Two Notions of Circularity

Crispin Wright’s epistemic response to McKinsey’s paradox is to argue that introspective knowledge of the first premise fails to transmit across the semantic externalist entailment in the second premise to the conclusion that one has such untoward knowledge of the external world. This paper argues first that Stewart Cohen and Jonathan Vogel’s bootstrapping arguments suffer from a novel kind of epistemic circularity, which triggers failure of transmission but allows for the possibility of basic perceptual knowledge. It is then argued that McKinsey’s paradox falls out as a special case of this template for transmission failure. The circularity in play is semantic: the paradox illicitly imports semantically relevant properties of knowledge-individuating sources into the contents of the knowledge states that those sources individuate by instantiating those properties. Importantly, this diagnosis permits the possibility of basic introspective knowledge as propounded by Tyler Burge and other semantic externalists.