In amblyopia, abnormal visual experience during development leads to an enduring loss of visual acuity in adulthood. Physiological studies in animal models suggest that intracortical GABAergic inhibition may mediate visual deficits in amblyopia. To better understand the relationship between visual cortical γ-aminobutyric acid (GABA) and perceptual suppression in persons with amblyopia (PWA), we employed magnetic resonance spectroscopy (MRS) to quantify GABA levels in both PWA and normally-sighted persons (NSP). In the same individuals, we obtained psychophysical measures of perceptual suppression for (...) a variety of ocular configurations. In PWA, we found a robust negative correlation between the depth of amblyopia (the difference in visual acuity between the amblyopic and non-amblyopic eyes) and GABA concentration that was specific to visual cortex and was not observed in a sensorimotor cortical control region. Moreover, lower levels of visual cortical GABA were associated with weaker perceptual suppression of the fellow eye by the amblyopic eye and stronger suppression of the amblyopic eye by the fellow eye. Taken together, our findings provide evidence that intracortical GABAergic inhibition is an important component of the pathology of human amblyopia and suggest possible therapeutic interventions to restore vision in the amblyopic eye through enhancement of visual cortical GABAergic signaling in PWA. (shrink)

Byrne & Russon's target article displays all the difficulties encountered when one fails to take a methodological behaviourist approach to imitation. Their conceptual apparatus is grounded in a mixture of introspection and folk psychology. Their distinction between action-level and program-level imitation falters on goal imputation for sequential acts. In an alternative gradient descent model, behaviour can be simulated as a frustration/satisfaction gradient descent in the animal's “potentiality space,” as defined by knowledge, inventiveness, and the surrounding environment.

Like _Beyond All Appearances_,_ _which it supplements, Paul Weiss’s new book is a fundamental work which faces all the hard issues which are not only at the heart of philosophy but at the core of our entire culture. Readers of Mr. Weiss’s phenomenology of religion will need no introduction to this new work which expands and clari­fies many of the issues raised in _Beyond All Appearances. _However, no knowl­edge of Paul Weiss’s previous books is required to understand and (...) appreciate this brilliant new exposition. Weiss’s plain style makes his ideas accessible to all intelligent readers, whether or not they have been trained as professional philosophers. Here in _First Considerations _Mr. Weiss addresses himself to such topics as actuality, internalization, evidence, names, substance, being, natures and possibilities, existence, unity and the cosmos—issues which have engrossed him as a moral philosopher and meta­physician throughout his distinguished career. In his progress through the ideas and issues expounded in this new book Mr. Weiss is concerned with the human condition distinctive of this species of ours. Rigorously applied, his moral philosophy is as complete and thorough as that of any of the major thinkers, and provides as complete a guide as, for example, that of Buddhism. A highly original work, no doubt well in advance of current trends in philosophy, _First Considerations _will provoke further thought and discussion and will be regarded as a seminal work in modern philosophical approaches. (shrink)

2. Because of the possibility of lies, or the misuse of language, I believe that Professor Hempel's formulation of the problem of empirical certainty must be interpreted as a convenient abbreviation, in linguistic terms, of a question about beliefs. A complete formulation of the question would have to make some reference to the speaker's beliefs as he utters an "experiential statement.".

Eliminative materialism is the thesis that our common-sense conception of psychological phenomena constitutes a radically false theory, a theory so fundamentally defective that both the principles and the ontology of that theory will eventually be displaced, rather than smoothly reduced, by completed neuroscience. Our mutual understanding and even our introspection may then be reconstituted within the conceptual framework of completed neuroscience, a theory we may expect to be more powerful by far than the common-sense psychology it displaces, and more substantially (...) integrated within physical science generally. My purpose in this paper is to explore these projections, especially as they bear on (1) the principal elements of common-sense psychology: the propositional attitudes (beliefs, desires, etc.), and (2) the conception of rationality in which these elements figure. (shrink)

