IAMBLICHUS, the chief representative of Syrian Neo-Platonism, is only imperfectly known to us in the events of his life and the details of his creed. We learn, however, from Suidas, and from his biographer Eunapius, that he was born at Chalcis in Ccele-Syria, the scion of a rich and illustrious family, that he studied under Anatolius and afterwards under Porphyry, the pupil of Plotinus, that he himself gathered together a large number of disciples of different nations with whom he lived on terms of genial friendship, that he wrote " various philosophical books," and that he died during the reign of Constantine,accord-ing to Fabricius, before 333 A.D. His residence (probably) at his native town of Chalcis was varied by a yearly visit with his pupils to the baths of Gadara. Of the books referred to by Suidas only a fraction has been preserved. His commentaries on Plato and Aristotle, and works on the Chaldsean theology and on the soul, are lost. For our knowledge of his system we are indebted partly to the fragments of these writings preserved by Stobseus and others, and to the notices of his successors, especially Proclus, partly to his five extant books, the sections of a great work on the Pythagorean philosophy. Besides these, Proclus (412-485) seems to have ascribed to him the authorship of the celebrated book On the Egyptian Mysteries (so-called), and although its differences in style and in some points of doctrine from the writings just mentioned make it improbable that the work was by Iamblichus himself, it certainly emanated from his school, and in its systematic attempt to give a speculative justification of the polytheistic cultus of the day, marks the turning-point in the history of thought at which Iamblichus stood.
As a speculative theory Neo-Platonism had received its highest development from Plotinus. The modifications introduced by Iamblichus were the elaboration in greater detail of its formal divisions, the more systematic application of the Pythagorean number-symbolism, and chiefly, under the influence of Oriental systems, the thorough-going mythic interpretation of what the previous philosophy had still regarded as notional. It is on the last account, probably, that Iamblichus was looked upon with such extravagant veneration. As a philosopher he had learning indeed, but little originality. But by using what he had to throw a haze of philosophy over the popular superstition, he acquired his fame. By his contemporaries he was accredited with miraculous powers (which he, however, disclaimed), and by his followers in the decline of Greek philosophy, and his admirers on its revival in the 15th and 16th centuries, his name was scarcely mentioned without the epithet " divine " or "most divine," while, not content with the more modest eulogy of Eunapius that he was inferior to Porphyry only in style, the emperor Julian regarded him as not even second to Plato, and said that he would give all the gold of Lydia for one epistle of Iamblichus.
Theoretically, the philosophy of Plotinus was an attempt to harmonize the principles of the various Greek schools. At the head of his system he placed the transcendent incommunicable one (ev apceOeKTov), whose first-begotten is intellect (vols), from which proceeds soul (I/O>Y»/), which in turn gives birth to <jjvxris, the realm of nature. Immediately after the absolute one, Iamblichus introduced a second superexistent unity to stand between it and the many as the producer of intellect, and made the three succeeding moments of the development (intellect, soul, and nature) undergo various modifications. He speaks of them as intellectual (Oeol vocpoi), supramundane (vTrepKorrp,loi), and mundane gods (eyKocr/Atoi). The first of these-which Plotinus represented under the three stages of (objective) being (oV), (subjective) life (t,u>if), and (realized) intellect (voSs)is distinguished by him into spheres of intelligible gods (Oeol vorjTot) and of intellectual gods (6eol voepol), each subdivided into triads, the latter sphere being the place of ideas, the former of the archetypes of these ideas. Between these two worlds, at once separating and uniting them, some scholars think there was inserted by Iamblichus, as afterwards by Proclus, a third sphere partaking of the nature of both (Oeol VOYJTOI KOX voepoi). But this supposition depends on a merely conjectural emendation of the text. We read, however, that " in the intellectual hebdomad he assigned the third rank among the fathers to the Demiurge." The Demiurge, Zeus, or world-creating potency, is thus identified with the perfected voCs, the intellectual triad being increased to a hebdomad, probably (as Zeller sup-poses) through the subdivision of its first two members. As in Plotinus voCs produced nature by mediation of uV^r/, so here the intelligible gods are followed by a triad of psychic gods. The first of these is incommunicable and supramundane, while the other two seem to be mundane though rational. In the third class, or mundane gods (8eol iyKocr/xloi), there is a still greater wealth of divinities, of various local position, function, and rank. We read of gods, angels, demons, and heroes, of twelve heavenly gods whose number is increased to thirty-six or three hundred and sixty, and of seventy-two other gods proceeding from them, of twenty-one chiefs (^-ye/wcs) and forty-two nature-gods (Oeol yeveo-Lovpyoi), besides guardian divinities, of particular individuals and nations. The world is thus peopled by a crowd of superhuman beings influencing natural events, possessing and communicating knowledge of the future, and not inaccessible to prayers and offerings.
The whole of this complex theory is ruled by a mathe-matical formulism of triad, hebdomad, ifec, while the first principle is identified with the monad, voBs with the dyad, and y>ux?7 with the triad, symbolic meanings being also assigned to the other numbers. " The theorems of mathe-matics," he says, "apply absolutely to all things," from things divine to original matter (i>Ai?). But though he thus subjects all things to number, he holds elsewhere that numbers are independent existences, and occupy a middle place between the limited and unlimited.
