Ptolemy’s Cosmology in Greek and Arabic

Ptolemy's Almagest (2nd century AD) is the most influential work of ancient and medieval astronomy. This work, however, does not tell us the full story about its author's views of the heavens. After completing the Almagest, Ptolemy turned his attention to a physical investigation of celestial motions. The result is the Planetary Hypotheses, a bold attempt to provide a celestial physics that coheres with the mathematical account of astronomical observations in his Almagest.

This book provides the first complete critical edition and English translation of the Arabic version of the Planetary Hypotheses, which is lost for the most part in its original Greek. It furthermore provides an extensive commentary on the whole work, which situates the Planetary Hypotheses within the context of its time and investigates philosophical ideas central to the work. These include the epistemic value of mathematics relative to natural philosophy, and the shape, number, and dynamics of the celestial bodies. The book also investigates the influence of the Planetary Hypotheses on a wide range of medieval Arabic astronomical and philosophical works from the 9th to the 13th century AD. The upshot is to establish the Planetary Hypotheses as a crucial text for understanding the history of philosophy and science from Greek antiquity to the Arabic Middle Ages

I Introduction

II Astronomy, Natural Philosophy, and the Physical Reality of the Celestial Bodies
III The Dynamics of Celestial Motions
IV Conclusion
V The Arabic Version of the Planetary Hypotheses: Edition and Translation
VI Commentary

Glossary
Bibliography
Index