As a tool for characterizing rational thought, logic cuts across many philosophical disciplines and lies at the core of mathematics and computer science. Drawing on Aristotle’s Organon, Russell’s Principia Mathematica, and other central works, this program tracks the evolution of logic, beginning with the basic syllogism. A sampling of subsequent topics includes propositional and predicate logic, Bayesian confirmation theory, Boolean logic, Frege’s use of variables and quantifiers, Gödel’s work with meta-mathematics, the Vienna Circle’s logical positivism, and the Turing machine. Commentary by Hilary Putnam, of Harvard University; NYU’s Kit Fine; and Colin McGinn, of Rutgers University, is featured. (43 minutes)