all papers by date of writing

Journal of Consciousness Studies 27:201-226.

Journal of Consciousness Studies 27:258-81.

Journal of Consciousness Studies 27:227-57.

Nous 54:488-97, 2020. [pdf]

Disputatio, 2020. [pdf]

Forthcoming in (C. Wüthrich, B. Le Bihan, & N. Huggett, eds) Philosophy Beyond Spacetime. Oxford University Press. [pdf]

Forthcoming in Inquiry. [pdf]

Forthcoming in the Vienna Circle Institute Yearbook and in a book of articles on David Lewis’s philosophy. [pdf]

Review of Narrow Content, by Juhani Yli-Vakkuri and John Hawthorne. Notre Dame Philosophical Reviews, December 2018. A review of a book arguing that narrow content is impossible. [html]

Journal of Consciousness Studies 25:6-61.

In (M. Colombo, E. Irvine, and M. Stapleton, eds.) Andy Clark and His Critics. Wiley-Blackwell, 2018. A recent piece discussing (i) what is the extended mind thesis, exactly, and (ii) are there cases of extended consciousness, and if not, why not? [pdf] [philpapers]

A recent article using a structuralist view of the physical world to argue against global skepticism. Among other things this gives a sort of foundation for the argument in the Matrix paper below. [pdf] [philpapers]

In (W. Seager, ed.) The Routledge Handbook to Panpsychism (Routledge, 2018). A new paper exploring the prospects for idealism, the view that all reality is grounded in the mental. There is some discussion of traditional anti-realist idealism, but the focus is on a “realist” approach grounded in structuralism about the physical and the nonreductionism about the mental. I give the most attention to idealist views that grow out of panpsychism and cosmopsychism, namely micro-idealism and cosmic idealism. [pdf] [philpapers]

Forthcoming in Disputatio. On the metaphysics of virtual reality. I defend a sort of virtual realism and virtual digitalism (on which virtual objects are real digital objects) over virtual irrealism and virtual fictionalism (where virtual objects are fictional objects). With discussion of the definition of VR, of illusions in VR, of the value of VR and Nozick’s Experience Machine, of augmented reality and dreams, of the connection to structuralism and skepticism, and more. This paper will be the subject of a symposium on Disputatio with a number of commentaries and eventually a reply. [pdf] [philpapers]

Mind 125:499-510, 2016. A reply to David Braun’s response to Frege’s Puzzle and the Objects of Credence. Focuses on Braun’s guise-theoretic view of the objects of credence and why it leads to a nonreferentialist view in the philosophy of mind. [pdf] [philpapers]

Forthcoming in (Pautz and Stoljar, eds.) Themes from Ned Block. This paper focuses on the content of our experience of orientation, size, and shape, and argues that certain sorts of lifelong illusions involving these are impossible. This serves as support for a sort of spatial externalism and spatial functionalism. Thought experiments along the way include Mirror Earth, Doubled Earth, and Lorentz Earth. [pdf]

Analysis 74:676-697, 2014 (symposium on Constructing the World). [pdf] [philpapers]

Philosophy and Phenomenological Research 89: 249-69 (symposium on Constructing the World), 2014. [pdf] [philpapers]

Philosophy 1:3-31, 2015. Also in (T. Honderich, ed.) Philosophers of our Times, and in (J. Keller, ed.) Themes from Peter van Inwagen. The first part of this paper tries to isolate various ways in which philosophy makes progress and ways in which it makes less progress than the hard sciences. The central notion involves convergence to the truth on the big questions. The rest of the paper asks why philosophy makes less progress in this way. A number of answers are canvassed, but I think the question is still open. [pdf] [philpapers]

Philosophical Studies 171:535-44, 2014. A minor piece commenting on Herman Cappelen’s book Philosophy Without Intuitions. I argue for a sense in which philosophy relies on intuitions and try to get a bit clearer on the dialectical role that they play. [pdf] [philpapers]

Co-authored with Brian Rabern. Analysis 74:210-224, 2014. A number of philosophers (e.g. Scott Soames, Graham Forbes, Josh Dever) have argued that the problem of “nesting” epistemic contexts inside metaphysical modal contexts gives rise to problems for two-dimensionalism. Brian Rabern and I isolate the underlying problem and argue that it is a problem for almost everyone, not just for two-dimensionalism, and we spell out a possible two-dimensionalist solution. [pdf] [philpapers].

