Gödelian Equivalence

Abstract

AbstractChs. 9 (and 8) convert the two basic forms of slingshot (collapsing) argument—one used by Alonzo Church, W. V. Quine, and Donald Davidson, the other by Kurt Gödel—into knock‐down deductive proofs that Donald Davidson's and Richard Rorty's cases against facts and the representation of facts are unfounded, and their slingshot arguments for discrediting the existence of facts unsatisfactory. The proofs are agnostic on key semantic issues; in particular, they assume no particular account of reference and do not even assume that sentences have references. Using the same procedure as in Chs. 8 and 9 shows that a slingshot argument engendered by Gödel's suggestions can be converted into a proof that delivers an exacting constraint on non‐extensional discourse—the Descriptive Constraint—and that is more general than anything Gödel appears to have had in mind. The proof of this constraint is constructed without appeal to logical equivalences, without assuming that a semantic theory must treat sentences as having references, without presupposing anything contentious about the semantics of singular terms, and without commitment to any particular semantics for definite descriptions. A constraint on facts, situations, states of affairs, and propositions—indeed on anything that is expressed or represented sententially—drops out as a trivial consequence of a constraint on non‐extensional discourse. The three sections of the chapter are: Principles of Conversion for Descriptions; Gödel's Proof in Quinean Format; and A Stronger Slingshot?