Theurgy ( //; from Ancient Greek: θεουργία, theourgía) describes the practice of rituals, sometimes seen as magical in nature, performed with the intention of invoking the action or evoking the presence of one or more deities, especially with the goal of achieving henosis (uniting with the divine) and perfecting oneself. 
- Proclus (c. 480): theurgy is "a power higher than all human wisdom embracing the blessings of divination, the purifying powers of initiation and in a word all the operations of divine possession" 
- Keith Thomas: "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." 
- Pierre A. Riffard: "Theurgy is a type of magic. It consists of a set of magical practices performed to evoke beneficent spirits in order to see them or know them or in order to influence them, for instance by forcing them to animate a statue, to inhabit a human being (such as a medium), or to disclose mysteries." 
Theurgy means "divine-working". The first recorded use of the term is found in the mid-second-century neoplatonist work the Chaldean Oracles (Fragment 153 des Places (Paris, 1971): 'For the theourgoí do not fall under the fate-governed herd').  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.
- To Hen (τό ἕν), The One: Deity without quality, sometimes called The Good.
- Nous (Νοῦς), Mind: The Universal consciousness, from which proceeds
- Psychē (Ψυχή), Soul: Including both individual and world soul, leading finally to
- Physis (Φύσις), Nature.
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, a student of Porphyry (who himself was 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 Mysteries of the Egyptians, Chaldeans, and Assyrians, 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. The theurgist works 'like with like': at the material level, with physical symbols; 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 (332-363) embraced neoplatonic philosophy and worked to replace Christianity with a version of neoplatonic paganism. Because of his untimely death and the hold mainstream 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.
Esoteric Christianity accepts theurgy as a tradition that could greatly benefit a person. The main feat of Esoteric Christianity is to learn the mysteries of God (see Raziel) and to rise to higher consciousness in the understanding of God's relationship to individual consciousness. Theurgy, in the esoteric tradition, uses this knowledge to heighten one's own spiritual nature.  In Esoteric Christianity, theurgy usually is the practice of trying to gain the knowledge and conversation of one's higher self, or Inner God, to teach one spiritual truths and wisdom from God that one could not learn from man (see alchemy, Kabbalah, and Theosophy).[ citation needed] Some branches of Esoteric Christianity hold that if an Esoteric Christian, Rosicrucian or Theosophist practices it, he or she could potentially rise to the degree of Magus or Adept after a certain level of spiritual attainment. In a traditional and magical sense, theurgy is seen as the opposite of Goetia, even though many argue that they overlap.  Some organizations, such as the Hermetic Order of the Golden Dawn, claim to teach a type of theurgy that would help one ascend spiritually as well as understand the true nature of the self and its relation to the Divine and the Universe. The Golden Dawn has a somewhat significant historical following and influence;  while it is held that many theurgists are usually solitary practitioners and seek the divine light alone through ritual and inner spiritual and psychological equilibration. Theurgy in this hermetic sense stresses the need for the individual to separate and analyze the individual components that constitute everyday consciousness and reunite them in a way that changes one's personal awareness into a state that understands and partakes in spiritual grace. 
John Milbank, founder of Radical orthodoxy, asserts that theology "encourages a theurgy which aims at a liberation of nature from terror and distress and at a fully harmonious and beautiful interaction between humans and the natural world". He continues by stating that theology equally "encourages a theurgy which is a social work of maximising democratic participation and socialist sharing". 
Following a pattern very similar to the neoplatonists,[ citation needed] 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 sefirot. 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 sefirah, Keter "Crown", holds the most divine light and is the least accessible to humanity. The lowest sefirah, Malkuth, is still higher than matter itself, so the parallel with neoplatonism is not complete, but Malkuth 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 a single oneness, not 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 manifestations of how God acts in the world. 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 sefirot are as follows: Keter "Crown, Source"; Chokhmah "Wisdom"; Binah "Understanding"; Chesed "Loving-kindness"; Gevurah "Strength"; Tiferet "Beauty"; Netzach "Endurance"; Hod "Glory"; Yesod "Foundation"; and Malkuth "Kingdom, Sovereignty."
- Chaldean Oracles
- Deity Yoga
- Esoteric Christianity
- Julian (emperor)
- Magician (paranormal)
- Pseudo-Dionysius the Areopagite
- Edmonds III, Radcliffe G. 2019. "The Illuminations of Theurgy: Philosophy and Magic" pp. 314-377. Drawing Down the Moon: Magic in the Ancient Greco-Roman World. Princeton University Press.
- Proclus, On the theology of Plato, 1.26.63. E. R. Dodds, The Greeks and the Irrational, University of California Press, 1959).
- Keith Thomas, Religion and the Decline of Magic (1971), Penguin, 1973, 320-321.
- Pierre A. Riffard, Dictionnaire de l'ésotérisme, Paris: Payot, 1983, 340.
- Cf. "Lewy">Lewy, Hans, Chaldaean Oracles and Theurgy, Cairo 1956, pp. 421–466 (mostly consulted and quoted from the revised edition by Michel Tardieu, Revue des Études Augustiniennes 58 (1978)).
- SIORVANES, LUCAS (1998). Iamblichus. In E. Craig (Ed.), Routledge Encyclopedia of Philosophy. London: Routledge. Retrieved September 17, 2013, from http://www.rep.routledge.com/article/A062
- Cf. "Shaw">Shaw, Gregory, Theurgy and the Soul: The Neoplatonism of Iamblichus, Penn State Press, 1971, page 115.
- Louise Nelstrop, Kevin Magill, Bradley B. Onishi. Christian Mysticism: An Introduction to Contemporary Theoretical Approaches. Ashgate Publishing, Ltd., 2009, pp. 109–110.
- Aaron Leitch. Secrets of the Magickal Grimoires, chapter 8, pp. 241–278
- Chic and Tabatha Cicero, Self-Initiation into the Golden Dawn tradition, Chapter 1
- Israel Regardie, revised by Chic and Sandra Tabatha Cicero. The Tree of Life: an Illustrated Study in Magic.
- Milbank, John (2015). " WHAT IS RADICAL ORTHODOXY ? by John Milbank" (PDF). University of Freiburg. Retrieved 21 July 2020.