Proclus on magical signs

"Two passages of Proclus complementary to each other deal with a second group of magical signs. According to this author, the Chaldaeans believed that the "sign" (χαραχτήρ) "set in the heart" of the human soul consisted of a combination of semicircles and of the character X, and that the gods themselves had communicated the psychic signs of several Greek heroes and of Plato as well as their 'mystic names' which bring about their apparition.....While the apparition of Hecate was represented as that of a speaking flame, the philosopher's soul. became visible as a geometrical luminous figure. The belief that the apparition of the soul consists of semi-circles and of the charact derives from Plato's Timaeus, upon which Chaldeean metaphysics are based. For according to this work the Cosmic Soul consists of 2 axes having the shape of the letter X which are bent so as to form semicircles and joined together. We may accordingly surmise that the individual souls, regarded as the offshoots of the Cosmic Soul, were represented by the Chaldeans as being, as it were, her miniature copies. This transmutation of Platonic doctrines into magical diagrams is in entire conformity with the "hermeneutic method" used by the author of the Chaldean Oracles. " - H. Lewy, Chaldean Oracles and Theurgy, 254