With Cleomedes' Lectures on Astronomy: A Translation of The Heavens, Alan C. Bowen and Robert B. Todd (hereafter B/T) have produced an exemplary and eminently useful translation, the first in English, of an important late Stoic pedagogical text on astronomy. By design this collaborative effort, based on Todd's 1990 Teubner of Cleomedes' Caelestia (Greek Meteora ), is intended both for "a varied readership … most of whom will not know the ancient languages" and especially for those whose interests lie in later Stoic philosophy, in ancient mathematical astronomy, or in the history of ancient astronomy proper (xii). Enhanced and enriched by an expansive introduction and a comprehensive running commentary on the translated text, this finely produced and affordable volume also features a substantial array of appended explanatory materials supplementary to the translation proper. Taken together, these features render the work a model of what a modern translation of an ancient technical work ought to be.

To appreciate fully the significance of the Caelestia a familiarity with the foundational concepts and background information provided in B/T's very detailed and lucidly organized Introduction (1–18) is essential. Divided into three sections, it will reward the patient reader's attention when encountering the translation itself. The first section, "Cleomedes' Date" (1–4), shows how the text's internal evidence is absolutely parmount. For example, in the absence of any external biographical data for its author, information drawn from The Heavens itself, both philosophical and astronomical, can establish only that Cleomedes was most likely active at some time during the first two centuries C.E. and that he was a professional teacher of Stoicism