Michael Rescorla

The formal conception of computation (FCC) holds that computational processes are not sensitive to semantic properties. FCC is popular, but it faces well-known difficulties. Accordingly, authors such as Block and Peacocke pursue a ?semantically-laden? alternative, according to which computation can be sensitive to semantics. I argue that computation is insensitive to semantics within a wide range of computational systems, including any system with ?derived? rather than ?original? intentionality. FCC yields the correct verdict for these systems. I conclude that there is only one promising strategy for semantically-laden theorists: identify special computational systems that help generate their own semantic properties, and then show that computation within those systems is semantically-laden. Unfortunately, the few existing discussions that pursue this strategy are problematic

Turing computation over a non-linguistic domain presupposes a notation for the domain. Accordingly, computability theory studies notations for various non-linguistic domains. It illuminates how different ways of representing a domain support different finite mechanical procedures over that domain. Formal definitions and theorems yield a principled classification of notations based upon their computational properties. To understand computability theory, we must recognize that representation is a key target of mathematical inquiry. We must also recognize that computability theory is an intensional enterprise: it studies entities as represented in certain ways, rather than entities detached from any means of representing them

The central philosophical task posed by conventions is to analyze what they are and how they differ from mere regularities of action and cognition. Subsidiary questions include: How do conventions arise? How are they sustained? How do we select between alternative conventions? Why should one conform to convention? What social good, if any, do conventions serve? How does convention relate to such notions as rule, norm, custom, practice, institution, and social contract? Apart from its intrinsic interest, convention is important because philosophers frequently invoke it when discussing other topics. A favorite philosophical gambit is to argue that, perhaps despite appearances to the contrary, some phenomenon ultimately results from convention. Notable candidates include: property, government, justice, law, morality, linguistic meaning, necessity, ontology, mathematics, and logic

Dialectical egalitarianism holds that every asserted proposition requires defence when challenged by an interlocutor. This view apparently generates a vicious 'regress of justifications', since an interlocutor can challenge the premises through which a speaker defends her original assertion, and so on ad infinitum . To halt the regress, dialectical foundationalists such as Adler, Brandom, Leite, and Williams propose that some propositions require no defence in the light of mere requests for justification. I argue that the putative regress is not worrisome and that egalitarianism can handle it quite satisfactorily. I also defend a positive view that combines an anti-foundationalist conception of dialectical interaction with a foundationalist conception of epistemic justification.

This paper further develops the non-restrictive dialectical perspective. Many philosophers hold that truthfulness is somehow constitutive of assertion. I argue against this view while simultaneously attempting to ground truthfulness in assertion’s essential features. I argue that truthfulness is the prima facie best way to avoid decisive counter-arguments against what one says. Moreover, avoiding decisive counter-arguments is a constitutive goal of rational dialectic. Thus, while truthfulness is not constitutive of assertion, it is the rational default strategy for achieving a goal that is constitutive of assertion.

A striking thesis lies at the core of Davidson‟s philosophy: when we attribute intentional content to another creature‟s mental states and speech acts, we must treat the creature as largely conforming to our own rational norms. I will discuss how this thesis informs Davidson‟s treatment of rationality and intentionality. After reviewing some historical background, I present basic aspects of Davidson‟s position. I then examine various worries about the position. I conclude by highlighting some key Davidsonian insights into rationality.

Under what conditions does a physical system implement or realize a computation? Structuralism about computational implementation, espoused by Chalmers and others, holds that a physical system realizes a computation just in case the system instantiates a pattern of causal organization isomorphic to the computation’s formal structure. I argue against structuralism through counter-examples drawn from computer science. On my opposing view, computational implementation sometimes requires instantiating semantic properties that outstrip any relevant pattern of causal organization. In developing my argument, I defend anti-individualism about computational implementation: relations to the social environment sometimes help determine whether a physical system realizes a computation. 1 The Physical Realization Relation2 Semantics and Computational Implementation3 Conforming to Instructions4 Implementing a Computer Program4.1 The denotational semantics of Scheme4.2 Worries about intentionality4.3 Worries about the natural numbers5 Implementing a Machine Model6 Bounded Structuralism7 Triviality Arguments8 Anti-individualism about Computational Implementation