Mapping the Universe presents a multi-disciplinary and multi-author exploration of Robert Grosseteste's treatise On the Sphere. Composed probably in the second decade of the thirteenth century, On the Sphere is part of a series of works on natural phenomena Grosseteste wrote between c.1195 and c.1230. In this work the focus is on astronomy and geometry. Grosseteste moves through issues on the sphericity of the Earth, the movements of celestial bodies, especially the Sun and Moon (including their eclipses), how Earth's climate is affected by these bodies, and how time and the seasons are measured. Drawing on a wide range of sources from the ancient world translated into Latin from Greek and Arabic, Grosseteste's On the Sphere is based, fundamentally, on a discussion of not just how astronomy operates but why. Aristotle and Euclid are the principal framework for his reasoning and presentation. This volume includes an English translation of the treatise, an online celestial model to
consult alongside the text, commentary on its striking aspects such as precession and epicycles, discussion of the historical and intellectual context including Grosseteste's concurrent interests in pastoral care, and its illuminated versions. Presented by a team of medievalists and modern scientists, the volume uses this multi-disciplinary methodology to elucidate the treatise and showcase its originality.

Giles E. M. Gasper, Professor of High Medieval History, Durham University,Tom C. B. McLeish, Professor of Natural Philosophy, University of York,Sigbjørn Olsen Sønnesyn, Lecturer in Medieval Christianity, University of Bristol,Hannah E. Smithson, Professor of Experimental Psychology, University of Oxford

Giles E. M. Gasper is Professor of High Medieval History in the Department of History at Durham University and Deputy Executive Dean for Research, Arts and Humanities Faculty, Durham University.

Tom C. B. McLeish FRS is Professor of Natural Philosophy in the Department of Physics at the Centre for Medieval Studies and Humanities Research Centre at the University of York.

Sigbjørn Olsen Sønnesyn is Lecturer in Medieval Christianity, University of Bristol.




Hannah E. Smithson is Professor of Experimental Psychology, Department of Experimental Psychology, University of Oxford and Tutorial Fellow, Pembroke College, Oxford.

List of Figures
List of Bixes
List of Tables
List of Plates
Abbreviations and Short Titles
List of Contributors
Author Credits
Introduction, Giles E. M. Gasper, Tom C. B. McLeish, Sigbjørn Olsen Sønnesyn, and Hannah E. Smithson
1. On the Sphere and Locating Robert Grosseteste, Giles E. M. Gasper
2. Pastoral Care and MS Savile 21, Giles E. M. Gasper
3. On the Sphere: Manuscripts, Translation, Historiography, and Synopsis, Sigbjørn Olsen Sønnesyn
Latin Edition and English Translation of On the Liberal Arts, Cecilia Panti (Editor) and Sigbjørn Olsen Sønnesyn (Translator)
4. Commentary on the Model of the World Machine, Brian K. Tanner
5. Missing from the Map: Concepts, Learning, Arguments, and the Utility of Astronomy, Nader El-Bizri, Anne Lawrence-Mathers, C. Philipp E. Nothaft, Sigbjørn Olsen Sønnesyn, Tom C. B. McLeish, Jack Cunningham, and Giles E. M. Gasper
6. Astronomy as Art and Astronomy as Science, Sigbjørn Olsen Sønnesyn
7. On the Sphere: Structure, Scope, and Sources, Sigbjørn Olsen Sønnesyn
8. Trepidation or Precession: The Turning Point in a Tradition, Tom C. B. McLeish and C. Philipp E. Nothaft
9. Epicycles, Clive R. Siviour and Tom C. B. McLeish
10. Illuminating On the Sphere, Laura Cleaver and Sarah Griffin
Concluding Reflections Giles E. M. Gasper, Tom C. B. McLeish, Sigbjørn Olsen Sønnesyn, and Hannah E. Smithson
The Virtual Celestial Model of On the Sphere Tom C. B. McLeish, Clive R. Siviour, and Jack Smith
Appendix 1
Commissio Cancellarii Universitatis Oxoniensis - Concerning the Commission to the Chancellor of the University of Oxford, Sigbjørn Olsen Sønnesyn and Giles E. M. Gasper
Appendix 2
Manuscripts of On the Sphere with Diagrams, Laura Cleaver and Sarah Griffin
Bibliography
Indices