The Almagest, the Great Treatise on Astrology

Claudius Ptolemy was the leading ancient expert in astronomical theory. His mathematically sophisticated presentation of the heavenly system lived on for centuries. Alchemists availed themselves of Aristotelian chemistry, that is, theories of elemental transformation. Magic could be explained using ideas from Stoic and Platonist physics. We might expect that astrology would be a good match for Stoicism. But as it turns out, the Stoics were slow to embrace it with any enthusiasm.