This chapter argues that the cosmological doctors arose as the result of a much wider realignment in Classical Greek medicine. As some doctors grew increasingly concerned about the many variables that can change from one case to the next, they rejected older forms of diagnostic handbooks in favor of new methods for organizing medical knowledge. We see this anxiety over individual differences not only in the works of the cosmological doctors but also in texts such as On Regimen in Acute Diseases, Prognostic, Airs Waters Places, and the seven books of Epidemics. In all of these texts, medical inquiry is defined, quite generally, as a search for commonalities. Doctors in this period were gathering together multiple accounts, noting the similarities and differences between those accounts, and isolating high-level generalizations that can unite and govern them all. Although the cosmological doctors took their search for commonalities farther than some of their contemporaries might have been willing to follow, they nevertheless responded to the same pressures that transformed nearly all the medical literature that survives from this period.

Chapter 6 is the longest and the most elaborate chapter of De mundo. The topic of the chapter is God and his relation to the cosmos. This relation is explained by a sequence of no less than twelve analogies. It is argued that this proliferation of analogies is not an extravagant rhetorical profusion, but an elaborate explanatory device that affords the reader a fuller grasp of God: the sequence is composed in such a way that one analogy corrects or supplements another, thus building a complex conception of God in the mind of the reader. Following a detailed analysis of the analogies and their relations, the conception of God that emerges is discussed. It is argued that this conception is a distinctly Aristotelian one, albeit with some interesting elaborations and additions. The absence of Aristotle’s technical terms in the explanation of God and his relation to the world, it is suggested, is a consequence of the author’s attempt to make the Aristotelian conception of God attractive to non-Aristotelians as well. This contribution ends with a note on the use of quotations in Chapter 6, since nine out of the twelve quotations in De mundo are found in this one chapter.