Modal logic is the logic of possibility and necessity: a formal system for reasoning about what must be and what could be. Modal logics extend the languages of propositional and predicate logic with modal operators, allowing philosophers to formalize a range of questions about metaphysical possibility, knowledge and belief, obligation and permission, determinacy and indeterminacy, and more. This course is a first exploration into these formal systems, with an emphasis on the metaphysical foundations of modal logics in their various applications. Potential topics (with student input) include actualist interpretations of quantified modal logic, the Barcan formulas, inner and outer truth, counterpart theory, naming and reference, contingent identity, and logical normativity. No prior experience with modal logic is assumed, but students should have some background in formal propositional and predicate logic. Collaboration on problem sets and writing projects will be encouraged.
Grade received: A+