This paper is mostly about the role of modal system S5 in conceivability arguments against, as well as in the defense of, different versions of physicalism. Jonathon VandenHombergh argued in a recent article that “[s]o far as the modal epistemology of reduction is concerned, therefore, it pays to go intrinsic.” His reasoning is that while the weaker, extrinsic version of reductive physicalism is vulnerable to conceivability arguments, the stronger, intrinsic, version is uniquely resistant to this type of challenge. (...) To get to this surprising conclusion, VandenHombergh claims that the standard strategies of preempting the Dualist’s reasoning rely on some premise(s) that the Dualist can do without: one such premise is axiom-scheme S5. I will argue that the use of S5 is legitimate in countering the Dualist, as she herself relies on it, not to secure the _validity_ of her arguments as VandenHombergh assumes, but rather, its _soundness_. I will also argue that this axiom-scheme is tacitly present in the auxiliary premises the stronger, intrinsic version of physicalism relies on: Kripke’s postulates about identity and non-identity statements. Indeed, this paper will forge an interesting and potentially important connection between Kripke’s postulates and modal system S5. (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.

The Humean view that conceivability entails possibility can be criticized via input from cognitive psychology. A mainstream view here has it that there are two candidate codings for mental representations (one of them being, according to some, reducible to the other): the linguistic and the pictorial, the difference between the two consisting in the degree of arbitrariness of the representation relation. If the conceivability of P at issue for Humeans involves the having of a linguistic mental representation, then (...) it is easy to show that we can conceive the impossible, for impossibilities can be represented by meaningful bits of language. If the conceivability of P amounts to the pictorial imaginability of a situation verifying P, then the question is whether the imagination at issue works purely qualitatively, that is, only by phenomenological resemblance with the imagined scenario. If so, the range of situations imaginable in this way is too limited to have a significant role in modal epistemology. If not, imagination will involve some arbitrary labeling component, which turns out to be sufficient for imagining the impossible. And if the relevant imagination is neither linguistic nor pictorial, Humeans will appear to resort to some representational magic, until they come up with a theory of a ‘third code’ for mental representations. (shrink)

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 , from there to a modal claim , and from there to a metaphysical claim.

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 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)

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.

I present an approach to our conceiving absolute impossibilities—things which obtain at no possible world—in terms of ceteris paribus intentional operators: variably restricted quantifiers on possible and impossible worlds based on world similarity. The explicit content of a representation plays a role similar in some respects to the one of a ceteris paribus conditional antecedent. I discuss how such operators invalidate logical closure for conceivability, and how similarity works when impossible worlds are around. Unlike what happens with ceteris paribus (...) counterfactual conditionals, the closest worlds are relevantly closest belief-worlds: closest to how things are believed to be, rather than to how they are. Also, closeness takes into account apriority and the opacity of intentional contexts. (shrink)

The conceivability argument against physicalism1 starts from the prem- ises that: It is conceivable that I have a zombie-twin, i.e., that there is someone who is physically identical to me and yet who lacks phenomenal con- sciousness; and If it is conceivable that I have a zombie-twin, then it is possible that I have a zombie-twin. These premises entail that physicalism is false, for physicalism is the claim—or can be assumed for our purposes to be the claim2—that.

Materialism in the philosophy of mind is the thesis that the ultimate nature of the mind is physical; there is no sharp discontinuity in nature between the mental and the non-mental. Anti-materialists asser t that, on the contrary, mental phenomena are different in kind from physical phenomena. Among the weapons in the arsenal of anti-materialists, one of the most potent has been the conceivability argument. When I conceive of the mental, it seems utterly unlike the physical. Anti-materialists insist that (...) from this intuitive difference we can infer a genuine meta-physical difference. Materialists retor t that the nature of reality, including the ultimate natures of its constituents, is a matter for discovery; an objective fact that cannot be discerned a priori. In this paper I under take to provide an explicit analysis of the dialectic that surrounds the conceivability argument. My principal conclusion is that the materialist is right in resisting the reasoning that star ts from considerations of what is conceivable and ends with genuine metaphysical conclusions. However my approach is much more sympathetic to the anti-materialist position than is the standard materialist line, and I will provide a limited defense of some crucial aspects of the anti-materialist position. Materialism will emerge from this fight intact, but shaken. (shrink)

The starting point of this paper is an argument to the conclusion that the definition of metaphysical possibility in terms of correct conceivability, conceivability informed by knowledge of relevant essences, found in Rosen (2006) is equivalent to a version of the essentialist definition of metaphysical necessity. This argument appears to show that correct conceivability is a notion of conceivability by name only and is therefore of no interest to epistemologists of modality. In this paper, I present (...) the equivalence argument, explain the idealizing assumptions involved in it and sketch a version of the conceivability approach which weakens these assumptions in order to show that the notion of correct conceivability can still play a specific limited role in the epistemology of modality. (shrink)

