Page "Eudoxus of Cnidus" Paragraph 32

A general idea of the content of On Speeds can be gleaned from Aristotle's Metaphysics XII, 8, and a commentary by Simplicius of Cilicia ( 6th century CE ) on De caelo, another work by Aristotle.

According to a story reported by Simplicius, Plato posed a question for Greek astronomers: " By the assumption of what uniform and orderly motions can the apparent motions of the planets be accounted for?

" ( quoted in Lloyd 1970, p. 84 ).

Plato proposed that the seemingly chaotic wandering motions of the planets could be explained by combinations of uniform circular motions centered on a spherical Earth, apparently a novel idea in the 4th century.