Reasons, basing, and the normative collapse of logical pluralism

Abstract

Logical pluralism is the view that there is more than one correct logic. A key objection to logical pluralism is that it collapses into monism. The core of the Collapse Objection is that only the pluralist's strongest logic does any genuine normative work; since a logic must do genuine normative work, this means that the pluralist is really a monist, who is committed to her strongest logic being the one true logic. This paper considers a neglected question in the collapse debate: what is it for a logic to do genuine normative work? As well as having wider upshot for the connection between logic and normativity, grappling with this question provides a new response to the Collapse Objection on behalf of the pluralist. I suggest that we should allow logics to generate pro tanto reasons in a way that bears not just on combinations of attitudes but on how an agent's attitudes are based on one another. This motivates adopting normative principles that allow the pluralist's weaker logics to earn their normative keep. Rather than being ad hoc, these principles capture a sense in which good reasoning goes beyond the consistency of an agent's attitudes. Good reasoning is also concerned with how an agent's attitudes are based on one another.

The normative role of logic for reasoning

“…In that previous work, I have also advocated for a pluralist position that supports the normativity of logic. This stance serves as my response to the ongoing debate surrounding logical pluralism and its compatibility with the normativity of logic which has garnered considerable attention recently (Blake-Turner, 2021;Blake-Turner & Russell, 2021;Ferrari & Moruzzi, 2020;Stei, 2020). Commonly known as the collapse problem, this debate posits that if there are many logics, then there must also be different normative guidelines.…”