Logic and Language

Mark Jago (Nottingham): Exact Truthmaking Logic

Speaker: Mark Jago (Nottingham)
Title: Exact Truthmaking Logic
Time: 16:00 - 17:30
Location: ILLC Seminar Room F1.15

The notion of exact truthmaking is central to the logic of truthmaking and to the project of giving semantics in terms of truthmakers. An exact truthmaker for A is a state α in virtue of which A is true, so that states with irrelevant parts do not count as exact truthmakers for A. This semantics produces a very unusual consequence relation, on which conjunctions do not entail their conjuncts. This feature makes the logic highly unusual and worth investigating on purely logical grounds. But the investigation of exact truthmaker logic also has interesting applications in metaphysics. Exact truthmaking logic has received very little attention in the technical literature. In this talk, I’ll set out systems of formal semantics for exact truthmaking. I'll give a representation theorem for entailment and a complete sequent-style proof system. I’ll finish by discussing applications of these semantic systems to various metaphysical debates about truthmaking. I’ll argue that truthmaking semantics help us to systematise philosophical intuitions about a number of important metaphysical concepts.