Co-authored with David Bourget. Philosophical Studies 171:535-44, 2014. In December 2009, David Bourget and I did a survey of professional philosophers, asking for their views on thirty philosophical questions. There were many interesting results. We write them up here. There will probably be a second survey in December 2019. [pdf] [philpapers]

Amherst Lecture in Philosophy, 2013. Reprinted in (T. Alter and Y. Nagasawa, eds.) Consciousness in the Physical World: Perspectives on Russellian Monism (OUP, 2015). Reprinted in (G. Bruntrup and L. Jaskolla, eds.) Panpsychism (OUP. 2017). This paper develops an argument for panpsychism as a sort of Hegelian synthesis of materialism and dualism. Along the way it distinguishes many varieties of panpsychism and develops a more general case for panprotopsychism and Russellian monism, while also addressing problems for these views. [pdf]

In (G. Bruntrup and L. Jaskolla, eds.) Panpsychism. Oxford University Press, 2017. This paper was written on the same weekend as the other paper on panpsychism, but it was published four years later due to the vagaries of publishing. Where the other paper develops a case for panpsychism and panprotopsychism, this paper develops the case against. It distinguishes a number of versions of the combination problem and tries to turn them into arguments. Panpsychism is still left standing at the end — but perhaps only just. [pdf] [philpapers]

Philosophical Studies 167:785-800. This paper is a reply to three commentaries by Philip Goff and David Papineau, Geoff Lee, and Joe Levine in a symposium on The Character of Consciousness. All three comments focused on the issue of strong necessities (another symposium on the book focuses on issues about the contents of consciousness), so this leads to a usefully unified and coherent exchange. [pdf] [philpapers]

My reply to comments in a symposium on The Character of Consciousness by Benj Hellie, Chris Peacocke, and Susanna Siegel. The three parts focus especially on acquaintance and attention, on spatial experience, and on Edenic perception. [pdf] [philpapers]

Journal of Cognitive Science. A reply to comments by Curtis Brown, Frances Egan, Stevan Harnad, Colin Klein, Gerard O’Brien, Marcin Milkowski, Brendan Ritchie, Michael Rescorla, Matthias Scheutz, Oron Shagrir, Mark Sprevak, Brandon Towl. With discussion of pluralism about computation, computation and representation, and of counterexamples of structuralist accounts of implementation. [pdf] [philpapers]

Journal of Consciousness Studies 19:141-67, 2012. This was my reply to 26 commentaries by Sue Blackmore, Nick Bostrom, Barry Dainton, Dan Dennett, Robin Hanson, Marcus Hutter, Ray Kurzweil, Drew McDermott, Jesse Prinz, Susan Schneider, Jurgen Schmidhuber, and others. This is my reply in turn. The whole symposium was published as a special issue of the journal and later as the oddly-subtitled book The Singularity: Could artificial intelligence really out-think us (and would we want it to) from Imprint Academic. For what it’s worth I think the argument for an intelligence explosion holds up pretty well. [pdf] [philpapers]

Analysis 71:411-19, 2011. This paper argues against the common view that all propositions of the form

are knowable a priori by arguing (via a simple logical proof!) that some are unknowable. Consequences for the correct understanding of apriority are discussed. [pdf] [philpapers]

Journal of Consciousness Studies 17:7-65, 2010. A long article on artificial superintelligence. I try to make the argument for a rapid “intelligence explosion” philosophically rigorous. There’s also some discussion of AI safety issues and mind uploading. There were subsequently 26 commentaries and my reply below. [pdf] [philpapers]

Philosophical Review 120:515-66, 2011. An analysis of what it is to have a verbal dispute and of how to dissolve them. With applications to philosophical method and to a number of philosophical disputes. I also use the framework to draw out consequences about primitive concepts and analyticity. [pdf] [philpapers]

Journal of Philosophy 108:387-415, 2011. This paper is more or less my defense of the a priori against Quine’s arguments from revisability and holding-true toward the end of “Two Dogmas”. I started off doing things in the 2D framework and then figured out that the arguments could be put more generally in a Bayesian framework, with standard Bayesian norms such as conditionalization making life pretty hard for the Quinean. There have already been quite a few responses to this one: e.g. by Gary Ebbs, Gurpreet Rattan, Damien Rochford, Robert Rupert, and Brett Topey. [pdf] [philpapers]

In (P. Grim, ed) Mind and Consciousness: 5 Questions. Automatic Press, 2008.

Foreword to Andy Clark's Supersizing the Mind

In Andy Clark, Supersizing the Mind\ . Oxford University Press, 2008. A foreword to Andy’s book where I discuss the iPhone as mind-extended and discuss what I think is the strongest objection to the thesis. I go to town on the iPhone idea in this TED talk on the extended mind. [pdf] [philpapers]

In (D. Chalmers, D. Manley, and R. Wasserman, eds.) Metametaphysics: New Essays on the Foundations of Ontology. This paper is a defense of a broadly Carnapian deflationism about ontological questions. I make sense of a version of Carnap’s internal/external distinction as the distinction between ordinary and ontological existence assertions. I distinguish between lightweight and heavyweight ontological realism and ontological anti-realism, and argue for the latter. I develop a way of making sense of Carnapian frameworks via “furnishing functions” that associate a domain of objects with a world. [pdf] [philpapers]

