There has been preserved, however, in the writings of the Neo-Platonists a collection of passages known as the Zoroastrian Logia or Chaldean Oracles[1322] and which “present ... a heterogeneous mass, now obscure and again bombastic, of commingled Platonic, Pythagorean, Stoic, Gnostic, and Persian tenets.”[1323] Not only are these often cited by the Neo-Platonists, but Porphyry, Iamblichus, and Proclus composed commentaries upon them.[1324] Some think that these citations and commentaries have reference to a single work put together by Julian the Chaldean in the period of the Antonines. This “mass of oriental superstitions, a medley of magic, theurgy, and delirious metaphysics,”[1325] was reverenced by the Neo-Platonists of the following centuries as a sacred authority equal to the _Timaeus_ of Plato. Our next chapter will therefore deal with the writings of the Neo-Platonists upon whom this spurious mystic literature had so much influence. CHAPTER XI NEO-PLATONISM AND ITS RELATIONS TO ASTROLOGY AND THEURGY Neo-Platonism and the occult—Plotinus on magic—The life of reason is alone free from magic—Plotinus unharmed by magic—Invoking the demon of Plotinus—Rite of strangling birds—Plotinus and astrology—The stars as signs—The divine star-souls—How do the stars cause and signify?—Other causes and signs than the stars—Stars not the cause of evil—Against the astrology of the Gnostics—Fate and free-will—Summary of the attitude of Plotinus to astrology—Porphyry’s _Letter to Anebo_—Its main argument—Questions concerning divine natures—Orders of spiritual beings—Nature of demons—The art of theurgy—Invocations and the power of words—Magic a human art: theurgy divine—Magic’s abuse of nature’s forces—Its evil character—Its deceit and unreality—Porphyry on modes of divination—Iamblichus on divination—Are the stars gods?—Is there an art of astrology?—Porphyry and astrology—Astrological images—Number mysticism—Porphyry as reported by Eusebius—The emperor Julian on theurgy and astrology—Julian and divination—Scientific divination according to Ammianus Marcellinus—Proclus on theurgy—Neo-Platonic account of magic borrowed by Christians—Neo-Platonists and alchemy. [Sidenote: Neo-Platonism and the occult.]