Evocation is the act of calling upon or summoning aspirit,demon,god or other supernatural agent, in theWestern mystery tradition. Comparable practices exist in many religions and magical traditions and may employ the use of pharmakeia with and without uttered word formulas.
TheLatin wordevocatio was the "calling forth" or "summoning away" of a city'stutelary deity. The ritual was conducted in a military setting either as a threat during asiege or as a result of surrender, and aimed at diverting the god's favor from the opposing city to the Roman side, customarily with a promise of better-endowed cult or a more lavish temple. Evocatio was thus a kind of ritual dodge to mitigate looting of sacred objects or images from shrines that would otherwise be sacrilegious or impious.
The calling forth of spirits was a relatively common practice inNeoplatonism,theurgy and other esoteric systems of antiquity. In contemporary western esotericism, the magic of thegrimoires is frequently seen as the classical example of this idea. Manuals such as the Greater Key of Solomon the King, TheLesser Key of Solomon (or Lemegeton), the Sacred Magic of Abramelin the Mage and many others provided instructions that combined intense devotion to the divine with the summoning of a personal cadre of spiritual advisers andfamiliars.
The grimoires provided a variety of methods of evocation. The Spirits are, in many cases, commanded in thename of God - most commonly using cabalistic and Hellenic 'barbarous names' added together to form longlitanies. The magician usedwands, staves,incense and fire,daggers and complex diagrams drawn on parchment or upon the ground. In Enochian magic, spirits are evoked into acrystal ball or mirror, in which a human volunteer (a 'seer') is expected to be able to see the spirit and hear its voice, passing the words on to the evoker. Sometimes such a seer might be an actual medium, speaking as the spirit, not just for it. In other cases the spirit might be 'housed' in a symbolic image, or conjuring into a diagram from which it cannot escape without the magician's permission.
While many later, corrupt and commercialised grimoires include elements of 'diabolism' and one (The Grand Grimoire) even offers a method for making a pact with thedevil, in general the art of evocation of spirits is said to be done entirely under the power of the divine. The magician is thought to gain authority among the spirits only by purity, worship and personal devotion and study.
In more recent usage,evocation refers to the calling out of lesser spirits, sometimes conceived of as arising from the self. This sort of evocation is contrasted withinvocation, in which spiritual powers are called into the self from a divine source.