According to haecceitism, some maximal possibilities differ even while they are qualitatively indiscernible. Since haecceitism is a modal thesis, it is typically defended by appeal to conceivability arguments. These arguments require us to conceive of qualitatively indiscernible possibilities that differ only with respect to the identity of the individuals involved. This paper examines a series of conceivability arguments for haecceitism and a variety of anti-haecceitist responses. It concludes that there is no irresistible conceivability argument for haecceitism even (...) while anti-haecceitist responses do come with certain notable commitments. (shrink)

According to the ‘conceivability argument’ [1] it’s conceivable that a conscious human being H may have a perfect physical duplicate H* who isn’t conscious, [2] whatever is conceivable is possible, therefore [3] H* may possibly exist. This paper argues that the conceivability argument can’t help in discussion of the ‘mind–body problem’ even if [2] is allowed to be true. This is not because [1] is false, but because we don’t and can’t know enough about the nature of the (...) physical to know whether or not [1] is true. This follows from ‘the silence of physics’—the fact that physics neither does nor can tell us about the intrinsic non-structural nature of the physical, and the consequences of this fact for any adequate account of the meaning of the word ‘physical’. (shrink)

Some people might be tempted by modal ontological arguments from the possibility that God exists to the conclusion that God in fact exists. They might also be tempted to support the claim that possibly God exists by appealing to the conceivability of God’s existence. In this chapter, I introduce three constraints on an adequate theory of philosophical conceivability. I then consider and develop both imagination-based accounts of conceivability and conceptual coherence-based accounts of conceivability. Finally, I return (...) to the modal ontological argument and consider whether the premise that possibly God exists can be supported by some conceiving. (shrink)

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.".

Christopher Hill contends that the metaphysical modalities can be reductively explained in terms of the subjunctive conditional and that this reductive explanation yields two tests for determining the metaphysical modality of a proposition. He goes on to argue that his reductive account of the metaphysical modalities in conjunction with his account of modal knowledge underwrites the further conclusion that conceivability does not provide a reliable test for metaphysical possibility. I argue (1) that Hill’s reductive explanation of the metaphysical modalities (...) in terms of the subjunctive conditional does not yield a reductive explanation of knowledge of metaphysical modality in terms of knowledge of subjunctive conditionals, and (2) that his account of modal knowledge is at odds with his contention that conceivability does not provide epistemic access to metaphysical possibility. (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. One purpose of this paper is to argue that the notion is not fruitfully explicated in terms of the imagination. The most natural way of presenting a notion of conceivability qua imaginability is open to cogent criticism. In order to avoid such criticism, an advocate of the modal insightfulness (...) of the imagination must broaden the idea of what it is to be imaginable. I argue that this required broadening renders the imagination idle . Consequently, I distinguish two different accounts of the evidential basis of modal knowledge and present a more general argument that concludes that the very notion of conceivability should be eschewed in modal epistemology. (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)

In this paper I argue that certain so-called conceivability arguments fail to show that a currently popular version of physicalism in the philosophy of mind is false. Concentrating on an argument due to David Chalmers, I first argue that Chalmers misrepresents the relation between conceivability and possibility. I then argue that the intuition behind the conceivability of so-called zombie worlds can be accounted for without having to suppose that such worlds are genuinely conceivable. I conclude with some (...) general remarks about the nature of conceivability. (shrink)

Conceivability arguments constitute a serious threat against reductive physicalism. Recently, a number of authors have proven and characterized a devastating logical truth centered on these arguments: namely, that their soundness entails the inconceivability of reductive physicalism. In this paper, I demonstrate that this is only a logical truth when reductive physicalism is interpreted in its stronger, intrinsic sense, as opposed to its weaker—yet considerably more popular—extrinsic sense. The basic idea generalizes: perhaps surprisingly, stronger forms of reduction are uniquely resistant (...) to the conceivability arguments opposing them. So far as the modal epistemology of reduction is concerned, therefore, it pays to go intrinsic. (shrink)