Nous 45:595-639, 2011. Develops the epistemic 2D paper into a Fregean account of propositions (as “enriched propositions” involving structures of primary intensions and referents) and gives an associated account of propositional attitude ascriptions. I use this framework to address many puzzles involving attitude ascriptions as well as various objections to the 2D framework. [pdf] [philpapers]

Analysis 67:170-72, 2007. A micro-paper arguing that certain common formulations of the Ramsey test and Moore’s-paradox reasoning leading to accepting omniscience claims such as ‘If p, then I believe that p’. This was mostly published for cuteness (OK, mainly for the title) rather than impact, since it’s obvious that there are better formulations of the Ramsey test that avoid the result. Replies by David Barnett (“Ramsey + Moore ≠ God”), Hannes Leitgeb (“God – Moore = Ramsey”) and John Williams point out that there are better formulations of the Ramsey test that avoid the result and say other interesting things besides. [pdf] [philpapers]

Mind 120:587-635, 2011. Uses Frege-style cases to argue that the objects of credence (that is, the objects to which credences are assigned) can’t be Russellian propositions or other reference-based entities, and argues for a 2D-ish Fregean account instead. Mind later published a reply by David Braun (see also this reply by Jesse Fitts) along with my reply in turn. pdf [philpapers]

For a session at the meeting of the American Philosophical Association, Central Division, in April 2006. This is a response to Scott Soames’ book Reference and Description: The Case Against Two-Dimensionalism. It focuses mainly on Soames’ broad critique and his own quasi-two-dimensional framework; other objections, especially concerning attitude ascriptions, are addressed in “Propositions and Attitude Ascriptions” and in “Two-Dimensional Semantics and the Nesting Problem”. Soames replied and I replied in turn. See also this earlier extended handout, Soames on Two-Dimensionalism, written for an exchange atArizona State University in January 2004.

In (B. McLaughlin, A. Beckermann, & S. Walter, eds) Oxford Handbook of the Philosophy of Mind (Oxford University Press, 2009), pp. 313-335. Expanded version in The Character of Consciousness (OUP, 2010). This long paper gives the fullest and best-developed version of my version of the conceivability argument against materialism using two-dimensional semantics. The focus is especially on the connection between conceivability and possibility and the issue of strong a posteriori necessities. Many objections are addressed! [pdf] [philpapers]

This paper discusses materialist attempts (by e.g. Hill, Loar, Papineau, Tye, and others) to appeal to phenomenal concepts to explain away the explanatory gap and other epistemic gaps. I argue that no such account can work: either the account does not explain the epistemic gap, or the relevant features of phenmenal concepts are themselves not explainable in physical terms. Forthcoming in Torin Alter and Sven Walter, Phenomenal Concepts and Phenomenal Knowledge: New Essays on Consciousness and Physicalism (OUP, 2006). [pdf] [philpapers]

In (E. Lepore and B. Smith, eds.) Oxford Handbook to the Philosophy of Language. A review piece on various approaches to two-dimensional semantics, and especially on the epistemic two-dimensionalism that I favor. This is a good place for an overview. [pdf] [philpapers]

In Perceptual Experience, edited by Tamar Gendler and John Hawthorne (Oxford University Press, 2006). This is a sequel to the previous paper. I argue that the phenomenology of perceptual experience grounds not just a sort of Fregean content, but also a more fundamental “Edenic” content, involving the representation of primitive properties that may not be instantiated in the world. Much of the paper concerns the relationship between these two sorts of content. [pdf] [philpapers]

In (M. Gazzaniga, ed) The Cognitive Neurosciences III. MIT Press, 2004. This paper discusses the agenda for a science of consciousness. I characterize the central task as the systematic integration of first-person data and third-person data, and lay out various concrete projects, discussing recent work in psychology and cognitive science along the way. I also discussed some obstacles, especially those tied to the methods for gathering first-person data. The paper appears in The Cognitive Neurosciences III, edited by Michael Gazzaniga (MIT Press, 2004). [pdf] [philpapers]

In The Future for Philosophy, edited by Brian Leiter (Oxford University Press, 2004). This paper concerns the relationship between the phenomenal character and representational content of perceptual experience, and the status of representationalism. I argue for a sort of nonreductive, narrow, Fregean representationalism, contrasting with the more common reductive, wide, Russellian representationalism. [pdf] [philpapers]

First published on thematrix.com in 2003, and printed in (C. Grau, ed) Philosophers Explore the Matrix (Oxford University Press, 2005). Reprinted in (T. Gendler, S. Siegel, & T. Cahn, eds) The Elements of Philosophy (McGraw-Hill, 2007). Reprinted in (S. Schneider, ed) Science Fiction and Philosophy (Wiley, 2009). I argue that even if we are in a Matrix-style simulation, most of our ordinary beliefs about the world are true. The hypothesis that we are in a Matrix is really a metaphysical hypothesis: one according to which physical objects are constituted by computations and all this was designed by a designer (in the next world up). I use this to argue against a sort of Cartesian global skepticism about the external world. [pdf] [philpapers]

