In our previous round, Anthony Shiver (University of Georgia) tagged A.J. Cotnoir (University of St. Andrews). The game continues, as Cotnoir makes his move…

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What is the logic of negation? And how could disagreements over this question ever be genuine, and not — as Quine thought — amount to merely changing the subject? In his ‘A Modality Called Negation‘ forthcoming in Mind, Francesco Berto proposes a comprehensive theory of negation as a modal operator where accessibility between worlds represents ‘compatibility’. This semantic framework allows us to isolate key core features that any negation must have. Berto contends that there are a number of candidates for negation, and that disagreements over e.g. the law of excluded middle or dialetheism are substantive debates between interlocutors who share a single concept. The paper is clearly written, technically precise, and offers a promising resolution to a central debate in the philosophy of logic. Francesco Berto, you are it!