Since its completion in 1267, Roger Bacon's Opus Maius has received only intermittent critical attention from medieval intellectual historians. In the more than seven centuries since Bacon first transmitted the Opus Maius to Clement IV, only a few editions of Bacon's "greater work" have appeared, separated by many years. In 1928, Robert Belle Burke completed the only full translation of the Opus Maius. Although Burke's work represents the only consolidated attempt to translate the Opus Maius into English, it has notable weaknesses. Like all translations it has fallen prey to the dynamism of language, but it also suffers from its translator's intent, as Burke primarily intended his translation to offer a means of teaching and learning the Latin language, with the mathematical content of Bacon's treatise being of secondary concern for Burke.

The ambitious content of Bacon's Opus Maius spans the spectrum of medieval thought, so neglecting or deemphasizing its intellectual contribution and value does violence to the work's reception. Part IV, Bacon's discussion of mathematics, most effectively illustrates the connections he perceived between the various spheres in the medieval intellectual universe, so the negative effects to strictly adhere to the structure of Bacon's Latin rather than emphasize the breadth and scope of his mathematical thought, is most keenly felt here. In this dissertation, I offer a new translation of Part IV of Roger Bacon's Opus Maius that addresses the concerns presented by Burke's translation and provides scholars with an accessible and readable text that opens up the richness and complexity of his mathematical thought. As Burke includes neither notes nor commentary, I present Bacon's mathematical ideas within the political, religious, and intellectual contexts of the thirteenth century.