In contemporary philosophy of mind, the conceivability argument against physicalism is often used to support a form of dualism, which takes consciousness to be ontologically fundamental and distinct from physical matter. Recently, some proponents of the conceivability argument have also shown interest in panpsychism, which is the view that mentality is ubiquitous in the natural world. This paper examines the extent to which panpsychism can be sustained if the conceivability argument is taken seriously. I argue that panpsychism’s (...) ubiquity claim permits a strong reading or a weak reading. This presents a dilemma. On the one hand, the strong reading, which is typically characterised as a form of monism, is undermined by the conceivability argument. On the other hand, the weak reading, while compatible with the conceivability argument, turns out just to be a special case of dualism. I also show that the related position of panprotopsychism cannot provide a tenable monist position because it too cannot withstand the challenge of the conceivability argument. Therefore, if the conceivability argument is taken seriously, then we are committed to a dualist metaphysics, regardless of whether or not we accept the ubiquity claim. (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)

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 a recent paper, Dennis Plaisted examines an important argument that Leibniz gives for the existence of primitive concepts. After sketching a natural reading of this argument, Plaisted observes that the argument appears to imply something clearly inconsistent with Leibniz’s other views. To save Leibniz from contradiction, Plaisted offers a revision. However, his account faces a number of serious difficulties and therefore does not successfully eliminate the inconsistency. We explain these difficulties and defend a more plausible alternative. In the process, (...) we call attention to the neglected topic of Leibniz’s views on the nature of conceiving, and reveal his commitment to the somewhat surprising thesis that one can conceive something through a concept even if one has no conscious grasp of that concept. (shrink)

Las intuiciones basadas en la perspectivade la primera persona fácilmente nospueden inducir a error sobre lo que es yno es concebible. Este punto usualmentese presenta como apoyo de posicionesreduccionistas comunes sobre el problemamente-cuerpo, pero considero que se puedeseparar de tal perspectiva. Me pareceque la fuerte apariencia de contingenciaen la relación entre el funcionamiento delorganismo físico y la mente consciente–una apariencia que depende directa oindirectamente de la perspectiva de laprimera persona– tiene que ser una ilusión.Enotraspalabras,creoquehayunaconexiónnecesariaenambasdireccionesentre lo físico y lo mental, pero (...) que nopuede descubrirse a priori. La opinión sedivide fuertemente entre la credibilidad dealgún tipo de reduccionismo funcionalista,y no examinaré mis razones para ubicarmeen el lado antireduccionista de este debate.Mi lectura del asunto es que nuestra faltade habilidad para obtener una concepcióninteligible de la relación mente-cuerpo esun signo de la inadecuación de nuestrosconceptos actuales, y que se requiere algúngrado de desarrollo.The Intuitions based on the first-personperspective can easily mislead us aboutwhat is and is not conceivable. This pointis usually made in support of familiarreductionist positions on the mind-bodyproblem, but I believe it can be detachedfrom that approach. It seems to me thatthe powerful appearance of contingency inthe relation between the functioning of thephysical organism and the conscious mind–an appearance that depends directly orindirectly on the first person– perspectivemust be an illusion. In other words, I believethatthereisanecessaryconnectioninbothdirectionsbetweenthephysicalandthemental,butthatitcannot bediscovereda priori. Opinion is strongly divided on thecredibility of some kind of functionalistreductionism, and I won’t go through myreasons for being on the antireductionistside of that debate.My reading of the situation is that ourinability to come up with an intelligibleconception of the relation between mindand body is a sign of the inadequacy of ourpresent concepts, and that some developmentis needed. (shrink)

The purpose of this article is to defend Hume's claim that whatever is conceivable is possible from a criticism by William Kneale. Kneale argues that although a mathematician can conceive of the falsehood of the Goldbach conjecture, he does not conclude that it is not necessarily true. The author suggests that by taking into account Hume's distinction between intuitive and demonstrative knowledge, a revised version of his claim can be offered which is not open to Kneale's criticism.

This article is a discussion of Hume's maxim Nothing we imagine is absolutely impossible. First I explain this maxim and distinguish it from the principle Whatever cannot be imagined (conceived), is impossible. Next I argue that Thomas Reid's criticism of the maxim fails and that the arguments by Tamar Szábo Gendler and John Hawthorne for the claim that “it is uncontroversial that there are cases where we are misled” by the maxim are unconvincing. Finally I state the limited but real (...) value of the maxim: it does help us, in certain cases, reliably to make up our minds. Along the way I show that Reid, his criticism of the maxim notwithstanding, actually employs it, and I furthermore argue that the principle What is inconceivable, is impossible is spurious. (shrink)

