Philosophy 143

An introduction to the logical study of modality in its many forms: reasoning about necessity, knowledge, obligation, time, counterfactuals, provability, and other modal notions. Covers core concepts and basic metatheory of propositional modal logic, including relations to first-order logic; the basics of quantified modal logic; and selected philosophical applications ranging from epistemology to ethics, from metaphysics to mathematics. Pre-requisite: PHILOS 12A or equivalent (e.g., MATH 55 or CS 70).