The problem of natural kinds forms the busy crossroads where a number of larger problems meet: the problem of universals, the problem of induction and projectibility, the problem of natural laws and de re modalities, the problem of meaning and reference, the problem of intertheoretic reduction, the question of the aim of science, and the problem of scientific realism in general. Nor do these exhaust the list. Not surprisingly then, different writers confront a different ‘problem of natural kinds,’ depending on (...) which background issue is for them the principal issue at stake. The issues of essentialism, meaning, and reference, for example, have tended to dominate recent discussions of natural kinds. But evidently these are only part of the puzzle. (shrink)

The problem of natural kinds forms the busy crossroads where a number of larger problems meet: the problem of universals, the problem of induction and projectibility, the problem of natural laws and de re modalities, the problem of meaning and reference, the problem of intertheoretic reduction, the question of the aim of science, and the problem of scientific realism in general. Nor do these exhaust the list. Not surprisingly then, different writers confront a different ‘problem of natural kinds,’ depending on (...) which background issue is for them the principal issue at stake. The issues of essentialism, meaning, and reference, for example, have tended to dominate recent discussions of natural kinds. But evidently these are only part of the puzzle. (shrink)

Paul M. Pietroski, University of Maryland I had heard it said that Chomsky’s conception of language is at odds with the truth-conditional program in semantics. Some of my friends said it so often that the point—or at least a point—finally sunk in.

The Mind-Body Problem Questions: What is the mind? What is its connection to the body? Most basic division of answers: Dualist and Materialist (or Physicalist) responses.