In (P. Ludlow, Y. Nagasawa, & D. Stoljar, eds) There’s Something about Mary: Essays on Frank Jackson’s Knowledge Argument Against Physicalism. MIT Press, 2004. This paper applies the analysis of phenomenal concepts above to the knowledge argument against materialism. Most of this paper is drawn from with material in other papers, but there is a bit of new material in the second half on replies to the knowledge argument. It is forthcoming in There’s Something About Mary, an anthology of papers on the knowledge argument, edited by Peter Ludlow, Yujin Nagasawa, and Daniel Stoljar (MIT Press, 2004). [html] [philpapers]

Philosophy and Phenomenological Research 68:182-90. This is a commentary in a symposium on John Perry’s book Knowledge, Possibility, and Consciousness (MIT Press, 2001), which defends a materialist view against a number of arguments (the zombie argument, the knowledge argument, the modal argument), and addresses the discussion in my book. The online version includes an additional response to John Perry’s reply. [html] [philpapers]

In (P. Clayton and P. Davies, eds) The Re-Emergence of Emergence. Oxford University Press, 2006. On different notions of emergence: strong emergence (favored by philosophers), which involves something unpredictable in principle, which is therefore new and fundamental, and weak emergence (favored by scientists), which involves something surprising, which is therefore derivative but important. I give my own favored analyses and cases of these phenomena. [pdf] [philpapers]

Philosophical Issues 13:46-66, 2003. This one overlaps heavily with the early sections of “The Components of Content” but has a little different material. [html] [philpapers]

My remarks at the memorial service for David Lewis at Princeton University on February 8, 2002 .[html]

In (M. Garcia-Carpintero & J. Macia, eds) Two-Dimensional Semantics: Foundations and Applications (Oxford University Press, 2006). Abridged as “Epistemic Two-Dimensional Semantics” in Philosophical Studies 18:153-226, 2004. This monster paper (written for the Barcelona conference on two-dimensionalism, is a sort of “compare-and-contrast” on the various versions of two-dimensional semantics. It starts by motivating this sort of framework, and then discusses in detail the two main sorts of available understandings of the framework: contextual and epistemic understandings. I argue that contextual understandings (e.g. that of Stalnaker) can’t do the work that is required, but that an epistemic understanding can. I set out my own understanding in detail, and then locate existing versions of the framework in the conceptual space as set out. I now think that while this paper is useful for the initial motivation in the first few pages and for the compare-and-contrast, “The Nature of Epistemic Space” is much better at systematically setting out the foundations. An abridged version of this paper appeared as “Epistemic Two-Dimensional Semantics” in Philosophical Studies in 2004, with an interesting response by Laura Schroeter (who also has related critiques here and here). [html] [philpapers]

Analysis 62:155-57, 2002. A short paper with my preferred analysis (the correct analysis!) of the two-envelope paradox. It sets out a related scenario that combines elements of the St. Petersburg paradox and the two-envelope paradox, and uses this to diagnose where the decision-theoretic paradoxical reasoning goes wrong. [html] [philpapers]

In (S. Stich & F., Warfield, eds) Blackwell Guide to Philosophy of Mind. Blackwell, 2003. Also in (D. Chalmers, ed) Philosophy of Mind: Classical and Contemporary Readings (Oxford University Press, 2002). Reprinted (abridged) in( W. Lycan & J. Prinz, eds) Mind and Cognition: A Reader (Blackwell, 2007). This is an overview paper on the metaphysics of consciousness. It summarizes arguments against materialism, and uses these to give a detailed taxonomy of reductive and nonreductive views (three each). It covers some of the same ground as the first two papers below (although it’s oriented more toward metaphysics than toward science), while also covering some of the more technical material in my book and some new things. [pdf] [philpapers]

In (A. Egan and B. Weatherson, eds) Epistemic Modality. Oxford University Press, 2010. This foundational paper explores the framework of epistemically possible worlds, or scenarios. I examine various ways of understanding this epistemic space — one tied to centered possible worlds, and one tied directly to epistemic notions. I look at the relationship to metaphysical possibility, issues about trans-scenario identity, and infinitary issues tied to Kaplan’s paradox. And I outline some applications of the framework from this perspective, especially in grounding a broadly two-dimensional approach to meaning and content. This paper was online for 10 years or so before publication. The published version was revised significantly before publication, but I’ve kept online the original 2001 version , which among has some discussion of narrow content that didn’t make it into the published version. [pdf] [philpapers]

Co-authored with Tim Bayne. In (A. Cleeremans, ed) The Unity of Consciousness: Binding, Integration, Dissociation (Oxford University Press, 2003). We distinguish a number of different senses in which it might be said that a subject’s conscious experiences are unified, and isolate a central notion for which the claim that consciousness is necessarily unified is tenable without being trivial. We then discuss potential counterexamples to this unity thesis, and will consider the implications of the unity thesis for theories of consciousness more generally. This paper appears in The Unity of Consciousness: Binding, Integration, Dissociation (Oxford University Press, 2003) edited by Axel Cleeremans. [pdf] [philpapers]

