Steven Horst

Over the past thirty years, it is been common to hear the mind likened to a digital computer. This essay is concerned with a particular philosophical view that holds that the mind literally is a digital computer (in a specific sense of “computer” to be developed), and that thought literally is a kind of computation. This view—which will be called the “Computational Theory of Mind” (CTM)—is thus to be distinguished from other and broader attempts to connect the mind with computation, including (a) various enterprises at modeling features of the mind using computational modeling techniques, and (b) employing some feature or features of production-model computers (such as the stored program concept, or the distinction between hardware and software) merely as a guiding metaphor for understanding some feature of the mind. This entry is therefore concerned solely with the Computational Theory of Mind (CTM) proposed by Hilary Putnam [1961] and developed most notably for philosophers by Jerry Fodor [1975, 1980, 1987, 1993]. The senses of ‘computer’ and ‘computation’ employed here are technical; the main tasks of this entry will therefore be to elucidate: (a) the technical sense of ‘computation’ that is at issue, (b) the ways in which it is claimed to be applicable to the mind, (c) the philosophical problems this understanding of the mind is claimed to solve, and (d) the major criticisms that have accrued to this view

Most contemporary philosophers of mind claim to be in search of a 'naturalistic' theory. However, when we look more closely, we find that there are a number of different and even conflicting ideas of what would count as a 'naturalization' of the mind. This article attempts to show what various naturalistic philosophies of mind have in common, and also how they differ from one another. Additionally, it explores the differences between naturalistic philosophies of mind and naturalisms found in ethics, epistemology, and philosophy of science. Section 1 introduces a distinction between two types of project that have been styled 'naturalistic', which I call philosophical naturalism and empirical naturalism . Sections 2 to 6 canvass different strands of philosophical naturalism concerning the mind, followed by a much briefer discussion of attempts to provide empirical naturalizations of the mind in Section 7 . Section 8 concludes the essay with a consideration of the relations between philosophical and empirical naturalism in philosophy of mind, arguing that at least some types of philosophical naturalism are incompatible with empirical naturalism.

Contemporary philosophers of mind tend to assume that the world of nature can be reduced to basic physics. Yet there are features of the mind consciousness, intentionality, normativity that do not seem to be reducible to physics or neuroscience. This explanatory gap between mind and brain has thus been a major cause of concern in recent philosophy of mind. Reductionists hold that, despite all appearances, the mind can be reduced to the brain. Eliminativists hold that it cannot, and that this implies that there is something illegitimate about the mentalistic vocabulary. Dualists hold that the mental is irreducible, and that this implies either a substance or a property dualism. Mysterian non-reductive physicalists hold that the mind is uniquely irreducible, perhaps due to some limitation of our self-understanding. In this book, Steven Horst argues that this whole conversation is based on assumptions left over from an outdated philosophy of science. While reductionism was part of the philosophical orthodoxy fifty years ago, it has been decisively rejected by philosophers of science over the past thirty years, and for good reason. True reductions are in fact exceedingly rare in the sciences, and the conviction that they were there to be found was an artifact of armchair assumptions of 17th century Rationalists and 20th century Logical Empiricists. The explanatory gaps between mind and brain are far from unique. In fact, in the sciences it is gaps all the way down.And if reductions are rare in even the physical sciences, there is little reason to expect them in the case of psychology. Horst argues that this calls for a complete re-thinking of the contemporary problematic in philosophy of mind. Reductionism, dualism, eliminativism and non-reductive materialism are each severely compromised by post-reductionist philosophy of science, and philosophy of mind is in need of a new paradigm. Horst suggests that such a paradigm might be found in Cognitive Pluralism: the view that human cognitive architecture constrains us to understand the world through a plurality of partial, idealized, and pragmatically-constrained models, each employing a particular representational system optimized for its own problem domain. Such an architecture can explain the disunities of knowledge, and is plausible on evolutionary grounds

