Theurgy

The term Theurgy is used to describe the practice of a series of rituals, sometimes seen as magical in nature, performed with the intention of invoking the action of God (or some other personified supernatural being or power), particularly with the goal of re-uniting oneself with the Divine, achieving theosis, and perfecting oneself. The Catholic mass can in fact be considered a form of theurgistic ritual, in which the being of Christ is invoked into the Eucharist.

Theurgy literally means divine-working. The source of Western theurgy can be found in the philosophy of the Neoplatonists, especially one Iamblichus. The universe is regarded as a series of emanations proceeding from the Godhead. Matter itself being the lowest form or manifestation of these emanations, and therefore is not in essence considered to be different from the Divine. Although opinions concerning the number and qualities of these emanations vary, most were in agreement that God was singular and good. Neoplatonists were technically polytheists, they also embraced a form of monism: reality itself is multi-faceted, with varied gods, but they all represented aspects of the one reality, though in accordance with the perceptions and culture of the individual.
According to Plotinus, and Iamblichus' teachers Anatolius and Porphyry, the emanations are as follows:
The One: Deity without quality, sometimes called The Good. Mind: The Universal consciousness, from which proceeds the psyche
Soul: Including both individual and world soul, leading finally to
The Physical, or Nature as we perceive it.
Plotinus urged preparation and deep contemplations for those who wished to perform theurgy, the goal of which was to reunite with God. Therefore, his school resembled, and was structured as a school of meditation or deep thought. One of his students, Iamblichus of Syria, taught a more ritualized method of theurgy, that involved invocation and religious, as well as magical ritual. Iamblichus believed theurgy was an act of imitation of the gods themselves, and in his work entitled "On the Egyptian Mysteries," he described theurgic ritual and practice as "ritualized cosmogony" that endowed embodied souls with the divine responsibility of creating and preserving the cosmos, or allowing disembodied souls (the gods) to work through the practioner.
Iamblichus' analysis was that the spiritual cannot be fully understood by mental contemplation alone because the spiritual transcends reason and 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 magical acts; at the higher level, with mental and purely spiritual practices. Starting with a working knowledge of the relation of the aspects of the divine in the physical world, the theurgist eventually reaches the level where the soul's inner divinity re-unites with God from whence it originated, and achieves a sense of closeness and nurture for all creation, especially humanity.