Ryan Christensen

Dissertation

My dissertation is on propositions and truth. I defend robust theories of both, largely by clarifying and rejecting their nihilist and deflationary alternatives.

Nihilism (the label is Tarski’s) is an under-explored family of doctrines; it has often been conflated with deflationism. Many versions of nihilism have been developed, including fictional, performative, and pro-sentential theories. At its metaphysical core, nihilism is the view that there is no such property as truth, so the roles truth is thought to play (e.g., in epistemology and logic) must be played by something else; since I can find no suitable replacement for truth, I reject nihilism.

Deflationism is best understood as an attempt to answer the traditional problem, and in particular as deflating the correspondence theory. I examine various possible answers to the question of what deflationism comes to as a metaphysical position, and find there is no answer. Specifically, deflationism is the position that there is no meaningful definition or analysis or reduction of the property of truth. I argue that because of this, deflationism is too weak to explain the things that an inflationary theory can: why truth is valuable, for instance, or how truth is preserved in logical inference. Deflationism’s best chance lies in exploiting the dual nature of propositions as contentful objects, that can thus stand on either side of the mind/world divide. But even so, I argue, deflationism cannot explain everything truth was supposed to explain.

I explain and defend a thing-based correspondence theory of truth. Until the end of the nineteenth century, the correspondents in a correspondence theory were things, not facts. They were abandoned as not being able to handle the logical complexity of non-categorical propositions. I argue that if there are logically complex properties, we can dispense with facts and states of affairs, and thus avoid the apparently insurmountable obstacles faced by a fact-based correspondence theory. I take this view to be an extension of Aristotle’s theory of truth for categorical statements; the extension allows for propositions with a more complex ontology (about more than one object) and ideology (containing logically complex relations).

The view does require a view of propositions as structures of concepts, and I defend this view of propositions against deflationary and nihilist rivals. The view of propositions that seems most attractive to me has mental objects—concepts—as its basic components. I defend this view briefly against certain well-known objections. I argue that there is a vagueness in when concepts are considered “the same,” a vagueness inherited by the propositions. I conclude by showing how this view interacts with a puzzling requirement of propositional designators, which for certain purposes (such as certain brands of deflationism) need to be both rigid and epistemically transparent.

Minimal Liars

Proposing a new approach to the study of truth, Paul Horwich suggests that the nature of truth can be fully revealed by taking as axioms some class of propositions (Horwich himself takes the T biconditionals) from which all the facts about truth are supposed to follow. Because of the method’s unconventional logical character, the liar paradox presents an interesting case study. Prima facie it seems that any theory strong enough to imply all the facts about truth is strong enough to imply a contradiction, threatening to reduce the theory to inconsistency. Horwich’s own solution—restricting which T biconditionals count as axioms—cuts too deeply. Any restriction whatever leaves some truth facts unexplained, crippling the theory’s claim that it provides an adequate explanation of truth. Further, it is impossible to make a restriction in such a way that only the problematic axioms are excluded; indeed, the class of unexplained truths extends to include nearly all the central interesting facts. The modal strength required of the axioms (sufficient to force the ‘iff’ of the biconditionals to mark metaphysical equivalence) makes it impossible for the theory to explain the truth of generalizations (e.g., that everything Jones said is true). It may be that liar problems sink not only Horwich’s deflationary theory, but in general the axiomatic approach to the property of truth.