Heracleon was a Gnostic who flourished about AD 175, probably in the south of Italy. He is described by Clement of Alexandria (Strom. iv. 9) as the most esteemed (δοκιμώτατος) of the school of Valentinus; and, according to Origen (Comm. in S. Joann. t. ii. § 8, Opp. t. iv. p. 66), said to have been in personal contact (γνώριμος) with Valentinus himself. He is barely mentioned by Irenaeus (ii. 41) and by Tertullian (adv. Valent. 4). The common source of Philaster and Pseudo-Tertullian (i.e. probably the earlier treatise of Hippolytus) contained an article on Heracleon between those on Ptolemaeus and Secundus, and on Marcus and Colarbasus. In his system he appears to have regarded the divine nature as a vast abyss in whose Pleroma were Aeons of different orders and/or degrees, emanations from the source of being. Midway between the supreme God and the material world was the Demiourgos, who created the latter, and under whose jurisdiction the lower, animal soul of man proceeded after death, while his higher, celestial soul returned to the Pleroma whence at first it issued. He seems to have received the ordinary Christian scriptures; and Origen, who treats him as a notable exegete, has preserved fragments of a commentary by him on the fourth gospel, while Clement of Alexandria quotes from him what appears to be a passage from a commentary on Luke. These writings are remarkable for their intensely mystical and allegorical interpretations of the text. Life Neander and Cave have suggested Alexandria as the place where Heracleon taught; but Clement's language suggests some distance either of time or of place; for he would scarcely have thought it necessary to explain that Heracleon was the most in repute of the Valentinians if he were at the time the head of a rival school in the same city. Hippolytus makes Heracleon one of the Italian school of Valentinians; but the silence of all the authorities makes it unlikely that he taught at Rome. It seems, therefore, most likely that he taught in one of the cities of S. Italy; or Praedestinatus may be right in making Sicily the scene of his inventions about Heracleon. The date of Heracleon is of interest on account of his use of St. John's Gospel, which clearly had attained high authority when he wrote. The mere fact, however, that a book was held in equal honour by the Valentinians