This course explores non-classical logics and extensions to classical logic. Potential topic to be explored include: modal logic, higher-order logic, the logic of conditionals, many-valued logic, fuzzy logic, supervaluationism, intuitionist logic, and relevance logic. The course may also ask how the notion of entailment is best interpreted in such systems. Students are expected to already have a familiarity with classical propositional and first-order logic.