Color-coordinate system from a 13th-century account of rainbows.

We present a new analysis of Robert Grosseteste’s account of color in his treatise De iride (On the Rainbow), dating from the early 13th century. The work explores color within the 3D framework set out in Grosseteste’s De colore [see J. Opt. Soc. Am. A 29, A346 (2012)], but now links the axes of variation to observable properties of rainbows. We combine a modern understanding of the physics of rainbows and of human color perception to resolve the linguistic ambiguities of the medieval text and to interpret Grosseteste’s key terms

The Fulfillment of Science: Nature, Creation and Man in the Hexaemeron of Robert Grosseteste

Robert Grosseteste’s commentary on the six days of creation, the Hexaemeron, is one of his most extensive and detailed theological works. Composed during his time as bishop of Lincoln, it draws on earlier lectures, notably those on Genesis, and his scientific treatises. In the Hexaemeron Grosseteste provides a powerful definition of theology, arguing that it should not be identified as a science, but in the course of this definition deploying Aristotelian definitions with great skill. The Hexaemeron displays to the full the depth of range of Grosseteste’s reading, and provides, in its commentary on creation, the fulfillment of his earlier work, placing investigation of natural phenomena in the service of exegesis. This paper will explore pertinent themes for Grosseteste’s use of his earlier writing, and the implications of their subsequent interpretation. Nature, Creation and their interpretation by human reason allow Grosseteste wide scope for commentary, all grounded in the proper subject of theology, the unifying work of Christ