Julien Murzi

Murzi & Rossi (2020) put forward a recipe for generating revenge arguments against any non-classical theory of semantic notions that can recapture classical logic for a set of sentences X provided X is closed under certain classical-recapturing principles. More precisely, Murzi & Rossi show that no such theory can be non-trivially closed under natural principles for paradoxicality and unparadoxicality.

In a recent paper, Lucas Rosenblatt objects that Murzi & Rossi’s principles are not so natural, and that non-classical theories can express perfectly adequate, and yet unparadoxical, notions of paradoxicality.

I argue that Rosenblatt’s strategy effectively amounts to fragmenting the notion of paradoxicality, much in the way Tarski’s treatment of the paradoxes fragments the notion of truth. Along the way, I discuss a different way of resisting Murzi & Rossi’s revenge argument, due to Luca Incurvati and Julian Schlöder, that doesn’t fragment the notion of paradoxicality, but that effectively bans paradoxical instances of semantic rules within subproofs, on the assumption that they are not evidence-preserving.

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