Justin Clarke

In his influential book, _The Nature of Morality_, Gilbert Harman writes: “In explaining the observations that support a physical theory, scientists typically appeal to mathematical principles. On the other hand, one never seems to need to appeal in this way to moral principles.” What is the epistemological relevance of this contrast, if genuine? This chapter argues that ethicists and philosophers of mathematics have misunderstood it. They have confused what the chapter calls the _justificatory challenge_ for realism about an area, D—the challenge to justify our D-beliefs—with the _reliability challenge_ for D-realism—the challenge to explain the reliability of our D-beliefs. Harman’s contrast is relevant to the first, but not, evidently, to the second. One upshot of the discussion is that genealogical debunking arguments are fallacious. Another is that indispensability considerations cannot answer the Benacerraf–Field challenge for mathematical realism.

I want to motivate an account of what it is for an object to have a property, which may as well be called a deflationary view about properties. Such a view follows from a conception of predication I ground in the work of Donald Davidson, some of which remains unpublished. I claim that if we take seriously Davidson’s account of predication, by maintaining that sentences are the primary linguistic unit, we can define properties in terms of predicates. The aim of this paper is twofold. First, I argue that this account is present in Davidson’s systematic treatment of the problem of predication. Second, I claim that this account is serviceable and economical, as it can accommodate a wide scope of properties and abstract objects without appealing to entities such as truthmakers or joints in nature.

If certain versions of the correspondence theory of truth are correct, then truth can be informatively defined as correspondence to facts; facts would be truth-makers, and we could explain truth in terms of truth-bearers, correspondence, and truth-makers. I explain how slingshot arguments work generally, as collapsing arguments (regardless of their targets). Working through the slingshots of Davidson, and Gödel, I claim that Davidson’s slingshot involves dubitable premises, but that Gödel’s slingshot is terminal to certain versions of the correspondence theory, as it poses a fatal dilemma between what I call fact fission and fact fusion. My claim is that it is impossible to informatively define truth in terms of correspondence to facts.

Moral rationalism, the belief that acting contra a moral requirement is always irrational, is a strong claim; if true, seems to greatly reduce in scope the number of plausible moral theories due to what has been called the demandingness objection. One response to this consequence of moral rationalism has been to adopt moral anti-rationalism. Dale Dorsey thinks one can escape the demandingess objection with a weak form of anti-rationalism that still grants morality pride of place among normative systems. In this paper I’ll argue that the demandingness objection is a formidable challenge to moral rationalism, and that Dorsey is correct in arguing that his weak anti-rationalism neatly offers a way to evade the objection. I’ll maintain, however, that weak anti-rationalism opens theories up to another powerful objection, the permissiveness objection, which ought to lead someone comfortable abandoning moral rationalism to abandon weak anti-rationalism as well, accepting moral anti-rationalism.

In this dissertation I defend the claim, long held by Donald Davidson, that truth is a primitive concept that cannot be correctly or informatively defined in terms of more basic concepts. To this end I articulate the history of the primitive thesis in the 20th century, working through early Moore, Russell, and Frege, and provide improved interpretations of their reasons for advancing and eventually abandoning the primitive thesis. I show the importance of slingshot-style arguments in the work of Frege, Church, Davidson, and Gödel for resisting certain versions of the correspondence theory of truth. I argue that most slingshots fail to convincingly establish a collapsing conclusion, but that a Gödelian version of the slingshot is terminal to certain varieties of the correspondence theory of truth. I then provide a Davidsonian theory of truth and interpretation that is consistent with and makes use of the primitive thesis. Finally, I provide an account of predication, properties, and universals that I argue is both serviceable and consistent with Davidson’s overall program.