In Philosophical Perspectives, vol. 16, 2002. Reprinted in (M. Davidson, ed) On Sense and Direct Reference: Readings in the Philosophy of Language (McGraw-Hill, 2007). This paper motivates (and gives a fairly gentle introduction to) a two-dimensional approach through the defense of a Fregean conception of meaning. I articulate some Fregean theses about sense, develop an intensional account of sense on which it is constitutively connected to epistemic possibility, and use this account to deal with various objections to Fregean views. Along the way, the two-dimensional framework as I understand it emerges. There have been discussions of this paper by Alex Byrne and Jim Pryor and Diego Marconi, among others. [pdf] [philpapers]

Co-authored with Frank Jackson. Philosophical Review, 110:315-61, 2001. This paper is a reply to Ned Block and Robert Stalnaker’s paper “Conceptual Analysis, Dualism, and the Explanatory Gap”. It doesn’t presuppose knowledge of that paper. It defends from first principles the thesis that there is an a priori entailment from microphysical and phenomenal truths (plus or minus a bit) to macroscopic truths; it addresses Block and Stalnaker’s objections to this thesis; and finally argues that a priori entailment is required for reductive explanation and for physicalism. The paper appears in Philosophical Review 110:315-61, 2001. There have been a number of replies, e.g. by Peter Carruthers, Joe Levine, and Laura Schroeter. A number of the ideas and argument here are developed further in Constructing the World. [pdf] [philpapers]

In (Q. Smith & A. Jokic, eds) Consciousness: New Philosophical Perspectives. Oxford University Press, 2003. This long paper has two halves. The first half gives an account of phenomenal concepts and phenomenal beliefs, on which their content is partly constituted by the quality of an experience. The second half applies this account to epistemological issues: e.g. arguing for a limited incorrigibility thesis, defending a sort of foundationalism about phenomenal knowledge, defending the phenomenal realist from certain epistemological problems, and addressing the “Myth of the Given”. [pdf] [philpapers]

In (T. Gendler & J. Hawthorne, eds) Conceivability and Possibility, pp. 145-200 (Oxford University Press, 2002). This paper distinguishes a number of notions of conceivability (ideal vs prima facie, positive vs negative, primary vs secondary) and argues for a link between some of them and metaphysical possibility. [html] [philpapers]

In (T. Metzinger, ed) Neural Correlates of Consciousness: Empirical and Conceptual Issues. MIT Press, 2000. Reprinted in (A. Noe & E. Thompson, eds) Vision and Mind: Selected Readings in the Philosophy of Perception (MIT Press, 2003). This paper, first presented at the 1998 ASSC conference on neural correlates of consciousness, focuses on neural correlates of consciousness, with reference to recent empirical work in the field (e.g. work in visual neuroscience by Logothetis, Milner and Goodale, and others). In particular it addresses what it means to be a neural correlate of consciousness, distinguishes different sorts of NCCs, and discusses the methodology of the search. It raises some questions about the conclusions that can be drawn from lesion studies. [pdf] [philpapers]

Consciousness Bulletin, University of Arizona, 1999. In this short paper I argue that the task of a science of consciousness is to connect third-person data about brain and behavior to first-person data about conscious experience, and I discuss the difficult question of how we might investigate and represent first-person data. I also discuss some specific issues about emotion. Written for a Tucson online workshop on emotion and consciousness. Most of the ideas were developed further in <../papers/scicon.pdf">How Can We Construct a Science of Consciousness. [html] [philpapers]

Unpublished. An extended outline of a talk I gave a couple of times in the late 1990s. I argue for a parallel between indicative and subjunctive conditionals, on the one hand, and the two dimensions of possibility in the 2-D framework. The standard contemporary analysis of possibility and necessity is grounded in subjunctive conditionals. I suggests that this is entirely arbitrary, and has had a distorting effect on many areas of philosophy. (Html here) [philpapers]

Philosophy and Phenomenological Research 59:473-93, 1999. This is my reply in a symposium on The Conscious Mind, which also included a precis. The commentators were Sydney Shoemaker, Brian Loar, Chris Hill & Brian McLaughin, and Stephen Yablo, all of whom take a “type-B materialist” position on which there is an epistemic gap between physical and phenomenal, but no modal gap. This gets quickly into issues about the 2-D analysis of a posteriori necessity, and whether there are “strong necessities” that escape it. I argue that there are not, and argue for a sort of modal rationalism. [html] [philpapers]

In (H. Jasper, L. Descarries, V. Castellucci, & S. Rossignol, eds) Consciousness: At the Frontiers of Neuroscience (Advances in Neurology, Vol. 77). Lippincott-Raven Press, 1998. An overview of the problems of consciousness in the context of science. There are a few original bits here but not much that isn’t done better elsewhere. [pdf] [philpapers]