  Over the past several decades, the philosophical community has witnessed the emergence of an important new paradigm for understanding the mind.1 The paradigm is that of machine computation, and its influence has been felt not only in philosophy, but also in all of the empirical disciplines devoted to the study of cognition. Of the several strategies for applying the resources provided by computer and cognitive science to the philosophy of mind, the one that has gained the most attention from philosophers has been the Computational Theory of Mind (CTM). CTM was first articulated by Hilary Putnam (1960, 1961), but finds perhaps its most consistent and enduring advocate in Jerry Fodor (1975, 1980, 1981, 1987, 1990, 1994). It is this theory, and not any broader interpretations of what it would be for the mind to be a computer, that I wish to address in this paper. What I shall argue here is that the notion of symbolic representation employed by CTM is fundamentally unsuited to providing an explanation of the intentionality of mental states (a major goal of CTM), and that this result undercuts a second major goal of CTM, sometimes refered to as the vindication of intentional psychology. This line of argument is related to the discussions of derived intentionality by Searle (1980, 1983, 1984) and Sayre (1986, 1987). But whereas those discussions seem to be concerned with the causal dependence of familiar sorts of symbolic representation upon meaning-bestowing acts, my claim is rather that there is not one but several notions of meaning to be had, and that the notions that are applicable to symbols are conceptually dependent upon the notion that is applicable to mental states in the fashion that Aristotle refered to as paronymy. That is, an analysis of the notions of meaning applicable to symbols reveals that they contain presuppositions about meaningful mental states, much as Aristotle's analysis of the sense of healthy that is applied to foods reveals that it means conducive to having a healthy body, and hence any attempt to explain mental semantics in terms of the semantics of symbols is doomed to circularity and regress. I shall argue, however, that this does not have the consequence that computationalism is bankrupt as a paradigm for cognitive science, as it is possible to reconstruct CTM in a fashion that avoids these difficulties and makes it a viable research framework for psychology, albeit at the cost of losing its claims to explain intentionality and to vindicate intentional psychology. I have argued elsewhere (Horst, 1996) that local special sciences such as psychology do not require vindication in the form of demonstrating their reducibility to more fundamental theories, and hence failure to make good on these philosophical promises need not compromise the broad range of work in empirical cognitive science motivated by the computer paradigm in ways that do not depend on these problematic treatments of symbols

It has recently been claimed (1) that mental states such as beliefs are theoretical entities and (2) that they are therefore, in principle, subject to theoretical elimination if intentional psychology were to be supplanted by a psychology not employing mentalistic notions. Debate over these two issues is seriously hampered by the fact that the key terms 'theoretical' and 'belief' are ambiguous. This article argues that there is only one sense of 'theoretical' that is of use to the eliminativist, and in this sense some kinds of "belief" (dispositional states, infra-conscious states and the Freudian unconscious) are indeed "theoretical" and hence possible candidates for elimination, while others (consciously occurring thoughts like judgements and perceptual Gestalten) are not theoretical and hence not candidates for elimination

Recent debates about the metaphysics of mind have tended to assume that inter-theoretic reductions are the norm in the natural sciences. With this assumption in place, the apparent explanatory gaps surrounding consciousness and intentionality seem unique, fascinating, and perhaps metaphysically significant. Over the past several decades, however, philosophers of science have largely rejected the notions that inter-theoretic reduction is either widespread in the natural sciences or a litmus for the legitimacy of the special sciences. If we adopt a post-reductionist philosophy of science, with a commitment to theory pluralism, the epistemic statuses of the standard positions in philosophy of mind (reductionism, non-reductive physicalism, dualism) are all significantly changed. Moreover, central problems of recent philosophy of mind – reducibility and the explanatory gap – seem themselves to be in need of rethinking if reductions are rare and the sciences have “explanatory gaps all the way down.” This article examines the prospects of the standard metaphysical positions, plus two types of pluralism, in light of post-reductionist philosophy of science.

