The logical calculus whose expressions are letters representing sentences or propositions, and constants representing operations on those propositions, to produce others of higher complexity. The operations include conjunction, disjunction, material implication and negation (although these need not be primitive: see Sheffer's stroke ). Propositional logic was partially anticipated by the Stoics but reached maturity only with the work of Frege, Russell, and Wittgenstein . See also logic, tautology, truth-function.
Philosophy dictionary. Academic. 2011.