and (...) philosophy, in general. (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 (and the very term ‘epistemic possibility’) should be eschewed in the context of modal epistemology. (shrink)

In recent years the 'zombie argument' has come to occupy a central role in the case against physicalist views of consciousness, in large part because of the powerful advocacy it has received from David Chalmers.1 In this paper I seek to neutralize it by showing that a parallel argument can be run for physicalism, an argument turning on the conceivability of what I shall call anti-zombies. I shall argue that the result is a stand-off, and that the zombie argument offers (...) no independent reason to reject physicalism. (shrink)

This paper advances the thesis that we can justifiably believe philosophically interesting possibility statements. The first part of the paper critically discusses van Inwagens skeptical arguments while at the same time laying some of the foundation for a positive view. The second part of the paper advances a view of conceivability in terms of imaginability, where imaginging can be propositional, pictorial, or a combination of the two, and argues that conceivability can, and often does, provide us with justified beliefs of (...) what is metaphysically possible. The notion of scenarios is developed, as is an account of how filling out scenarios can uncover a defeater or, in many cases, strengthen the justification for the relevant possibility statement. (shrink)

The capacity to represent things to ourselves as possible plays a crucial role both in everyday thinking and in philosophical reasoning; this volume offers much-needed philosophical illumination of conceivability, possibility, and the relations between them.

To what extent and how is conceivability a guide to possibility? This essay explores general philosophical issues raised by this question, and critically surveys responses to it by Descartes, Hume, Kripke and "two-dimensionalists.".

My aim here is threefold: (a) to show that conceptual facts play a more significant role in justifying explanatory reductions than most of the contributors to the current debate realize; (b) to furnish an account of that role, and (c) to trace the consequences of this account for conceivability arguments about the mind.

Zombies are bodies without minds: creatures that are physically identical to actual human beings, but which have no conscious experience. Much of the consciousness literature focuses on considering how threatening philosophical reflection on such creatures is to physicalism. There is not much attention given to the converse possibility, the possibility of minds without bodies, that is, creatures who are conscious but whose nature is exhausted by their being conscious. We can call such a ‘purely conscious’ creature a ghost.

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 robot that is functionally indistinguishable from us may or may not be a mindless Zombie. There will never be any way to know, yet its functional principles will be as close as we can ever get to explaining the mind.

A robot that is functionally indistinguishable from us may or may not be a mindless Zombie. There will never be any way to know, yet its functional principles will be as close as we can ever get to explaining the mind.

Zombies recently conjured by Searle and others threaten civilized (i.e., materialistic) philosophy of mind and scientific psychology as we know it. Humanoid beings that behave like us and may share our functional organizations and even, perhaps, our neurophysiological makeups without qualetative conscious experiences, zombies seem to meet every materialist condition for thought on offer and yet -- the wonted intuitions go -- are still disqualefied (disqualified for lack of qualia) from being thinking things. I have a plan. Other zombies -- (...) good (qualia eating) zombies -- can battle their evil (behavior eating) cousins to a standoff. Perhaps even defeat them. Familiar zombies and supersmart zombies resist disqualefication, making the world safe, again, for materialism. Behavioristic materialism. Alas for functionalism, good zombies still eat programs. Alas for identity theory, all zombies -- every B movie fan knows -- eat brains. (shrink)

Certain cognitive and philosophical aspects of the concept of conceivability with intended or established diversion from (putative) reality are discussed. The “coherence gap problem” arises when certain fragments of the real world are replaced with imaginary situations while most details are (intentionally or not) ignored. Another issue, “the spectator problem”, concerns the participation of the conceiver himself in the world conceived. Three different examples of conceivability are used to illustrate our points, namely thought experiments in physics, a hypothetical world devoid (...) of consciousness (zombie world), and virtual reality. (shrink)

This paper engages with two compelling challenges to physicalism, each designed to show that the nature of experience is elusive from the standpoint of physical science. It is argued that the physicalist is ultimately well placed to meet both challenges.

