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Michael Devitt

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Epistemology of Logic, Inference, Kripke, Lewis Carroll, Wittgenstein


In chapter 1 I introduce the main topics to be addressed and provide a summary of the dissertation. In chapter 2 I summarize Lewis Carroll's famous note "What the Tortoise Said to Achilles" and briefly review some of its most influential interpretations. The rest of the chapter is devoted to Kripke's unpublished interpretation of Carroll's note and the moral he draws from it: in section 2.2 I present and discuss what I call the "adoption problem" and in section 2.3 I clarify certain aspects of it. In chapter 3 I consider a modification of the original set up of the adoption problem in terms of rules of inference and argue that they cannot help us overcome it. I also compare Kripke's interpretation of Carroll with his famous interpretation of Wittgenstein in Wittgenstein on Rules and Private Language and discuss some points of connection between Wittgenstein's and Kripke's views on the relation between inferential acts and logical principles or rules.

The following three chapters are meant to discuss, in view of the adoption problem, versions of what have perhaps been the most influential proposals for the justification of basic logical principles: empiricism a la Quine, rational intuition, and concept-constitution. In chapter 4 I examine Kripke's use of the adoption problem to criticize Quine's views in "Two Dogmas of Empiricism." Since Kripke argues that Quine fails to see that the same objections he directs against Carnap in "Truth by Convention" can be applied to his own point of view in "Two Dogmas," I start with a brief review of Carnap's proposal and Quine's famous objection to it. I continue with Quine's "Two Dogmas" views, examine Kripke's criticisms, and claim that Quine's argument against Carnap should not be identified with Kripke's argument against Quine. I also distinguish what I call the "standard objection" to Quine's views from the objection based on the adoption problem and critically consider an attempt to overcome the latter by introducing some modifications to the Quinean system. In the final section I discuss Kripke's Carroll-inspired metaphysical argument against the Cartesian doctrine on the creation of eternal truths and propose a related epistemological version of the argument. In chapter 5 I introduce Kripke's intuition-based proposal for accounting for basic logical beliefs and inferences outlined in his talks and seminars and argue that it should be rejected because it overlooks his own adoption problem. I also note some possible variations of the proposal and claim that they do not fare better. In chapter 6 I focus on Boghossian's concept-constituting account. I discuss in detail his proposal for dealing with the justification of basic logical beliefs and some of the criticisms it has received. I argue that the main problem of this proposal is that it fails to accommodate the lessons that can be drawn from the adoption problem concerning the nature of inferring.

In chapter 7 I reconsider the significance of the adoption problem and focus on Ryle's famous distinction between knowing how and knowing that. In section 7.2 I argue that "intellectualism," the claim that knowledge how can be defined in terms of propositional knowledge (knowledge that), is not an option when it comes to basic deductive inferences and that some sort of knowing how is needed for an account of both propositional knowledge of basic logical principles and inferential uses (Kripke's interpretation of Carroll will play a key role in my argument). I then discuss two different ways of understanding the nature of basic inferences: a view in which deductive inferential rules are `hardwired' in us and govern our inferences without being represented, and a view where basic inferential acts are taken as a primitive ability, not internally informed by logical principles, though encouraged and improved by our direct immersion in inferential practices. I discuss some problems affecting the former proposal problems and leave the prospects of the latter as an open question. Finally, I argue that independently of what it is ultimately to be made of the nature of basic inferences, the adoption problem already indicates the need for rethinking the problem of the justification of basic logical principles and rules and what we hoped to achieve with its solution.

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