John Duns Scotus began his Parisian lectures on Peter Lombard's Sentences during the course of the academic year 1302-1303. He was forced to leave Paris in June of 1303 due to a dispute between King Philip IV of France and Pope Boniface VIII. Although there is still some disagreement as to when Scotus returned to Paris (in the fall of 1303, the spring of 1304, or even later in 1304), there is less disagreement about when he lectured on Book IV of the Sentences.1 He began in the spring of 1303 and completed his lectures on Book IV either in the fall of 1303 or the following spring of 1304.