This paper suggests a critique of the zombie argument that bypasses the need to decide on the truth of its main premises, and specifically, avoids the need to enter the battlefield of whether conceivability entails metaphysical possibility. It is argued that if we accept, as the zombie argument’s supporters would urge us, the assumption that an ideal reasoner can conceive of a complete physical description of the world without conceiving of qualia, the general principle that conceivability entails metaphysical possibility, and (...) the general principle that for any s and t the metaphysical possibility of s & − t entails that s does not necessitate t, we have to conclude not that materialism is false but rather that either materialism or the “mental paint” (or “phenomenist”) conception of phenomenality is false. And further, given the initial advantages of materialism, the fact that proponents of the zombie argument are not allowed to rely on arguments against materialism in confronting this dilemma, and difficulties with arguments in favor of phenomenism, we find ourselves pushed to reject the mental paint conception rather than materialism. Or at any rate, it is hard to see how the proponent of the zombie argument can carry the burden of proof that lies with her. Thus, whether or not those premises of the zombie argument are true, the argument fails to refute materialism. (shrink)

David Chalmers' conceivability argument against physicalism relies on the entailment from a priori conceivability to metaphysical possibility. The a posteriori physicalist rejects this premise, but is consequently committed to psychophysical strong necessities. These don't fit into the Kripkean model of the necessary a posteriori, and they are therefore, according to Chalmers, problematic. But given semantic assumptions that are essential to the conceivability argument, there is reason to believe in microphysical strong necessities. This means that some of Chalmers' criticism is unwarranted, (...) and the rest equally afflicts the dualist. Moreover, given that these assumptions are independently plausible, there's a general case to be made for the existence of strong necessities outside the psychophysical domain. (shrink)

If zombies were conceivable in the sense relevant to the ‘conceivability argument’ against physicalism, a certain epiphenomenalistic conception of consciousness—the ‘e-qualia story’—would also be conceivable. But (it is argued) the e-qualia story is not conceivable because it involves a contradiction. The non-physical ‘e-qualia’ supposedly involved could not perform cognitive processing, which would therefore have to be performed by physical processes; and these could not put anyone into ‘epistemic contact’ with e-qualia, contrary to the e-qualia story. Interactionism does not enable zombists (...) to escape these conclusions. (shrink)

Zombies and minimal physicalism -- The case for zombies -- Zapping the zombie idea -- What has to be done -- Deciders -- Decision, control, and integration -- De-sophisticating the framework -- Direct activity -- Gap? What gap? -- Survival of the fittest.

Philosophical zombies are exactly as physicalists suppose we are, right down to the tiniest details, but they have no conscious experiences. (It is presupposed that all explicable physical events are explicable physically.) Are such things even logically possible? My aim is to contribute to showing not only that the answer is 'No', but why. (I concede that systems superficially like human beings might exist and lack consciousness.) My strategy has two prongs: a fairly brisk argument which demolishes the zombie idea; (...) followed by an attempt to throw light on how something can qualify as a conscious perceiver. The argument to show that zombies are impossible exploits the point that in order to be able to detect our own 'qualia' we should have to be somehow sensitive to them; which the zombie idea rules out. The attempt to make clear why my zombie twin must be conscious exploits the idea that we have a reasonably clear grasp of a 'Basic Package' of psychological concepts. (shrink)

Philosophers have traditionally held that claims about necessities and possibilities are to be evaluated by consulting our philosophical intuitions; that is, those peculiarly compelling deliverances about possibilities that arise from a serious and reflective attempt to conceive of counterexamples to these claims. But many contemporary philosophers, particularly naturalists, argue that intuitions of this sort are unreliable, citing examples of once-intuitive, but now abandoned, philosophical theses, as well as recent psychological studies that seem to establish the general fallibility of intuition.In the (...) first two sections of this paper, I evaluate these arguments, and also the counter-arguments of contemporary defenders of tradition. In the next two sections, I sketch an alternative account of the role of philosophical intuitions that incorporates elements of traditionalism and naturalism - and defend it against other such views. In the final section, however, I discuss intuitions about conscious experience, and acknowledge that my view may not extend comfortably to this case. This may seem unfortunate, since so much contemporary discussion of the epistemology of modality seems motivated by worries about the mind-body problem, and informed by the position one wishes to endorse. But, as I argue, if conscious experience is indeed an exception to the view I suggest in this paper, it is an exception that proves - and can illuminate - the rule. (shrink)