The emerging field of quantum mereology considers part-whole relations in quantum systems. Entangled quantum systems pose a peculiar problem in the field, since their total states are not reducible to that of their parts. While there exist several established proposals for modelling entangled systems, like monistic holism or relational holism, there is considerable unclarity, which further positions are available. Using the lambda operator and plural logic as formal tools, we review and develop conceivable models and evaluate their consistency and distinctness. (...) The main result is an exhaustive taxonomy of six distinct and precise models that both provide information about the mereological features as well as about the entangled property. The taxonomy is well-suited to serve as the basis for future systematic investigations. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:"The Fittest Man in the Kingdom":Thomas Reid and the Glasgow Chair of Moral PhilosophyPaul Wood (bio)Paul Wood Paul Wood is at the Department of History, University of Victoria, PO Box 3045, MS 7381, Victoria BC V8W 3P4 Canada. email: [email protected] August 1996Revised January 1997Notes. An earlier version of this paper was delivered at a plenary session of the 23rd International Hume Conference held at the University of (...) Nottingham. For comments and/or references, the author wishes to thank Roger Emerson, Carol Gibson-Wood, Knud Haakonssen, Ian Simpson Ross, Stephen Snobelen, M. A. Stewart, and the anonymous Hume Studies referees. For permission to cite and quote from manuscripts, he is grateful to the Keeper of the Manuscripts of Scotland as well as to the Librarians of Aberdeen University Library, Edinburgh University Library, Glasgow University Archives and Business Records Centre, Glasgow University Library (Department of Special Collections), the Mitchell Library Glasgow, and Dr. Williams' Library.1. Although little information survives regarding Law's teaching, we do know that he discussed Pufendorf in his classes; see Christine Mary King [Shepherd], "Philosophy and Science in the Arts Curriculum of the Scottish Universities in the Seventeenth Century," (Unpublished Ph.D. Dissertation, University of Edinburgh, 1974), 177. Carmichael's edition of Pufendorf first appeared in Glasgow in 1718, and a second edition was published in Edinburgh in 1724 while Hume was still a student there.2. The surviving correspondence between the two men from this period is to be found in The Letters of David Hume, ed. J.Y.T. Greig, 2 vols. (Oxford: Clarendon Press, 1932), I 32-35; 36-40; 45-48 (hereafter abbreviated as HL).3. The first detailed discussion of the 1745 election appeared in the introduction to David Hume, A Letter from a Gentleman to His Friend in Edinburgh, edited by Ernest C. Mossner and John V. Price (Edinburgh: Edinburgh University Press, 1967). This account has recently been challenged in Roger L. Emerson, "The 'Affair' at Edinburgh and the 'Project' at Glasgow: The Politics of Hume's Attempts to become a Professor," in Hume and Hume's Connexions, edited by M. A. Stewart and John P. Wright (Edinburgh: Edinburgh University Press, 1994), 1-22; and M. A. Stewart, The Kirk and the Infidel (Lancaster: Lancaster University Publications Office, 1995). For historically sensitive contextual analysis of Hume's philosophical relations with Hutcheson, see inter alia James Moore, "Hume and Hutcheson," in Stewart and Wright, 23-57, and M. A. Stewart, Warmth in the Cause of Virtue (Edinburgh: Edinburgh University Press, forthcoming).4. In January 1752, "Mr. Smith read an Account of some of Mr. David Hume's Essays on Commerce" to the Society, and Hume was elected a member in 1753; see Notices and Documents Illustrative of the Literary History of Glasgow, During the Greater Part of Last Century, edited by W. J. Duncan (Glasgow: T. D. Morison, 1886), 132-133. Hume's failed candidacy is discussed in Emerson, "The 'Affair' at Edinburgh," 14-16, and Ian Simpson Ross, The Life of Adam Smith (Oxford: Clarendon Press, 1995), 112-113. Smith's Glasgow colleague from 1751 to 1755, William Cullen, was also sympathetic to Hume's philosophy, as was John Millar, who was elected Professor of Law in 1761. On Cullen and Hume see J.R.R. Christie, "Ether and the Science of Chemistry: 1740-1790," in Conceptions of Ether: Studies in the History of Ether Theories 1740-1900, edited by G. N. Cantor and M.J.S. Hodge (Cambridge: Cambridge University Press, 1981), 90-96.5. David Hume to William Strahan, 26 October 1775, HL II 301.6. See, for example, The Works of Thomas Reid, D.D., edited by Sir William Hamilton, 4th ed. (Edinburgh: Maclachlan and Stewart, 1854), 30n; James McCosh, The Scottish Philosophy, Biographical, Expository, Critical, from Hutcheson to Hamilton (London: Macmillan, 1875), 36; James Veitch, "Philosophy in the Scottish Universities," Mind 2 (1877): 207-234 (209).7. John Rae, Life of Adam Smith (London and New York: Macmillan, 1895); William Robert Scott, Francis Hutcheson: His Life, Teaching and Position in the History of Philosophy (Cambridge: Cambridge University Press, 1900); idem., Adam Smith as Student and Professor (Glasgow: Jackson... (shrink)

Paul M. Pietroski, University of Maryland For any sentence of a natural language, we can ask the following questions: what is its meaning; what is its syntactic structure; and how is its meaning related to its syntactic structure? Attending to these questions, as they apply to sentences that provide evidence for Davidsonian event analyses, suggests that we reconsider some traditional views about how the syntax of a natural sentence is related to its meaning.

