Richard Rufus, a thirteenth-century philosopher and theologian, was among the first European medieval authors to study Aristotelian metaphysics, epistemology, and natural philosophy. His lectures on the so-called libri naturales date from a period shortly after the effective lapse of the ban on teaching them in 1231 and are among the earliest European commentaries on those works. In 1238, after writing treatises against Averroes and lecturing on Aristotle—at greatest length on the Metaphysics—he joined the Franciscan Order, left Paris, and became a theologian.

Rufus's lectures on Peter Lombard's Sentences were the first presented by an Oxford bachelor of theology. Greatly influenced by Robert Grosseteste, Rufus's Oxford lectures were devoted in part to a refutation of Richard Fishacre, the Dominican master who first lectured on the Sentences at Oxford.

Rufus's Oxford lectures were employed as a source by St. Bonaventure, whose lectures on the...