17 November 2022, The Utrecht Logic in Progress Series (TULIPS), Diego Tajer

Abstract: In a recent article, Gillian Russell (2020) claims that logic isn’t normative: according to her, the usual bridge principles are just derived from general principles for truth and falsity, such as “believe the truth” or “avoid falsity”. For example, we should believe tautologies just because we should believe the truth. Russell argues that this rejection of logical normativity can avoid the collapse objection for logical pluralism. In a different paper, Russell and Blake Turner (2021) defend a telic pluralism, where different logics may correspond to different epistemic aims, without assuming that logic is normative.

In a response to that paper, Stei (2020) claims that even if logic is normative in this weak derivative sense, the collapse objection re-emerges. His main point is that the collapse argument can still work even if the bridge principles are derivative (they just need to be true).

In this talk I will argue against Stei’s point. I will show that there is a possible strategy which maintains the derivative normativity of logic and provides a non-trivial logical pluralism. My proposal is different from the telic pluralism, for it does not depend on the epistemic aims of the agent. The key of my approach is the possibility of having different normative sources for different logics. I will argue that the distinction between classical and relevant logic can be understood in this way.

References:

Blake-Turner, C. and G. Russell, “Logical pluralism without the normativity”, Synthese 198, 2021, pp. 4859-4877.

Russell, G. “Logic isn’t normative”, Inquiry 63(3-4), 2020, pp. 371-388.

Stei, E. “Non-normative logical pluralism and the revenge of the normativity objection”, Philosophical Quarterly 70 (278), 2020, pp. 162–177.