Title: An Empirical and Normative Argument for Paraconsistency

Abstract:

Graham Priest has presented various arguments for paraconsistent logic. One line of argument is based on the alleged discrepancy between the principles of classical logic, in particular, ex contradictione quodlibet (A, ¬A ⊨ B for any A and B) and how we rationally reason. As such an argument requires a broadly empirical methodology, I call it an empirical argument for paraconsistent logic. Florian Steinberger has challenged this line of argument by claiming that it relies on the assumption that logic is normative and that no normative argument can be given in support of paraconsistent logic. In this paper, I will examine Steinberger’s challenge and argue that the challenge consists of problematic assumptions. I will, thus, defend Priest’s empirical and normative argument for paraconsistent logic.