Albert of Saxony was one of the great logicians of the Middle Ages, on a par with William Ockham and John Buridan. The Twenty-Five Disputed Questions on Logic treat of central issues in logic, both then and now, such as the nature of meaning, of universals, of truth, and of tense and modality; and the quality and quantity of propositions, the role of negation, and the relations of contradiction and equivalence between them. Dr. Fitzgerald has studied Albert's work extensively, and previously edited the Twenty-Five Disputed Questions from the original manuscripts. This translation makes available for the first time in English this careful and exemplary examination of logical notions by an outstanding medieval thinker.