Duns Scotus (c. 1265-1308) is one of a handful of figures in the history of philosophy whose significance is truly difficult to overestimate. Despite an academic career that lasted barely two decades, and numerous writings left in various states of incompletion at his death, his thought has been profoundly influential in the history of western philosophy. The Questions on Aristotle's 'Perihermenias' is an early work, probably written at Oxford in the closing decade of the thirteenth century. The questions, which have come down to us in two sets ('Opus I' and 'Opus II'), most likely originated...