See also Invocation.
Theurgy means 'divine-working'. The first recorded use of the term is found in the mid-second century neo-Platonist work, the Chaldean Oracles. The source of Western theurgy can be found in the philosophy of late Neoplatonists, especially Iamblichus. In late Neoplatonism, the spiritual Universe is regarded as a series of emanations from the One. From the One emanated the Divine Mind (Nous) and in turn from the Divine Mind emanated the World Soul (Psyche). Neoplatonists insisted that the One is absolutely transcendent and in the emanations nothing of the higher was lost or transmitted to the lower, which remained unchanged by the lower emanations.
Plotinus urged contemplations for those who wished to perform theurgy, the goal of which was to reunite with The Divine (called henosis). Therefore, his school resembles a school of meditation or contemplation. Iamblichus of Calcis (Syria), a student of Porphyry (who was himself a student of Plotinus) taught a more ritualized method of theurgy that involved invocation and religious, as well as magical, ritual. Iamblichus believed theurgy was an imitation of the gods, and in his major work, On the Egyptian Mysteries, he described theurgic observance as "ritualized cosmogony" that endowed embodied souls with the divine responsibility of creating and preserving the cosmos.
Iamblichus' analysis was that the transcendent cannot be grasped with mental contemplation because the transcendent is supra-rational. Theurgy is a series of rituals and operations aimed at recovering the transcendent essence by retracing the divine 'signatures' through the layers of being. Education is important for comprehending the scheme of things as presented by Aristotle, Plato and Pythagoras but also by the Chaldaean Oracles. The theurgist works 'like with like': at the material level, with physical symbols and 'magic'; at the higher level, with mental and purely spiritual practices. Starting with correspondences of the divine in matter, the theurgist eventually reaches the level where the soul's inner divinity unites with The Divine.
The Emperor Julian the Apostate (332-363), embraced Neoplatonic philosophy and worked to replace catholic Christianity with a version of Neoplatonic paganism. Because of his death and the hold mainstream catholic and orthodox Christianity had over the empire at the time, this was ultimately unsuccessful, but he did produce several works of philosophy and theology, including a popular hymn to the sun. In his theology, Helios, the sun, was the ideal example of the perfection of the gods and light, a symbol of divine emanation. He also held the mother goddess Cybele in high esteem.
Some regard the Roman Catholic mass as a form of theurgy, in which the being of Christ is called down into the Host, transsubstantiation of the Host, and hence assimilation by the communicant. By a broader interpretation of the term, the mass could be considered theurgy in the sense that it contributes to the divinization henosis of the participants.
In Greek Orthodox Christianity, many of the services, including even baptism may contain theurgy (as Vladimir Lossky refers to Christian theurgy) in a thaumaturgical way, unlike magic, and not considered such within the tradition.
Following a pattern very similar to (and some suggest derived from) the Neoplatonists, the Medieval Jewish mystical tradition of Kabbalah developed the concept that the Universe is regarded as a series of emanations from the Godhead, namely, the 10 sephirot. It is said that God created the world using the sephirot, pouring Divinity into creation through these "vessels," which also have personality traits. The highest sephirah, Keter, holds the most divine light and is the least accessible to humanity. The lowest sephirah, Malkhut, is still higher than matter itself, so the parallel with Neoplatonism is not complete, but Malkhut is considered that aspect of God that can be perceived in the material world. It is also known as the Shekhinah.
For the Kabbalist, God is both singular and divided, but not into separate "gods." The teaching avoids polytheism by insisting that the sephirot are not to be prayed to, but rather, to be meditated on and experienced as attributes of God's personality, and our own. They are envisioned as arranged in three columns, in a pattern called the Tree of Life. By meditating on the sephirot and praying for their unification, Kabbalists seek the theurgic goal of healing a shattered world.
For Kabbalists, the sephirot are as follows: Keter (Crown); Chochma (Wisdom); Binah (Understanding); Chesed (Lovingkindness); Gevurah (Strength); Tiferet (Beauty); Netzach (Endurance); Hod (Glory); Yesod (Foundation); and Malkhut (Kingdom or Sovereignty).
2. Secrets of the Magickal Grimoires By:Aaron Leitchpgs. 241 - 278 (chapter 8)