In _Matter and Consciousness_, Paul Churchland presents a concise and contemporary overview of the philosophical issues surrounding the mind and explains the main theories and philosophical positions that have been proposed to solve them. Making the case for the relevance of theoretical and experimental results in neuroscience, cognitive science, and artificial intelligence for the philosophy of mind, Churchland reviews current developments in the cognitive sciences and offers a clear and accessible account of the connections to philosophy of mind. For (...) this third edition, the text has been updated and revised throughout. The changes range from references to the iPhone's "Siri" to expanded discussions of the work of such contemporary philosophers as David Chalmers, John Searle, and Thomas Nagel. Churchland describes new research in evolution, genetics, and visual neuroscience, among other areas, arguing that the philosophical significance of these new findings lies in the support they tend to give to the reductive and eliminative versions of materialism. Matter and Consciousness, written by the most distinguished theorist and commentator in the field, offers an authoritative summary and sourcebook for issues in philosophy of mind. It is suitable for use as an introductory undergraduate text. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:"The Fittest Man in the Kingdom":Thomas Reid and the Glasgow Chair of Moral PhilosophyPaul Wood (bio)Paul Wood Paul Wood is at the Department of History, University of Victoria, PO Box 3045, MS 7381, Victoria BC V8W 3P4 Canada. email: [email protected] August 1996Revised January 1997Notes. An earlier version of this paper was delivered at a plenary session of the 23rd International Hume Conference held at the University of (...) Nottingham. For comments and/or references, the author wishes to thank Roger Emerson, Carol Gibson-Wood, Knud Haakonssen, Ian Simpson Ross, Stephen Snobelen, M. A. Stewart, and the anonymous Hume Studies referees. For permission to cite and quote from manuscripts, he is grateful to the Keeper of the Manuscripts of Scotland as well as to the Librarians of Aberdeen University Library, Edinburgh University Library, Glasgow University Archives and Business Records Centre, Glasgow University Library (Department of Special Collections), the Mitchell Library Glasgow, and Dr. Williams' Library.1. Although little information survives regarding Law's teaching, we do know that he discussed Pufendorf in his classes; see Christine Mary King [Shepherd], "Philosophy and Science in the Arts Curriculum of the Scottish Universities in the Seventeenth Century," (Unpublished Ph.D. Dissertation, University of Edinburgh, 1974), 177. Carmichael's edition of Pufendorf first appeared in Glasgow in 1718, and a second edition was published in Edinburgh in 1724 while Hume was still a student there.2. The surviving correspondence between the two men from this period is to be found in The Letters of David Hume, ed. J.Y.T. Greig, 2 vols. (Oxford: Clarendon Press, 1932), I 32-35; 36-40; 45-48 (hereafter abbreviated as HL).3. The first detailed discussion of the 1745 election appeared in the introduction to David Hume, A Letter from a Gentleman to His Friend in Edinburgh, edited by Ernest C. Mossner and John V. Price (Edinburgh: Edinburgh University Press, 1967). This account has recently been challenged in Roger L. Emerson, "The 'Affair' at Edinburgh and the 'Project' at Glasgow: The Politics of Hume's Attempts to become a Professor," in Hume and Hume's Connexions, edited by M. A. Stewart and John P. Wright (Edinburgh: Edinburgh University Press, 1994), 1-22; and M. A. Stewart, The Kirk and the Infidel (Lancaster: Lancaster University Publications Office, 1995). For historically sensitive contextual analysis of Hume's philosophical relations with Hutcheson, see inter alia James Moore, "Hume and Hutcheson," in Stewart and Wright, 23-57, and M. A. Stewart, Warmth in the Cause of Virtue (Edinburgh: Edinburgh University Press, forthcoming).4. In January 1752, "Mr. Smith read an Account of some of Mr. David Hume's Essays on Commerce" to the Society, and Hume was elected a member in 1753; see Notices and Documents Illustrative of the Literary History of Glasgow, During the Greater Part of Last Century, edited by W. J. Duncan (Glasgow: T. D. Morison, 1886), 132-133. Hume's failed candidacy is discussed in Emerson, "The 'Affair' at Edinburgh," 14-16, and Ian Simpson Ross, The Life of Adam Smith (Oxford: Clarendon Press, 1995), 112-113. Smith's Glasgow colleague from 1751 to 1755, William Cullen, was also sympathetic to Hume's philosophy, as was John Millar, who was elected Professor of Law in 1761. On Cullen and Hume see J.R.R. Christie, "Ether and the Science of Chemistry: 1740-1790," in Conceptions of Ether: Studies in the History of Ether Theories 1740-1900, edited by G. N. Cantor and M.J.S. Hodge (Cambridge: Cambridge University Press, 1981), 90-96.5. David Hume to William Strahan, 26 October 1775, HL II 301.6. See, for example, The Works of Thomas Reid, D.D., edited by Sir William Hamilton, 4th ed. (Edinburgh: Maclachlan and Stewart, 1854), 30n; James McCosh, The Scottish Philosophy, Biographical, Expository, Critical, from Hutcheson to Hamilton (London: Macmillan, 1875), 36; James Veitch, "Philosophy in the Scottish Universities," Mind 2 (1877): 207-234 (209).7. John Rae, Life of Adam Smith (London and New York: Macmillan, 1895); William Robert Scott, Francis Hutcheson: His Life, Teaching and Position in the History of Philosophy (Cambridge: Cambridge University Press, 1900); idem., Adam Smith as Student and Professor (Glasgow: Jackson... (shrink)