A philosophical zombie is a being indistinguishable from an ordinary human in every observable respect, but lacking subjective consciousness. Zombiehood implies *linguistic indiscriminability*, the zombie tendency to talk and even do philosophy of mind in language indiscriminable from ordinary discourse. Zombies thus speak *Zombish*, indistinguishable from English but radically distinct in reference for mental terms. The fate of zombies ultimately depends on whether Zombish can be consistently interpreted. If it can be interpreted consistently, then zombies remain possible, but no test (...) could ever reveal whether anyone (oneself included) is speaking Zombish. Any materialist theory of consciousness is therefore already a theory in Zombish, and is equally confirmable in its human language edition (applicable to humans) and its zombie-language edition (applicable to zombies). On the other hand, if Zombish cannot be consistently interpreted, then the zombies described in Zombish are logically impossible. Either way, the search for a materialistic theory of consciousness should be untroubled by the (possible) zombies among us. (shrink)

Back in the late 1950s, a wonderful thing happened to metaphysics.

A prevailing view in contemporary philosophy of mind is that zombies are logically possible. I argue, via a thought experiment, that if this prevailing view is correct, then I could be transformed into a zombie. If I could be transformed into a zombie, then surprisingly, I am not certain that I am conscious. Regrettably, this is not just an idiosyncratic fact about my psychology; I think you are in the same position. This means that we must revise or replace some (...) important positions in the philosophy of mind. We could embrace radical skepticism about our own consciousness, or maintain the complete and total infallibility of our beliefs about our own phenomenal experiences. I argue that we should actually reject the logical possibility of zombies. (shrink)

I develop advice to the reductionist about consciousness in the form of a transcendental argument that depends crucially on the sorts of knowledge claims concerning consciousness that, as crucial elements in the anti-reductionists’ epistemicgap arguments, the anti-reductionist will readily concede. The argument that I develop goes as follows. P1. If I know that I am not a zombie, then phenomenal character is (a certain kind of) conceptualized egocentric content. P2. I know that I am not a zombie. P3. Phenomenal character (...) is (a certain kind of) conceptualized egocentric content. P4. Fixing my physical properties fixes my conceptualized egocentric contents. C. Fixing my physical properties fixes my phenomenal properties. (shrink)

I argue that zombies are inconceivable. More precisely, I argue that the conceivability-intuition that is used to demonstrate their possibility has been misconstrued. Thought experiments alleged to feature zombies founder on the fact that, on the one hand, they _must_ involve first-person imagining, and yet, on the other hand, _cannot_. Philosophers who take themselves to have imagined zombies have unwittingly conflated imagining a creature who lacks consciousness with imagining a creature without also imagining the consciousness it may or may not (...) possess. (shrink)

From the AI point of view, consciousness must be regarded as a collection of interacting processes rather than the unitary object of much philosophical speculation. We ask what kinds of propositions and other entities need to be designed for consciousness to be useful to an animal or a machine. We thereby assert that human consciousness is useful to human functioning and not just and epiphenomenon. Zombies in the sense of Todd Moody's article are merely the victims of Moody's prejudices. To (...) behave like humans, zombies will need what Moody might call pseudo-consciousness, but useful pseudo-consciousness will share all the observable qualities of human consciousness including what the zombie will be able to report. Robots will require a pseudo-consciousness with many of the intellectual qualities of human consciousness but will function successfully with few if any human emotional conscious qualities if that is how we choose to build them. (shrink)