Logics and Theories of Consequence

John Wigglesworth (Institute of Philosophy, LSE)

Thurs 13 Mar, 12.30pm IPLunchtime Seminar: Room 243, Senate House, Malet Street, WC1

Logics and Theories of Consequence
John Wigglesworth(IP & LSE)

Abstract:
A logic can be understood as a theory of consequence.  A logic tells us what follows from what.  Different logics give us different theories about what follows from what.  For example, classical logic says that P follows from ~~P, while intuitionist logic denies this.  These two theories disagree about what follows from what, and so they give different theories of consequence.  We look at the idea of logics as theories of consequence from the perspective of the philosophy of science.  The literature on scientific theories is split roughly into two camps: syntactic accounts and semantic accounts.  Any account of scientific theory one chooses should provide us with identity conditions on theories, telling us when two theories are the same.  We show that both syntactic accounts and semantic accounts give inadequate identity conditions for logics as theories of consequence.

Admission Free. All welcome.