In (S. Hameroff, A. Kaszniak, & A.Scott, eds.) Toward a Science of Consciousness II. MIT Press, 1998. This is a constructive analysis of the search for the "neural correlate of consciousness" (or the NCC, as it’s sometimes called). I argue that because we don’t have any way of detecting consciousness directly (i.e., we have no "consciousness meter"), the search is driven by pre-empirical bridging principles instead. I discuss some of these principles and draw some conclusions about the shape of the search. This paper is largely a transcript of my talk at the 1996 Tucson conference on consciousness, although some fun and games with a consciousness meter have been omitted (see the video.[pdf] [philpapers]

Journal of Consciousness Studies 4(1):3-46, 1997. Reprinted in (J. Shear, ed.), Explaining Consciousne\ ss: The Hard Problem. MIT Press, 1997. My lengthy reply to 25 articles commenting on “Facing Up to the Problem of Consciousness” All the papers and my reply were collected in the book, Explaining Consciousness: The Hard Problem (edited by Jonathan Shear), published by MIT Press in July 1997. [html] [philpapers]

Scientific American, 237(6):62-68, December 1995. Reprinted in (P. van Inwagen & D. Zimmerman, eds) Metaphysics: The Big Questions (Blackwell, 1998). Reprinted in (T. Schick & L. Vaughn, eds) Doing Philosophy: A Guide Through Thought-Experiments (Mayfield, 1999). Reprinted in (A. Damasio, ed) The Scientific American Book of the Brain (Lyons Press, 2001). Reprinted in (W. Lawhead, ed Philosophical Questions (McGraw-Hill, 2003). Reprinted in (L. Bonjour & A. Baker, eds) Philosophical Problems: An Annotated Anthology (Longman, 2004). Reprinted in (B. Beedles & M. Petracca, eds) Academic Communities/Disciplinary Conventions (Prentice-Hall, 2001). Reprinted in (B. Gertler & L. Shapiro, eds) Arguing About the Mind (Routledge, 2007). This is an especially accessible of “Facing Up the Problem of Consciousness”, with some pretty pictures. As with most Scientific American articles, much of this article was heavily revised by the editors, and all in all I prefer “Facing Up” as an introduction. But this version can be useful for people coming to the issue for the first time. [pdf] [philpapers]

Psyche, 2:11-20, 1995. This is a commentary on Roger Penrose’s book Shadows of the Mind, focusing on his attempt to use Gödel’s theorem to demonstrate the noncomputability of thought. I argue that the attempt is ultimately unsuccessful, but that there is a novel argument here that many commentators have overlooked, and that it raises many interesting issues. I also comment on his proposals concerning “the missing science of consciousness”. This paper appears in PSYCHE,2:11-20, 1995 in a symposium on Penrose’s book. Penrose replied in “Beyond the Doubting of a Shadow”. [html] [philpapers]

Co-authored with Andy Clark. Analysis 58:10-23, 1998. Reprinted in The Philosopher’s Annual, 1998. Reprinted in (D.J. Chalmers, ed) Philosophy of Mind: Classical and Contemporary Readings (Oxford University Press, 2002). Reprinted in (B. Gertler & L. Shapiro, eds) Arguing About the Mind (Routledge, 2007). Reprinted in (W. Lycan & J. Prinz, eds) Mind and Cognition, third edition (Blackwell, 2007). Reprinted in (A. Clark) Supersizing the Mind (Oxford University Press, 2008). Reprinted in (R. Menary, ed.) The Extended Mind (Ashgate, 2008). This paper advocates an “active externalism” where beliefs and other mental states are constituted by objects in the environment coupled to the organism (e.g. someone rearranging Scrabbles tiles on a rack or relying on a notebook as memory, for example). (Reconciling the externalism of this paper with the internalism of “The Components of Content” is left as an exercise for the reader.) This was reprinted in the 1998 The Philosophers’ Annual and by now is easily my most-cited paper. I recently found the first two drafts of this paper with handwritten comments all over them by Andy and me. [html] [philpapers]

In (D. Chalmers, ed) Philosophy of Mind: Classical and Contemporary Issues (OUP, 2002). This paper tries to do for thought what some of the other papers do for language: give an account of the contents of thought on which content is closely tied to reason and cognition. I decompose content into epistemic and subjunctive content, both of which are truth-conditional. Epistemic content is generally internal to a cognitive system, and governs rational relations between thoughts, so it can play the role of "narrow" or "cognitive" content. I apply this framework to a number of puzzles (Frege’s puzzle, Kripke’s puzzle, the problem of the essential indexical, the mode-of-presentation problem, etc.) in the philosophy of mind and the philosophy of language. The unpublished 1995 version of this paper was fairly widely cited; I later revised it for publication in my philosophy of mind anthology. The later version does some foundational things better, but in some respects the earlier version is more accessible. A closely related paper appeared as “The Nature of Narrow Content” in Philosophical Issues in 2003. Here are a couple of replies, by Stephen Schiffer (and my response) and by Alex Byrne. [pdf] [philpapers]

