The Chaldean Oracles are a revealed text written in the second century CE. They are attributed to Julian the Theurgist and his father, Julian the Chaldean. Julian the Theurgist served in the Roman army during the Marcomannic Wars during Marcus Aurelius’ campaign against the Quadi. It is claimed that during a severe drought, Julian caused a rainstorm which saved the expedition.
The circumstances surrounding the writing of the Chaldean Oracles are mysterious, the most likely explanation being that Julian uttered them after inducing a sort of trance akin to that of an oracle.
The Chaldean Oracles have a large amount of Hellenistic syncretism, more precisely Alexandrian; as practiced in the cultural melting-pot city that was Alexandria, and were credited with embodying many of the principal features of a “Chaldean philosophy”. They were held in the greatest esteem throughout Late Antiquity, with Iamblichus writing a now lost thirty-volume commentary on the Chaldean Oracles and Julian the Philosopher being well-versed in their teachings.
The word theourgia is coined in the Chaldean Oracles. While the Julians first use the word and develop its general use, it wasn’t until over a century later that theurgy was taken fully into Platonic practice.
Unfortunately the Chaldean Oracles merely survive in fragments; however they can be roughly pieced together. One of the best copies of the Chaldean Oracles is Ruth Majercik’s The Chaldean Oracles: Text, Translation and Commentary.
Flavius Claudius Iulianus Augustus, and Wilmer Cave. Wright. The works of emperor Julian. London: Heinemann etc., 1962.
Kupperman, Jeffrey S. Living Theurgy: A Course in Iamblichus’ Philosophy, Theology and Theurgy. London: Avalonia, 2014.
Shaw, Gregory. Theurgy and the soul: the Neoplatonism of Iamblichus. Second ed. Kettering, OH: Angelico Press, 2014.