surnamed "the Successor" (Διάδοχος), either from his being the successor of Syrianus in the direction of the Athenian school, or, which is much more probable, from his being regarded as the genuine successor of Plato, was the last and one of the most celebrated of the Neo-Platonists. He was born at Byzantium on the 8th of February, A.D. 412, though, as the son of the Lycian Patricius, he frequently regarded himself as a native of Xanthus, where the earlier part of his life was spent. From Xanthus he removed to Alexandria while still young, and was received into the family of Leonas the rhetorician, who introduced him to the leading scholars of the city. Purposing to pursue the study of jurisprudence, he studied grammar under Orion, and applied himself to the Latin tongue. Having visited Byzantium in the company of Leonas, he, immediately on his return, abandoned rhetoric and law for the study of philosophy, and sought the instructions of Olympiodorus. This choice of a teacher, while it could not have been called a happy one for an ordinary man, was eminently so for Proclus. The apparent obscurity of his master, his penetrating intellect rendered luminous; and what he could not fully understand on its delivery, he was enabled to preserve for future study by his prodigious memory. His master was charmed with his genius; so also was his master's daughter; whether or not for his talents, does not appear. Leaving Alexandria at the age of twenty, he chose Athens for a residence. He had the good fortune to make the acquaintance of Plutarchus, the son of Nestorius, who read with him the De Anima of Aristotle and the Phaedo of Plato. On his death, Plutarchus commended him to the care of Syrianus, who employed him as his coadjutor. So great was his industry and so intense his application, that by his twenty-eighth year he had written his commentary on the Timaeus of Plato. He succeeded Syrianus at his death, continued his school, and seems to have realized a handsome income from the undertaking. From whatever cause, he was compelled to quit Athens for a year, which afforded him leisure to visit the East, and compile a collection of Chaldean oracles. He opened school on his return; and seems to have disclosed the profounder principles of his philosophy only to his confidential disciples, on whom secrecy was enjoined. In his religious ceremonies he observed a like strictness. He was possessed of great strength and remarkable personal beauty, which numerous matrimonial Proconsul proposals still attest; but his adherence to fasts and vigils, to labour and asceticism, led him to decline such connections, and bestow his friendship upon Archiadas and others of his disciples. Of his theoric knowledge and discipline let nothing be said. The reader will find much of that and other absurd matters in the Vita Procli of Marinus. Proclus died on the 17th of April 485 A.D.

Twenty-two works or pieces of Proclus are still extant. There is no complete edition of them. That of Cousin (Paris, 6 vols. 8vo. 1820-27) contains the treatises on Providence and Fate, on the Ten Doubts about Providence, and on the Nature of Evil; the Commentary on the Alcibiades, and the Commentary on the Parmenides. The following have been translated into English by Thomas Taylor:—The Commentaries on the Timaeus, the six books on the Theology of Plato, the Commentaries on the first book of Euclid, the Theological Elements, the five Hymns, and his Life by Marinus. Besides the works already mentioned, seventeen others have unfortunately perished. Proclus regarded the Orphic and Chaldean oracles as divine revelations, capable of an allegorical interpretation, whereby he endeavoured to make Plato and Aristotle agree. He elevated faith (πίστις) above science; and strove to demonstrate that there is but one real principle of things—viz., Unity, which by its own development produces all things by triads. These triads he considered to be Unity, Duality, which is identical with limitation and boundlessness, and the complex of both, which contains Essence, Life, and Intelligence, the three fundamental dispositions of things. The Divinities he distinguished into Intelligible and Intelligent, Supernatural and Natural. He exalted Theurgy above Philosophy, attributed a supernatural efficacy to the name of the Supreme Being, and was hostile to the Christian religion.