Yu and your mind (Q1313375)

The author in chapter 3 of \textit{In contradiction} (1987; Zbl 0682.03002) and elsewhere, argues that the naive notion of proof is inconsistent. \textit{Q. Yu} in ``Consistency, mechanicalness and the logic of the mind'' [Synthese 90, 145-179 (1990; Zbl 0752.03002)], argues that this argument trades on a fallacy of ambiguity between two notions of proof. The present paper disputes this, arguing that a single notion of proof is used in the original argument and that, for this, the argument is sound.