Definition of "theurgy"

And from this he concludes that theurgy is a craft which accomplishes not only good but evil among gods and men; and that the gods also have passions, and are perturbed and agitated by the emotions which Apuleius attributed to demons and men, but from which he preserved the gods by that sublimity of residence, which, in common with Plato, he accorded to them.

1871, Augustine of Hippo, translated by Marcus Dods, The City of God, Book X, Chapter 9

This, again, in our popular theurgy, is materialised into the First person of the Trinity approving the Second, because he stands to the contract already in the Council of the Trinity passed.

1873, Matthew Arnold, Literature and Dogma, Chapter VII: The Testimony of Jesus to Himself

They therefore devoted themselves to examining the nature of the soul, and taught that its freedom consists in communion with God, to be achieved by absorption in a sort of ecstatic trance. This doctrine reaches its height in Plotinus, after whom it degenerated into magic and theurgy in its unsuccessful combat with the victorious Christianity.

1911, “Alexandrian School”, in Encyclopædia Britannica Eleventh Edition

For instance I have heard many people say that Dionysus was a mortal man because he was born of Semele, and that he became a god through his knowledge of theurgy and the Mysteries, and like our lord Heracles for his royal virtue was translated to Olympus by his father Zeus.

1913, Julian, translated by Emily Wilmer Cave Wright, Oration VII: To the Cynic Heracleios

Spiritual magic or theurgy was based on the idea that one could reach God in an ascent up the scale of creation made possible by a rigorous course of prayer, fasting and devotional preparation.

1971, Keith Thomas, Religion and the Decline of Magic, Folio Society, published 2012, page 261