Greg Restall (University of Melbourne): Proof identity, invariants and hyperintensionality

This talk is a comparison of how different approaches to hyperintensionality, aboutness and subject matter treat (classically) logically equivalent statements. I compare and contrast two different notions of subject matter that might be thought to be representational or truth first -- the subject matter introduced in Stephen Yablo's Aboutness (Princeton University Press, 2014), truthmakers conceived as situations, as elaborated in my "Truthmakers, Entailment and Necessity" (AJP, 1996), and I contrast this with the kind of inferentialist account of hyperintensionality arising out of the proof invariants I have explored in recent work.