EVOCAZIONE. — From Lat. evocatio: a magical rite by means of which either a soul from the underworld or a deity from its abode is summoned. E. almost always has a divinatory purpose (necromancy), and is found both among the ancient civilized peoples and among contemporary primitive peoples.
In the classical Greco-Roman world, in addition to the account by Lucian, who identifies the Chaldean magi, masters of astrology, as highly skilled in this art, several evokers are known (it suffices to mention Tiresias and his daughter Manto, Medea, and Canidia), as well as celebrated cases of e., such as the one connected with Pompey at the battle of Pharsalus, in which a Thessalian witch, Eritone, summoned a dead man to foretell the outcome of the clash, and the e. of Juno Regina performed by Camillus during the battle of Veii (Livy, V, 21).
The evocatory rite essentially belongs to that particular form of magic which recognizes magical efficacy in certain gestures and words. Since through e. one can deprive an enemy of the assistance of his divinities, it is evident that an aura of mystery surrounds the magical formulas of evocation; these are therefore known only to personnel delegated to this type of practice, as was, in Rome, the college of the Pontiffs (cf. Macrobius, Sat., III, 9).