The philosophical problem of mental causation concerns a clash between commonsense and scientific views about the causation of human behaviour. On the one hand, commonsense suggests that our actions are caused by our mental states—our thoughts, intentions, beliefs and so on. On the other hand, neuroscience assumes that all bodily movements are caused by neurochemical events. It is implausible to suppose that our actions are causally overdetermined in the same way that the ringing of a bell may be overdetermined by (...) two hammers striking it at the same time. So how are we to reconcile these two views about the causal origins of human behaviour? One philosophical doctrine effects a nice reconciliation. Neuralism, or the token-identity theory, states that every particular mental event is a neurophysiological event and that every action is a physically specifiable bodily movement. If these identities hold, there is no problem of causal overdetermination: the apparently different causal pathways to the behaviour are actually one and the same pathway viewed from different perspectives. This attractively simple view is enjoying a recent revival in fortunes. (shrink)

In _ Plato's Camera_, eminent philosopher Paul Churchland offers a novel account of how the brain constructs a representation -- or "takes a picture" -- of the universe's timeless categorical and dynamical structure. This construction process, which begins at birth, yields the enduring background conceptual framework with which we will interpret our sensory experience for the rest of our lives. But, as even Plato knew, to make singular perceptual judgments requires that we possess an antecedent framework of abstract categories (...) to which any perceived particular can be relevantly assimilated. How that background framework is assembled in the first place is the motivating mystery, and the primary target, of Churchland's book. Unexpectedly, this neurobiologically grounded account of human cognition also provides a systematic story of how such low-level epistemological activities are integrated within an enveloping framework of linguistic structures and regulatory mechanisms at the social level. As Churchland illustrates, this integration of cognitive mechanisms at several levels has launched the human race on an epistemological adventure denied to all other terrestrial creatures. (shrink)

The ancient problem of the relationship of the continuous to the discrete, since its discovery by the Greeks, has posed a range of immensely fruitful challenges to both philosophical and mathematical thought, leading to a variety of mathematical and conceptual innovations whose positive development actively continues today. In this brief section introduction, I selectively outline some significant moments at which this problem has provided important historical occasions for concrete mathematical innovation as well as closely linked philosophical insights, before introducing the (...) particular contributions of the section authors to historical and contemporary research and practice into the nature and structure of the continuum, the construction of real numbers, the foundations of analysis, and the logical, set-theoretical, and computational underpinnings of the structure of continuously valued numbers in the most general sense, in both constructive and nonconstructivist contexts. (shrink)

The present essay is addressed simultaneously to two distinct audiences.

A study in the philosophy of science, proposing a strong form of the doctrine of scientific realism' and developing its implications for issues in the philosophy of mind.

"Churchland and Hooker have collected ten papers by prominent philosophers of science which challenge van Fraassen's thesis from a variety of realist perspectives. Together with van Fraassen's extensive reply... these articles provide a comprehensive picture of the current debate in philosophy of science between realists and anti-realists."—Jeffrey Bub and David MacCallum, Foundations of Physics Letters.

A Neurocomputationial Perspective illustrates the fertility of the concepts and data drawn from the study of the brain and of artificial networks that model the...

