For scholars in the European Middle Ages, Isidore, bishop of Seville (560? ― 636) was one of the most influential authorities for understanding the natural world. Isidore’s On the Nature of Things is the first work on natural science by a Christian author that is not a commentary on the creation story in Genesis. Instead, Isidore adopted a classical model to describe the structure of the physical cosmos, and discuss the principles of astronomy, physics, geography, meteorology and time-reckoning. Into this framework he incorporated an eclectic array of ancient and patristic erudition. The fact that On the Nature of Things presents an essentially Greco-Roman picture of the universe, but amplified with Christian reflections and allegories, played a crucial role in the assimilation of ancient science into the emerging culture of the Middle Ages. It exerted a deep and long-lasting influence on scholars like Bede, one of whose earliest works was an adaptation of On the Nature of Things.
On the Nature of Things provides a new window into vital intellectual currents, as yet largely unexplored, flowing from Visigothic Spain into Celtic Ireland, Anglo-Saxon England, and Merovingian France. This is the first translation of this work into English. The introduction places the work in the context of Isidore's milieu and concerns, and traces the remarkable diffusion of his book. A chapter-by-chapter commentary explains how Isidore selected and transformed his source material, and added his own distinctive features, notably the diagrams that gave this work its medieval name The Book of Wheels (Liber rotarum).
Calvin B. Kendall is Emeritus Professor of English, University of Minnesota. His many books include The Allegory of the Church: Romanesque Portals and Their Verse Inscriptions (University of Toronto Press 1998) and (with Faith Wallis) Bede: On the Nature of Things and On Times (Liverpool University Press 2010).
Faith Wallis is Professor Emerita at McGill University in Montreal. Her research focuses on the textual and manuscript transmission of medical and scientific knowledge in the Middle Ages. Her many books include Bede: Commentary on the Gospel of Luke (with Calvin B. Kendall, 2024), Isidore of Seville: On the Nature of Things (2016), Bede: Commentary on Revelation (2013), all in the Liverpool University Press Translated Texts for Historians series.