The present chapter follows on neatly from 2.4 when the question of the cosmos' genesis was posed. The chapter heading formulates the subject in theological terms, even though there is no mention of a creating god in the body of the chapter itself. Most of the chapter argues for the sphericity of the cosmos and the circular revolution of the heavenly bodies (notably the sun). The final doxa is meant to introduce a contrast. Only the final phrase refers to a cosmological entity, i.e. the universe. As noted in sect. 1, the body of the chapter does not continue the theological emphasis of the title, but focuses first on the cosmic elements which first appeared in the cosmos' formation. A final aspect of the chapter that deserves to be examined is the use of the term xoaonoieiv in the title (it does not recur in the body of the chapter).Keywords: Aetius Placita; circular revolution; cosmic elements; heavenly bodies; sphericity; the sun; theological terms