Terry Horgan

  David Marr provided a useful framework for theorizing about cognition within classical, AI-style cognitive science, in terms of three levels of description: the levels of (i) cognitive function, (ii) algorithm and (iii) physical implementation. We generalize this framework: (i) cognitive state transitions, (ii) mathematical/functional design and (iii) physical implementation or realization. Specifying the middle, design level to be the theory of dynamical systems yields a nonclassical, alternative framework that suits (but is not committed to) connectionism. We consider how a brain's (or a network's) being a dynamical system might be the key both to its realizing various essential features of cognition — productivity, systematicity, structure-sensitive processing, syntax — and also to a non-classical solution of (frame-type) problems plaguing classical cognitive science

David Marr provided an influential account of levels of description in classical cognitive science. In this paper we contrast Marr'ent with some alternatives that are suggested by the recent emergence of connectionism. Marr's account is interesting and important both because of the levels of description it distinguishes, and because of the way his presentation reflects some of the most basic, foundational, assumptions of classical AI-style cognitive science . Thus, by focusing on levels of description, one can sharpen foundational differences between classicism and potential non-classical conceptions of mentality that might emerge under the rubric of connectionism

In this critical study I first summarize Crispin Wright's "Truth and Objectivity". Wright maintains (1) that truth- aptness of a given discourse is neutral about questions of realism and anti- realism concerning the discourse, but also (2) that such metaphysical questions largely turn on discourse- specific constraints governing the truth- predicate. I urge a distinction between (i) Wright's general approach to truth and objectivity, and (ii) his apparent inclination to implement and the approach by construing truth as a fundamentally epistemic notion. I argue against an epistemically reductive implementation, and I briefly sketch an alternative way to implement the book's core ideas

I distinguish two broad approaches to vagueness that I call "robust" and "wimpy". Wimpy construals explain vagueness as robust (i.e., does not manifest arbitrary precision); that standard approaches to vagueness, like supervaluationism or appeals to degrees of truth, wrongly treat vagueness as wimpy; that vagueness harbors an underlying logical incoherence; that vagueness in the world is therefore impossible; and that the kind of logical incoherence nascent in vague terms and concepts is benign rather than malignant. I describe some implications for logic, semantics, and metaphysics

J. L. Mackie argued that if there were objective moral properties or facts, then the supervenience relation linking the nonmoral to the moral would be metaphysically queer. Moral realists reply that objective supervenience relations are ubiquitous according to contemporary versions of metaphysical naturalism and, hence, that there is nothing especially queer about moral supervenience. In this paper we revive Mackie's challenge to moral realism. We argue: (i) that objective supervenience relations of any kind, moral or otherwise, should be explainable rather than sui generis; (ii) that this explanatory burden can be successfully met vis-à-vis the supervenience of the mental upon the physical, and in other related cases; and (iii) that the burden cannot be met for (putative) objective moral supervenience relations.

Josep Corbi raises several worries about the metaethical position that Mark Timmons and I have articulated and defended, which we call “nondescriptivist cognitivism.â€â€¦ His remarks prompt some points of clarification…. Timmons and I characterize descriptive content as “way-the-world-might-be†content. We maintain that “base case†beliefs—roughly, those non-evaluative and evaluative beliefs whose contents have the simplest kinds of logical form—are of two types: a non-evaluative belief is an is-commitment with respect to a core descriptive content, and an evaluative belief is an ought-commitment with respect to a core descriptive content. Core descriptive contents are those descriptive contents expressible by (nonevaluative) atomic sentences. Concerning the notion of a core descriptive content, Corbi says.