Bob Alan Dumas
Notions of necessity and possibility, using the classical systems T, S4, and S5, and the syntax and the semantics (Kripke models) of these systems.
Modal logic is a logical system that permits an interpretation of the mode of truth. It allows a formal treatment of a range of philosophical problems for which propositional logic and first-order logic are not adequate. First-order logic is the logic of predicates. Modal logic is the logic of necessity and possibility. I assume that the student has completed Philosophy 120 (Introduction to Logic) or Math 310 (Mathematical Reasoning). After reviewing some necessary concepts of logic we will introduce classical systems of Modal Propositional Logic (K, T, S4, S5, B) and consider applications. We introduce the concept of logical completeness, and prove that some of the classical systems are complete. If time permits, we will continue our study of normal modal systems, including temporal interpretations of modal logic, incompleteness and compactness. We will attempt to strike a balance between philosophical relevance and formal rigor. The pace of the course will be determined by the desire to satisfy both of these objectives while allowing the students time to achieve a thorough understanding of the material. Homework will be assigned every other week. There will be a midterm and a final exam. Meets I&S or NW requirement. TEXT: A New Introduction to Modal Logic, Hughes and Creswell; Possibilities and Paradox, Beall and Vana Fraasen.
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General method of instruction
Class assignments and grading