Rivalry, Normativity, and the Collapse of Logical Pluralism

Abstract

Logical pluralism is the view that there is more than one correct logic. This very general characterization gives rise to a whole family of positions. I argue that not all of them are stable. The main argument in the paper is inspired by considerations known as the “collapse problem”, and it aims at the most popular form of logical pluralism advocated by JC Beall and Greg Restall. I argue that there is a more general argument available that challenges all variants of logical pluralism that meet the following three conditions: (i) that there are at least two correct logical systems characterized in terms of different consequence relations, (ii) that there is some sort of rivalry among the correct logics, and (iii) that logical consequence is normative. The hypothesis I argue for amounts to conditional claim: If a position satisfies all these conditions, then that position is unstable in the sense that it collapses into competing positions.