To make progress on the problem of consciousness, we have to confront it directly. In this paper, I first isolate the truly hard part of the problem, separating it from more tractable parts and giving an account of why it is so difficult to explain. I critique some recent work that uses reductive methods to address consciousness, and argue that such methods inevitably fail to come to grips with the hardest part of the problem. Once this failure is recognized, the (...) door to further progress is opened. In the second half of the paper, I argue that if we move to a new kind of nonreductive explanation, a naturalistic account of consciousness can be given. I put forward my own candidate for such an account: a nonreductive theory based on principles of structural coherence and organizational invariance, and a double-aspect theory of information. (shrink)

This volume concerns the status and ambitions of metaphysics as a discipline.

Experiences and beliefs are different sorts of mental states, and are often taken to belong to very different domains. Experiences are paradigmatically phenomenal, characterized by what it is like to have them. Beliefs are paradigmatically intentional, characterized by their propositional content. But there are a number of crucial points where these domains intersect. One central locus of intersection arises from the existence of phenomenal beliefs: beliefs that are about experiences.

[[This paper appears in my anthology _Philosophy of Mind: Classical and Contemporary Readings_ (Oxford University Press, 2002), pp. 608-633. It is a heavily revised version of a paper first written in 1994 and revised in 1995. Sections 1, 7, 8, and 10 are similar to the old version, but the other sections are quite different. Because the old version has been widely cited, I have made it available (in its 1995 version) at http://consc.net/papers/content95.html.

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

Computation is central to the foundations of modern cognitive science, but its role is controversial. Questions about computation abound: What is it for a physical system to implement a computation? Is computation sufficient for thought? What is the role of computation in a theory of cognition? What is the relation between different sorts of computational theory, such as connectionism and symbolic computation? In this paper I develop a systematic framework that addresses all of these questions. Justifying the role of computation (...) requires analysis of implementation, the nexus between abstract computations and concrete physical systems. I give such an analysis, based on the idea that a system implements a computation if the causal structure of the system mirrors the formal structure of the computation. This account can be used to justify the central commitments of artificial intelligence and computational cognitive science: the thesis of computational sufficiency, which holds that the right kind of computational structure suffices for the possession of a mind, and the thesis of computational explanation, which holds that computation provides a general framework for the explanation of cognitive processes. The theses are consequences of the facts that (a) computation can specify general patterns of causal organization, and (b) mentality is an organizational invariant, rooted in such patterns. Along the way I answer various challenges to the computationalist position, such as those put forward by Searle. I close by advocating a kind of minimal computationalism, compatible with a very wide variety of empirical approaches to the mind. This allows computation to serve as a true foundation for cognitive science. (shrink)

Conceptual engineering is the design, implementation, and evaluation of concepts. Conceptual engineering includes or should include de novo conceptual engineering (designing a new concept) as well as conceptual re-engineering (fixing an old concept). It should also include heteronymous (different-word) as well as homonymous (same-word) conceptual engineering. I discuss the importance and the difficulty of these sorts of conceptual engineering in philosophy and elsewhere.

I present an argument for panpsychism: the thesis that everything is conscious, or at least that fundamental physical entities are conscious. The argument takes a Hegelian dialectical form. Panpsychism emerges as a synthesis of the thesis of materalism and the antithesis of dualism. In particular, the key premises of the causal argument for materialism and the conceivability argument for dualism are all accommodated by a certain version of panpsychism. This synthesis has its own antithesis in turn: panprotopsychism, the thesis that (...) fundamental physical entities are protoconscious, also accommodates the key premises. Panpsychism and panprotopsychism are synthesized under Russellian monism, and then face an antithesis, the combination problem. The question of whether there is a new synthesis remains open. (shrink)

This paper is a response to the 26 commentaries on my paper "Facing Up to the Problem of Consciousness". First, I respond to deflationary critiques, including those that argue that there is no "hard" problem of consciousness or that it can be accommodated within a materialist framework. Second, I respond to nonreductive critiques, including those that argue that the problems of consciousness are harder than I have suggested, or that my framework for addressing them is flawed. Third, I address positive (...) proposals for addressing the problem of consciousness, including those based in neuroscience and cognitive science, phenomenology, physics, and fundamental psychophysical theories. Reply to: Baars, Bilodeau, Churchland, Clark, Clarke, Crick & Koch, Dennett, Hameroff & Penrose, Hardcastle, Hodgson, Hut & Shepard, Libet, Lowe, MacLennan, McGinn, Mills, O'Hara & Scutt, Price, Robinson, Rosenberg, Seager, Shear, Stapp, Varela, Velmans. (shrink)

The easy problems of consciousness are those that seem directly susceptible to the standard methods of cognitive science, whereby a phenomenon is explained in terms of computational or neural mechanisms. The hard problems are those that seem to resist those methods. The easy problems are easy precisely because they concern the explanation of cognitive abilities and functions. Once we have specified the neural or computational mechanism that performs the function of verbal report, for example, the bulk of our work in (...) explaining reportability is over. Baars theory of cognitive accessibility addresses many aspects of human cognition and shows promise as a theory of awareness, the functional correlate of conscious experience, but an explanation of experience itself is not on offer. The key is the conceptual point that the explanation of functions does not suffice for the explanation of experience. (shrink)

Computation is central to the foundations of modern cognitive science, but its role is controversial. Questions about computation abound: What is it for a physical system to implement a computation? Is computation sufficient for thought? What is the role of computation in a theory of cognition? What is the relation between different sorts of computational theory, such as connectionism and symbolic computation? In this paper I develop a systematic framework that addresses all of these questions. Justifying the role of computation (...) requires analysis of implementation, the nexus between abstract computations and concrete physical systems. I give such an analysis, based on the idea that a system implements a computation if the causal structure of the system mirrors the formal structure of the computation. This account can be used to justify the central commitments of artificial intelligence and computational cognitive science: the thesis of computational sufficiency, which holds that the right kind of computational structure suffices for the possession of a mind, and the thesis of computational explanation, which holds that computation provides a general framework for the explanation of cognitive processes. The theses are consequences of the facts that computation can specify general patterns of causal organization, and mentality is an organizational invariant, rooted in such patterns. Along the way I answer various challenges to the computationalist position, such as those put forward by Searle. I close by advocating a kind of minimal computationalism, compatible with a very wide variety of empirical approaches to the mind. This allows computation to serve as a true foundation for cognitive science. (shrink)

Here the extension of a sentence token is a truth-value, the extension of a name is an individual, and so on. Scenarios are most often understood as centered possible worlds – i.e. ordered triples of worlds, individuals, and times - although they may also be understood in other ways.

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

The first two conferences and books have become touchstones for the field. This volume presents a selection of invited papers from the third conference.

The radical view, the view we’re kind of pushing, is that the iPhone can be seen literally as a part of my mind. I actually remember things: in virtue of this information being in the iPhone, it is part of my memory. The iPhone isn’t just a tool for my cognition, it’s part of my cognition.

This paper explores how an evolutionary process can produce systems that learn. A general framework for the evolution of learning is outlined, and is applied to the task of evolving mechanisms suitable for supervised learning in single-layer neural networks. Dynamic properties of a network’s information-processing capacity are encoded genetically, and these properties are subjected to selective pressure based on their success in producing adaptive behavior in diverse environments. As a result of selection and genetic recombination, various successful learning mechanisms evolve, (...) including the well-known delta rule. The effect of environmental diversity on the evolution of learning is investigated, and the role of different kinds of emergent phenomena in genetic and connectionist systems is discussed. (shrink)