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)

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)

The classical view of the relationship between necessity and apriority, defended by Leibniz and Kant, is that all necessary truths are known a priori. The classical view is now almost universally rejected, ever since Saul Kripke and Hilary Putnam discovered that there are necessary truths that are known only a posteriori. However, in recent years a new debate has emerged over the epistemology of these necessary a posteriori truths. According to one view – call it the neo-classical view – knowledge (...) of a necessary truth always depends on at least one item of a priori knowledge. According to the rival view – call it the neoempiricist view – our knowledge of necessity is sometimes broadly empirical. In this paper I present and defend an argument against the neo-empiricist view. I argue that knowledge of the necessity of a necessary truth could not be broadly empirical. (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.

forthcoming in Philosophical Perspectives.

Kripke claims that there are necessary a posteriori truths and contingent a priori truths. These claims challenge the traditional Kantian view that (K)  All knowledge of necessary truths is a priori and all a priori knowledge is of necessary truths. Kripke’s claims continue to be resisted, which indicates that the Kantian view remains attractive. My goal is to identify the most plausible principles linking the epistemic and the modal. My strategy for identifying the principles is to investigate two related questions. (...) Are there compelling general supporting arguments for (K)? Are there decisive counterexamples to (K)? My investigation uncovers two intuitively plausible principles that are not open to decisive counterexamples but which enjoy no compelling independent support. (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).

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)

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)

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.".

Visualizings, the simplest imaginings which employ visual imagery, have certain characteristic features; they are perspectival, for instance. Also, it seems that some but not all of our visualizings are imaginings of seeings. But it has been forcefully argued, for example by M.G.F. Martin and Christopher Peacocke, that all visualizings are imaginings of visual sensations. I block these arguments by providing an account of visualizings which allows for their perspectival nature and other features they typically have, but which also explains how (...) we can visualize things without thereby imagining visual sensations. (shrink)

Abstract: In recent years two-dimensional semantics has become one of the most serious alternatives to Millianism for the proper interpretation of modal discourse. It has origins in the works of a diverse group of philosophers, and it has proven popular as an interpretation of both language and thought. It has probably received most of its attention, however, because of its use by David Chalmers in his arguments against materialism. It is this more metaphysical application of two-dimensionalism that is the concern (...) in this paper. For though there is probably something salvageable from two-dimensionalism as a way to explain the content of thought, as a metaphysical tool it should be abandoned. In this paper I aim to establish this point by reductio: if 'metaphysical' two-dimensionalism is assumed, it can be shown to be false. (shrink)

How do we know what's (metaphysically) possible and impossible? Kripke-Putnam considerations suggest that possibility is not merely a matter of (coherent) conceivability/imaginability. For example, we can coherently imagine that Hesperus and Phosphorus are distinct objects even though they are not possibly distinct. Despite this apparent problem, we suggest, nevertheless, that imagination plays an important role in an adequate modal epistemology. When we discover what is possible or what is impossible, we generally exploit important connections between what is possible and what (...) we can coherently imagine. (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.

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 (however elaborately this is done -- and I count functionalism as such a theory, along with the topic-neutral causal role analyses of mental concepts from which it descends). (shrink)

Abstract:  Thought experiments about the self seem to lead to deeply conflicting intuitions about the self. Cases imagined from the 3rd person perspective seem to provoke different responses than cases imagined from the 1st person perspective. This paper argues that recent cognitive theories of the imagination, coupled with standard views about indexical concepts, help explain our reactions in the 1st person cases. The explanation helps identify intuitions that should not be trusted as a guide to the metaphysics of the self.

The big philosophical questions about modality are metaphysical and epistemic: What are the truth-makers for our modal judgments? What justifies our modal judgments? These two questions are notoriously problematic.¹ What fact could make it true that blue swans are possible? And, assuming there is such a fact, what justifies our belief in that fact? Few philosophers think that there are easy answers here (see e.g. Gendler and Hawthorne 2002). Indeed, one might regard modal realism—the view that there exist infinitely many (...) possible worlds (Lewis 1986)—as revealing the depth of philosophical desperation over modality. (shrink)

Ignorance and Imagination advances a novel way to resolve the central philosophical problem about the mind: how it is that consciousness or experience fits into a larger naturalistic picture of the world. The correct response to the problem, Stoljar argues, is not to posit a realm of experience distinct from the physical, nor to deny the reality of phenomenal experience, nor even to rethink our understanding of consciousness and the language we use to talk about it. Instead, we should view (...) the problem itself as a consequence of our ignorance of the relevant physical facts. Stoljar shows that this change of orientation is well motivated historically, empirically, and philosophically, and that it has none of the side effects it is sometimes thought to have. The result is a philosophical perspective on the mind that has a number of far-reaching consequences: for consciousness studies, for our place in nature, and for the way we think about the relationship between philosophy and science. (shrink)

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)

Kripke, argued like this: it seems possible that E; the appearance can't be explained away as really pertaining to a "presentation" of E; so, pending a different explanation, it is possible that E. Textbook Kripkeans see in the contrast between E and its presentation intimations of a quite general distinction between two sorts of meaning. E's secondary or a posteriori meaning is the set of all worlds w which E, as employed here, truly describes. Its primary or a priori meaning (...) is the set of all w such that if w is actual, then E is true. "Conceivability error" occurs when a primary possibility is mistaken for a secondary one. Textbook Kripkeanism is rejected on the grounds that it makes meaning too modal and modality too much a matter of meaning. (shrink)

In recent work Timothy Williamson argues that the epistemology of metaphysical modality is a special case of the epistemology of counterfactuals. I argue that Williamson has not provided an adequate argument for this controversial claim, and that it is not obvious how what he says should be supplemented in order to derive such an argument. But I suggest that an important moral of his discussion survives this point. The moral is that experience could play an epistemic role which is more (...) epistemically significant than a mere 'enabling' role but not equivalent to an evidential role. (shrink)

The epistemology of modality is gradually coming to play a central role in general discussions about modality. This paper is a contribution in this direction, in particular I draw a comparison between Lewis’s Modal realism and Timothy Williamson’s recent account of modality in terms of counterfactual thinking. In order to have criteria of evaluation, I also formulate four requirements which are supposed to be met by any theory of modality to be epistemologically adequate.