Times Literary Supplement\ , November 1994. This is a review of the first issue of the Journal of Consciousness Studies. [html] [philpapers]

Behavioral and Brain Sciences 20:148-9, 1997. Reprinted in (N. Block, O. Flanagan, and G. Guzeldere, eds.) The Nature of Consciousness (MIT Press, 1997). Here I argue that the cognitive correlate of conscious experience is direct availability for global control, and use this to shed light on a few vexing questions. This was written as a commentary on Ned Block‘s paper “On A Confusion about a Function of Consciousness"; Block’s reply is here. This paper overlaps to some extent with “On the search for a neural correlate of consciousness”. [html] [philpapers]

Journal of Consciousness Studies 2(3):200-19, 1995. Reprinted in (S. Hameroff, A. Kaszniak, & A.Scott, eds.) Toward a Science of Consciousness (MIT Press, 1996). Reprinted in J. Shear (ed.) Explaining Consciousness: The Hard Problem (MIT Press, 1997). Reprinted in J. Heil (ed.) Philosophy of Mind: A Guide and Anthology (Oxford University Press, 2003). Reprinted without attribution in (J. Vacca, ed) The World’s 20 Greatest Unsolved Problems (Prentice-Hall, 2004). Reprinted in (R. Carter) Exploring Consciousness (University of California Press, 2002). Reprinted in (M. Eckert, ed) Theories of Mind: Introductory Readings (Rowman and Littlefield). Reprinted (as “The Hard Problem of Consciousness” and “Naturalistic Dualism”) in (M. Velmans and S. Schneider, eds) The Blackwell Companion to Consciousness (Blackwell, 2007). This is the paper where I introduced the “hard problem” of consciousness. I distinguish between the easy problems and the hard problem, and I argue that the hard problem eludes conventional methods of explanation. I argue that we need a new form of nonreductive explanation, and make some moves toward a detailed nonreductive theory. This paper was based on a talk I gave at the 1994 Tucson conference on consciousness (see the video), and appeared in 1995 as part of a special issue of the Journal of Consciousness Studies. [pdf] [html] [philpapers]

You’re given two envelopes, and are told that one contains twice the amount in the other, but you aren’t told which is which. You tentatively decide to take envelope A, but then reason that there is a 50% chance that B contains twice A’s amount and a 50% chance that it contains half A’s amount, with an expected value of 1.25 times A’s amount overall, so it is in your interests to switch. But of course the same holds in reverse. What is going on? I give a detailed analysis of this "two-envelope" paradox, including a few interesting subtleties that are sometimes overlooked. I didn’t publish this as I now think the analysis is incomplete; in effect it solves the “numerical” paradox but not the “decision-theoretic” paradox. That’s addressed in my later The St. Petersburg Two-Envelope Paradox. [html] [ps] [philpapers]

Synthese 108:309-33, 1996. In an appendix to his book Representation and Reality, Hilary Putnam “proves” that every ordinary open system implements every finite automaton, so that computation cannot provide a nonvacuous foundation for the sciences of the mind. I analyze Putnam’s argument and find it wanting. The argument can be patched up to some extent, but this only points the way to a better definition of implementation (of combinatorial-state automata) that is invulnerable to such an objection. A couple of open questions remain, however. Synthese 108: 309-33, 1996. [html] [philpapers]

A Computational Foundation for the Study of Cognition. Journal of Cognitive Science 12:323-57, 2011. Section 2 was published as “On Implementing a Computation”, Minds and Machines 4:391-402, 1994. This paper addresses some key questions about computation and its role in cognitive science. I give an account of what it takes for a physical system to implement a given computation (in terms of abstract patterns of causal organization), and use this account to defend “strong artificial intelligence” and justify the centrality of computational explanation in cognitive science. This paper was written in 1993 but unpublished for many years (though section 2 appeared in “On Implementing a Computation” in Minds and Machines, 1994), and was finally published as the subject of a 2012 symposium in the Journal of Cognitive Science. [html] [philpapers].