In this paper, we argue that ‘Weak Modal Rationalism’, which is the view that ideal primary positive conceivability entails primary metaphysical possibility, is self-defeating. To this end, we outline two reductio arguments against ‘Weak Modal Rationalism’. The first reductio shows that, from supposing that ‘Weak Modal Rationalism’ is true, it follows that conceivability both is and is not conclusive evidence for possibility. The second reductio shows that, from supposing that ‘Weak Modal Rationalism’ is true, it follows that it (...) is possible that ‘Weak Modal Rationalism’ is necessarily false, and hence that ‘Weak Modal Rationalism’ is false. We then argue that adopting a weaker position according to which conceivability is merely prima facie evidence for possibility provides limited protection from our criticism of conceivability arguments. (shrink)

This paper examines the ramifications of Hume's view of the relation of conceivability to metaphysical possibility. It argues that the limitations Hume places of the representations involved in moves to conceivability to metaphysical possibility preclude any straightforward argument against full-blooded causal realism in Hume from conceivability. Furthermore, our finding certain states of affairs conceivable when they are not metaphysically possible is perfectly compatible with the thrust of the causal realist position.

This paper challenges the soundness of the two-dimensional conceivability argument against the derivation of phenomenal truths from physical truths in light of a hyperintensional, ground-theoretic regimentation of the ontology of consciousness. The regimentation demonstrates how ontological dependencies between truths about consciousness and about physics cannot be witnessed by epistemic constraints, when the latter are recorded by the conceivability—i.e., the epistemic possibility—thereof. Generalizations and other aspects of the philosophical significance of the hyperintensional regimentation are further examined.

Intuitions based on the first-person perspective can easily mislead us about what is and is not conceivable.1 This point is usually made in support of familiar reductionist positions on the mind-body problem, but I believe it can be detached from that approach. It seems to me that the powerful appearance of contingency in the relation between the functioning of the physical organism and the conscious mind -- an appearance that depends directly or indirectly on the first- person perspective -- must (...) be an illusion. But the denial of this contingency should not take the form of a reductionist account of consciousness of the usual type, whereby the logical gap between the mental and the physical is closed by conceptual analysis -- in effect, by analyzing the mental in terms of the physical. (shrink)

Chalmers argues that zombies are possible and that therefore consciousness does not supervene on physical facts, which shows the falsity of materialism. The crucial step in this argument – that zombies are possible – follows from their conceivability and hence depends on assuming that conceivability implies possibility. But while Chalmers’s defense of this assumption – call it the conceivability principle – is the key part of his argument, it has not been well understood. As I see it, (...) Chalmers’s defense of the conceivability principle comes in his response to the so-called objection from a posteriori necessity. The defense aims at showing that there is no gap between conceivability and possibility since no such gap can be generated by necessary a posteriori truths. I will argue that while Chalmers is right to the extent that there is no gap between conceivability and possibility within the standard Kripkean model of a posteriori necessity, his general conclusion is not justified. This is because the conceivability principle might be inconsistent with a posteriori necessity understood in some non-Kripkean way and Chalmers has not shown that no such alternative understanding of a posteriori necessity is available. (shrink)

The dissertation addresses the mind-body problem, and in particular, the problem of how to fit phenomenal consciousness into the rest of reality. Phenomenal consciousness - the what it’s like feature of experience - can appear to the scientifically inclined philosopher to be deeply mysterious. It is difficult to understand how the swirl of atoms in the void, the oscillation of field values, the firing of synapses, or anything physical can add up to the smells, tastes, feelings, moods, and so forth (...) that comprise our phenomenal experience. There is a series of arguments - the so-called “Conceivability Arguments” - that spells out this puzzlement. If this arguments are successful then there is no place for phenomenal consciousness in a completely physical reality. The main conclusion of this dissertation is that the Conceivability Arguments are all dependent on a flawed premiss, and that therefore these arguments - perhaps the most powerful among anti-physicalist arguments - all fail. Conceivability Arguments begin with the premiss that we can conceive of any physical or functional facts obtaining without there being any phenomenal experience at all. This is sometimes expressed by saying that zombies (i.e., beings that are our physical and functional duplicates, but possess no phenomenal experiences) are conceivable. The claim that zombies are conceivable does not have to do with our powers of imagination, or our psychological abilities, but rather with the nature of physical and phenomenal concepts. The reason that zombies are claimed to be conceivable is that each person’s thinking about phenomenal properties is completely dependent on her first person acquaintance with her own experience. From this assertion of conceivability it is inferred that zombies are genuinely possible. And this conclusion is incompatible with physicalism as that doctrine is usually understood. I argue that these arguments all fail; they are refuted by a master argument that I call “the Zombie Refutation.” The reason they fail has to do with the very nature of phenomenal concepts that gives rise to the conceivability of zombies. Because of the special nature of these concepts, the principle underlying the Conceivability Arguments - that principle that links conceivability and possibility - turns out to be self-refuting. Thus, the zombies that the Conceivability Arguments supposedly demonstrate to be possible, return to undermine those very arguments; a fitting revenge. (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)

Wright (In Gendler and Hawthorne (Eds.), Conceivability and possibility, 2002) rejects some dominant responses to Kripke’s modal argument against the mind-body identity theory, and instead he proposes a new response that draws on a certain understanding of counterpossibles. This paper offers some defensive remarks on behalf of Lewis’ objection to that argument, and it argues that Wright’s proposal fails to fully accommodate the conceivability intuitions, and that it is dialectically ineffective.

