The Place of Poetry in Sacrobosco’s Sphere: Astronomy and Interpretation

This article explores the connection between astronomy and literature in Johannes Sacrobosco’s Tractatus de sphera, an introductory astronomy textbook of the thirteenth century. The Tractatus de sphera includes twenty quotations from classical poetry as part of its teaching. Many of these passages enter Sacrobosco’s text knit together with material from commentaries, and the hermeneutical approaches of commentators help determine the role poetry plays in the teaching of astronomy. Two commentaries in particular inform the Tractatus de sphera, whether directly or indirectly: Servius’s commentary on Virgil’s Georgics and Arnulf of Orléans’s commentary on Lucan’s Pharsalia. Each commentary serves Sacrobosco differently. Whereas Servius supplies Sacrobosco with a taxonomy for organizing astronomical phenomena found in poetry, Arnulf engages with issues of astronomical visualization and literary cartography. In both cases, however, Sacrobosco uses poetry in symbiotic relation with commentary. He quotes verse in the context of acts of interpretation. For Sacrobosco, commentary provides a medium where word and world can meet and be reconciled with one another.