In (T. Metzinger, ed.) Conscious Experience. Ferdinand Schoningh, 1995. Reprinted in (T. O’Connor & D. Robb, Philosophy of Mind: Contemporary Readings (Routledge, 2003). In this paper I use thought-experiments to argue that functional organization fully determines conscious experience. These thought-experiments involve the gradual replacement of neurons by silicon chips, and similar scenarios. I argue that if "absent qualia" or "inverted qualia" are possible, then phenomena I call "fading qualia" and "dancing qualia" will be possible; but I argue that it is very implausible that fading or dancing qualia are possible. The resulting position is a sort of "nonreductive functionalism". (There is also a German version entitled "Fehlende Qualia, schwindende Qualia, tanzende Qualia" (!), but it is not available online.) [html] [ps] [philpapers]

Behavioral and Brain Sciences, 1993. This is a commentary on Alvin Goldman’s piece "The Psychology of Folk Psychology", in Behavioral and Brain Sciences (June 1993). The paper contains a zombie thought-experiment or two, for people who like that sort of thing. [html] [philpapers]

Philosophical Psychology 6:305-19, 1993. I point out some structural problems with Fodor and Pylyshyn’s arguments against connectionism, and trace these to an underestimation of the role of distributed representation. I discuss some empirical results that have some bearing on Fodor and Pylyshyn’s argument. An earlier version was in the 1990 Proceedings of the Cognitive Science Society. See Murat Aydede’s “Connectionism and the Language of Thought” for some discussion. [pdf] [philpapers]

In The Cambridge Companion to Ockham, edited by Paul Spade (Cambridge, 1999). A rare venture into the history of philosophy. It was written when I was a graduate student in Paul Spade’s medieval logic class at Indiana. William of Ockham held that we think in a “mental language”, not unlike the language of thought that some contemporary philosophers believe in. The question arises whether the mental language can contain synonyms, or whether these are just artifacts of ordinary language. Most people have said no. Here I give some reasons to say yes. [html] [philpapers]

In (J. Dinsmore, ed.) The Symbolic and Connectionist Paradigms: Closing the Gap, pp. 25-48. Hillsdale, NJ: Lawrence Erlbaum, 1992. In this paper I analyze the distinction between symbolic and subsymbolic computation, and use this to shed some light on Searle’s “Chinese Room” argument and the associated argument that “syntax is not sufficient for semantics”. I argue that subsymbolic models may be less vulnerable to this argument. I no longer think this paper is very good, but perhaps the analysis of symbolic vs. subsymbolic computation is worthwhile. It appeared in The Symbolic and Connectionist Paradigms: Closing the Gap, edited by John Dinsmore, published by Lawrence Erlbaum in 1991. [pdf] [philpapers]

Co-authored with Bob French and Doug Hofstadter. Journal of Experimental and Theoretical Artificial Intelligence 4:185-211, 1992. Reprinted in (D. R. Hofstadter) Fluid Concepts and Creative Analogies. Basic Books. This paper argues that high-level perception is crucially involved in most cognitive processing. We mount a critique of the common approach of using “frozen”, hand-coded representations in cognitive modeling (exemplified by Langley and Simon’s BACON and Gentner’s Structure-Mapping Engine), and argue for a different approach in which representations are constructed and molded “on the fly”. There was a response by Forbus, Gentner, Markman, and Ferguson, as well as a commentary by Morrison and Dietrich. [pdf] [philpapers]

In Connectionist Models: Proceedings of the 1990 Summer School Workshop, 1990. San Mateo, CA: Morgan Kaufmann. I combine genetic algorithms and neural networks to show how learning mechanisms might evolve in a population of organisms that initially have no capacity to learn. The dynamics of a neural network’s cross-time development are specified in a genome, and phenotypes are selected for their ability to learn various tasks across a lifetime. Over many generations, sophisticated learning mechanisms are developed, including on occasion the well-known delta rule. [pdf] [philpapers]

Proceedings of the 12th Annual Conference of the Cognitive Science Society, 1990. Hillsdale, NJ: Lawrence Erlbaum. An earlier version of Connectionism and Compositionality: Why Fodor and Pylyshyn Were Wrong. The later version is better. [pdf]

Unpublished. Written when I was a graduate student at Indiana. It talks about the odd fact that even if consciousness is not reductively explainable, our claims about consciousness should be, and discusses various ways in which this tension might be resolved, eventually proposing a proto-theory of consciousness based on the notions of pattern and information. I no longer agree with everything in this paper, and it gets a bit wild toward the end, but it covers some interesting issues. I’ve never tried to publish it, but it is still one of my favorites and I’m intending to return to these themes at some point.[html] [ps] [philpapers]

Connection Science 2: 53-62, 1990. Reprinted in (N. Sharkey, ed) Connectionist Natural Language Processing (Intellect, 1992). In this paper I demonstrate that a connectionist network can be used to perform systematic structure-sensitive transformations on compressed distributed representations of compositional structures. Using representations developed by a Recursive Auto-Associative Memory (a model of Jordan Pollack‘s), a feedforward network learns to move systematically from representations of an active sentence to that of a corresponding passive sentence, and vice versa. This paper appeared in Connection Science in 1990. This line of research has since been extended by a number of others, e.g. in Lonnie Chrisman’s “Learning Recursive Distributed Representations for Holistic Computation”. [pdf] [philpapers]

Behavioral and Brain Sciences 13: 658-9, 1990. This is a commentary in a BBS symposium on Roger Penrose’s book The Emperor’s New Mind.