The doctrine that the character of our perceptual knowledge is plastic, and can vary substantially with the theories embraced by the perceiver, has been criticized in a recent paper by Fodor. His arguments are based on certain experimental facts and theoretical approaches in cognitive psychology. My aim in this paper is threefold: to show that Fodor's views on the impenetrability of perceptual processing do not secure a theory-neutral foundation for knowledge; to show that his views on impenetrability are almost certainly (...) false; and to provide some additional arguments for, and illustrations of, the theoretical character of all observation judgments. (shrink)

In _ Plato's Camera_, eminent philosopher Paul Churchland offers a novel account of how the brain constructs a representation -- or "takes a picture" -- of the universe's timeless categorical and dynamical structure. This construction process, which begins at birth, yields the enduring background conceptual framework with which we will interpret our sensory experience for the rest of our lives. But, as even Plato knew, to make singular perceptual judgments requires that we possess an antecedent framework of abstract categories (...) to which any perceived particular can be relevantly assimilated. How that background framework is assembled in the first place is the motivating mystery, and the primary target, of Churchland's book. Unexpectedly, this neurobiologically grounded account of human cognition also provides a systematic story of how such low-level epistemological activities are integrated within an enveloping framework of linguistic structures and regulatory mechanisms at the social level. As Churchland illustrates, this integration of cognitive mechanisms at several levels has launched the human race on an epistemological adventure denied to all other terrestrial creatures. (shrink)

This collection was prepared in the belief that the most useful and revealing of anyone's writings are often those shorter essays penned in conflict with...

For the uninitiated, there are two major tendencies in the modeling of human cognition. The older, tradtional school believes, in essence, that full human cognition can be modeled by dividing the world up into distinct entities -- called __symbol s__-- such as “dog”, “cat”, “run”, “bite”, “happy”, “tumbleweed”, and so on, and then manipulating this vast set of symbols by a very complex and very subtle set of rules. The opposing school claims that this system, while it might be good (...) at concluding that Paris is the capital of France or that there must be blood flowing in the left-rear leg of a cow, can never capture the full measure -- indeed, the essence -- of human cognition. For them, the essential features of cognition emerge from the combined effects of myriad, tiny actions far below the surface of consciousness. This is the camp to which Paul Churchland belongs. (shrink)

Paul M. Pietroski presents an ambitious new account of human languages as generative procedures that respect substantive constraints. He argues that meanings are neither concepts nor extensions, and sentences do not have truth conditions; meanings are composable instructions for how to access and assemble concepts of a special sort.

Early analytic philosophy -- Radical translation and intersubjective practice -- Critical outcome.

The Hurvich-Jameson (H-J) opponent-process network offers a familiar account of the empirical structure of the phenomenological color space for humans, an account with a number of predictive and explanatory virtues. Its successes form the bulk of the existing reasons for suggesting a strict identity between our various color sensations on the one hand, and our various coding vectors across the color-opponent neurons in our primary visual pathways on the other. But anti-reductionists standardly complain that the systematic parallels discovered by the (...) H-J network are just empirical correspondences, constructed post facto, with no predictive or explanatory purchase on the intrinsic characters of qualia proper. The present paper disputes that complaint, by illustrating that the H-J model yields some novel and unappreciated predictions, and some novel and unappreciated explanations, concerning the qualitative characters of a considerable variety of color sensations possible for human experience, color sensations that normal people have almost certainly never had before, color sensations whose accurate descriptions in ordinary language appear semantically ill-formed or even self-contradictory. Specifically, these "impossible" color sensations are activation-vectors (across our opponent-process neurons) that lie inside the space of neuronally possible activation-vectors, but outside the central 'color spindle' that confines the familiar range of sensations for possible objective colors. These extra-spindle chimerical-color sensations correspond to no reflective color that you will ever see objectively displayed on a physical object. But the H-J model both predicts their existence and explains their highly anomalous qualitative characters in some detail. It also suggests how to produce these rogue sensations by a simple procedure made available in the latter half of this paper. The relevant color plates will allow you to savor these sensations for yourself. (shrink)