The New Semantics (NS) introduced by Kripke and Putnam is often thought to block antiphysicalist arguments that involve an inference from an explanatory gap to a failure of supervenience. But this “NS Rebuttal” depends upon two assumptions that are shown to be dubious. First, it assumes that mental-kind terms are among the kinds of terms to which NS analysis is properly applied. However, there are important differences in this regard between the behavior of notions like ‘pain’ and notions like ‘water’, as Kripke himself has argued. Second, even on the assumption that NS analysis is appropriate to mental-kind terms, it is further assumed that this would block the anti-physicalist premise that an abiding and principled explanatory gap would entail a failure of metaphysical supervenience. But the paradigm examples of NS analysis show nothing of the sort. What they show is that there are a posteriori necessities (e.g., “water contains hydrogen”) that cannot be inferred from the sense of natural kind terms. But they do not show that such necessities cannot be derived from an adequate scientific understanding of the phenomena in question. Indeed, such derivations are often available with kinds like water, but seem unavailable with mental kinds like ‘pain’ and ‘belief’.

This book introduces an account of cognitive architecture, Cognitive Pluralism, on which the basic units of understanding are models of particular content domains. Having many mental models is a good adaptive strategy for cognition, but models can be incompatible with one another, leading to paradoxes and inconsistencies of belief, and it may not be possible to integrate the understanding supplied by multiple models into a comprehensive and self-consistent "super model". The book applies the theory to explaining intuitive reasoning and cognitive illusions and explores implications for epistemology, semantics, and disunity of science.

This article examines the notions of “intuitive” and “counterintuitive” beliefs and concepts in cognitive science of religion. “Intuitive” states are contrasted with those that are products of explicit, conscious reasoning. In many cases the intuitions are grounded in the implicit rules of mental models, frames, or schemas. I argue that the pathway from intuitive to high theological concepts and beliefs may be distinct from that from intuitions to “folk religion,” and discuss how Christian theology might best interpret the results of studies in cognitive psychology of religion.

Chalmers and others have argued that physicalist microexplanation is incapable of solving the ‘hard problem’ of consciousness. This article examines whether evolutionary accounts of the mind, such as those developed by Millikan, Dretske and Flanagan, can add anything to make up for the possible short falls of more reductionist accounts. I argue that they cannot, because evolutionary accounts explain by appeal to a selectional history that only comes into the picture if consciousness can first arise due to spontaneous mutation in some individual organism, and explaining this emergence of consciousness from DNA and embryology calls for precisely the kind of structurally-based supervenience account that Chalmers et al. have objected to. Not only does an evolutionary account not succeed where a reductionist account fails; the evolutionary account presupposes the possibility of a reductionist account

This book offers a sustained critique of the computational theory of mind that deserves the attention of those interested in the presuppositions and implications of computational psychology. Horst begins by laying out the theory, reconstructing its perceived role in vindicating intentional psychology, and recounting earlier critiques on which he builds. Part 2, the heart of the book, analyzes a notion central to CTM—that of a symbol—arguing that symbols are conventional. In Part 3 Horst applies the results of this analysis to CTM to diagnose a serious confusion in its account of semantic properties and the corresponding notion of mental representation. Part 4 offers an alternative perspective on computational psychology, suggesting a separation of the practice of computational psychology from the philosophical claims made by CTM.

This essay describes an approach to designing a course in philosophy as a way of life (PWOL) around a set of immersive “spiritual exercises” through which students might examine their desires, engaging students in a process of testing their own experience against philosophical theories and theories against their own experience. These are used to tie together the units of a course covering classical Western and Eastern philosophical traditions, and to supplement traditional philosophical analysis of texts and arguments with ways of exploring what it might be like to live as a Platonist, Stoic, or Confucian. The essay details several exercises, engages perspectives on PWOL from Pierre Hadot and John Cooper, and addresses the question of how to assess immersive exercises.

This essay describes an approach to designing a course in philosophy as a way of life (PWOL) around a set of immersive “spiritual exercises” through which students might examine their desires, engaging students in a process of testing their own experience against philosophical theories and theories against their own experience. These are used to tie together the units of a course covering classical Western and Eastern philosophical traditions, and to supplement traditional philosophical analysis of texts and arguments with ways of exploring what it might be like to live as a Platonist, Stoic, or Confucian. The essay details several exercises, engages perspectives on PWOL from Pierre Hadot and John Cooper, and addresses the question of how to assess immersive exercises.