Forget about the ‘correspondence theory of truth’
It’s true that cats purr iff it’s useful to believe that cats purr, and since these two biconditionals are meant to be a priori, and since It’s useful to believe that cats purr iff cats purr is manifestly not a priori, the redundancy theory and the pragmatic theory conflict. Likewise, mutatis mutandis, for the redundancy theory versus the coherence and epistemic theories; and for the coherence, pragmatic, and epistemic theories versus one another. The alleged conflict between the correspondence theory and the redundancy theory is different. The conflict is not with the positive part of the redundancy theory, the bundle of redundancy biconditionals such as (1). Taking (1) together with