The Chaldean Oracles have survived as fragmentary texts from the 2nd century AD, and consist mainly of Hellenistic commentary on a single mystery-poem (which may have been compilations from several oracular sources, considering the random subject changes) that was believed to have originated in Chaldea. They appear to be a syncretic combination of Neoplatonic elements with others that were Persian or Babylonian in origin. Later Neoplatonists, such as Iamblichus and Proclus, rated them highly. The 4th-century Emperor Julian suggests in his Hymn to the Magna Mater that he was an initiate of the God of the Seven Rays, and was an adept of its teachings. When Christian Church Fathers or other Late Antiquity writers credit "the Chaldeans", they are probably referring to this tradition.
An analysis of the Chaldean Oracles demonstrates an inspiration for contemporary gnostic teachings: fiery emanations initiate from the transcendental First Paternal Intellect, from whom the Second Intellect, the Demiurge comprehends the cosmos as well as himself. Within the First Intellect, a female Power, designated Hecate, is, like Sophia, the mediating World-Soul. At the base of all lies created Matter, made by the Demiurgic Intellect. The matter farthest from the Highest God (First Father / Intellect) was considered a dense shell from which the enlightened soul must emerge, shedding its bodily garments. A combination of ascetic conduct and correct ritual are recommended to free the soul from the confines of matter and limitations, and to defend it against the demonic powers lurking in some of the realms between Gods and mortals.
The origins of the texts are unknown and mysterious. Some have claimed that the Chaldean Oracles, in the form in which they survive, were attributed to Julian the Theurgist and his father, Julian the Chaldean. Julian the Theurgist served in the Roman army during Marcus Aurelius' campaign against the Quadi. Julian claimed to have saved the Roman camp from a severe drought by causing a rainstorm. At least four other religious groups also claimed credit for this rainstorm. The circumstances surrounding the writing of the Oracles are mysterious, the most likely explanation being that Julian uttered them after inducing a sort of trance akin to that of the archaic oracles of Greece.