Conceiving a child by way of embryo selection and tissue matching to benefit a sick sibling is generally justified on the grounds that as well as the potential to save the sick child, there is a benefit for the new baby. The new baby is selected so he or she will not have the disease suffered by the first child. It is not possible, however, to select against conditions for which there is no test and Jamie Whitaker’s birth is a (...) case where the process of in vitro fertilisation with tissue matching is viewed as being of benefit only to a third party—the sick child. Some people object to using the technology for this purpose. There are also good reasons to argue that the technology should be used to save a sick child, and that it would be morally remiss for Jamie’s parents not to consent to the use of his cord blood. (shrink)

Conceivability is an important source of our beliefs about what is possible; inconceivability is an important source of our beliefs about what is impossible. What are the connections between the reliability of these sources? If one is reliable, does it follow that the other is also reliable? The central contention of this paper is that suitably qualified the reliability of inconceivability implies the reliability of conceivability, but the reliability of conceivability fails to imply the reliability of inconceivability.

In the history of modern philosophy systematic connections were assumed to hold between the modal concepts of logical possibility and necessity and the concept of conceivability. However, in the eyes of many contemporary philosophers, insuperable objections face any attempt to analyze the modal concepts in terms of conceivability. It is important to keep in mind that a philosophical explanation of modality does not have to take the form of a reductive analysis. In this paper I attempt to provide (...) a response-dependent account of the modal concepts in terms of conceivability along the lines of a nonreductive model of explanation. (shrink)

In its formlessness and potentiality, prime matter is a problematic entity of medieval metaphysics and its ontological limitations drastically affect human possibility of conceiving it. In this article, I analyse three influential strategies elaborated to justify an epistemic access to prime matter. They are incidental perception, negative abstraction, and analogy. Through a systematic and historical analysis of these procedures, the article shows the richness of interpretations and theoretical stakes implied by the conundrum of how prime matter can be known by (...) human beings. In particular, the reasons behind the later medieval acceptance of analogy as the main way to unveil prime matter become clearer by pointing out the correlation between the ontological and epistemological levels of the medieval examination of prime matter. (shrink)

Materialism is the view according to which a zombie world is metaphysically impossible. Assuming that zombies are conceivable in the sense that we cannot rule out a priori that our world is a zombie world, materialists must hold that a zombie world is metaphysically impossible despite being conceivable. There are no good reasons to think that this view (type-B materialism) is false, since there are no good reasons to think that the corresponding phenomenal and physical/functional concepts cannot be distinct concepts (...) of the same thing. Nonetheless, we cannot understand how type-B materialism can be true. We cannot understand this, because we cannot in principle explain how a zombie world could be impossible despite being conceivable. (shrink)

Each year, tens of thousands of children are conceived with donated gametes (sperm or eggs). By some estimates, there are over one million donor-conceived people in the United States and, of course, many more the world over. Some know they are donor-conceived. Some do not. Some know the identity of their donors. Others never will. -/- Questions about what donor-conceived people should know about their genetic progenitors are hugely significant for literally millions of people, including donor-conceived people, their parents, and (...) donors. But the practice of gamete donation also provides a vivid occasion for thinking about questions that matter to everyone. What is the value of knowing who your genetic progenitors are? How are our identities bound up with knowing where we come from? What obligations do parents have to their children? And what makes someone a parent in the first place? -/- In Conceiving People: Identity, Genetics and Gamete Donation, Daniel Groll argues that people who plan to create a child with donated gametes should choose a donor whose identity will be made available to the resulting child. This is not, Groll argues, because having genetic knowledge is fundamentally important. Rather, it is because donor-conceived people are likely to develop a significant interest in having genetic knowledge and parents must help satisfy their children's significant interests. In other words, because a donor-conceived person is likely to care about having genetic knowledge, their parents should care too. (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. Thirteen leading philosophers present specially-written essays, and a substantial introduction is provided by the volume editors, who demonstrate the importance of these topics to a wide range of issues in contemporary philosophy.

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.