Another difficulty of the system is the account given of nature. It is said to be " bound by the indissoluble chains of necessity which men call fate," as distinguished from divine things which are not subject to fate. Yet, being itself the result of higher powers becoming corporeal, a continual stream of elevating influence flows from them to it, interfering with its necessary laws and turning to good ends the imperfect and evil. Of evil no satisfactory account is given : it is said to have been generated accidentally.
In his doctrine of man Iamblichus retains for the soul the middle place between intellect and nature it occupies in the universal order. He rejects the passionless and purely intellectual character ascribed to the human soul by Plotinus, distinguishing it sharply both from those above and those below it. He maintains that it moves between the higher and lower spheres, that it descends by a neces-sary law (not solely for trial or punishment) into the body, and, passing perhaps from one human body to another, returns again to the supersensible. This return is effected by the virtuous activities which the soul performs through its own power of free will, and by the assistance of the gods. These virtues were classified by Porphyry as political, purifying (KaOapTiKai), theoretical, and paradigmatic; and to these Iamblichus adds a fifth class of priestly virtues (lepaTiKcu antral), in which the divinest part of the soul raises itself above intellect to absolute being.
Iamblichus does not seem ever to have attained to that ecstatic communion with and absorption in deity which was the aim of earlier jSTeo-Platonism, and which Plotinus enjoyed four times in his life, Porphyry once. Indeed his tendency was not so much to raise man to God as to bring the gods down to mena tendency shown still more plainly in the " Answer of Abamon the master to Porphyry's letter to Anebo and solutions of the doubts therein expressed," afterwards entitled the Liber de Mysteriis, and ascribed to Iamblichus.
In answer to questions raised and doubts expressed by Porphyry, the writer of this treatise appeals to the innate idea all men have of the gods as testifying to the existence of divinities countless in number and various in rank (to the correct arrangement of which he, like Iamblichus, at-taches the greatest importance). He holds with the latter that above all principles of being and intelligence stands the absolute one from whom the first god and king spontaneously proceeds; while after these follow the etherial, empyrean, and heavenly gods, and the various orders of archangels, angels, demons, and heroes distinguished in nature, power, and activity, and in greater profusion than even the imagi-nation of Iamblichus had conceived. He says that all the gods are good (though he in another place admits the existence of evil demons who must be propitiated), and traces the source of evil to matter; rebuts the objection that their answering prayer implies passivity on the part of gods or demons ; defends divination, soothsaying, and theurgic practices as manifestations of the divine acti-vity ; describes the appearances of the different sorts of divinities; discusses the various kinds of sacrifice, which he says must be suitable to the different natures of the gods, material and immaterial, and to the double condition of the sacrificer as bound to the body or free from it (differing thus in his psychology from Iamblichus); and, in conclusion, states that the only way to happiness is through knowledge of and union with the gods, and that theurgic practices alone prepare the mind for this union again going beyond his master, who held assiduous con-templation of divine things to be sufficient. It is the passionless nature of the soul which permits it to be thus united to divine beings,knowledge of this mystic union and of the worship associated with it having been derived from the Egyptian priests, who learnt it from Hermes.
On one point only does the author of the De Mysteriis seem not to go so far as Iamblichus in thus making philo-sophy subservient to priestcraft. He condemns as folly and impiety the worship of images of the gods, though his master held that these " simulacra " were filled with divine power, whether made by the hand of man or (as he believed) fallen from heaven. But images could easily be dispensed with from the point of view of the writer, who not only held that all things were full of gods (-n-avTa TrX-qp-q Oewv, as Thales said), but thought that each man had a special divinity of his ownan lotos Satjucovas his guard and companion.
Bibliography.Of the five extant hooks of Iamhlichus referred to above, (1) that On the Pythagorean Life (ivepl rov TlvSayopmov iSioB) was first edited, in Greek and Latin, by Arcerius Theodoretus, 1598 ; again by Kuster, 1707; and by Kiessling, Leipsic, 1815-16 ; while a new edition is promised by E. Rhode, who discusses the sources, &c, of the work in the PJiein. Museum, vol. xxvi., 1871, pp. 554sq.; cf. vol. xxxiv., 1879, pip. 260 sq. (2) The Exhortation to Philosophy (\oyoi irpoTpcTTTiKol eh <pi\oo-o<piav) was edited first along with the former in 1598, and again by Kiessling, Leipsic, 1813. (3) The treatise On the General Science of Mathematics (ir. rijs KOIVTIS y.a8-n par IKTIS) was edited by Villoison, Anecd. Grceca, ii. 188-225, Venice, 1781; and a useful account of the same is given by J. G. Friis in his lntroduetio in Librum Iamblichi Tertium, 1790. (4) The book On the Arithmetic of Nicomachus (ir. TTJS NIKO-y.axov hp id y.t]T iKTJs eleraywyys), along with fragments on fate (ir. flyapp-ervs) and prayer (TT. evxys), was edited in Greek and Latin by S. Tennulius, 1668 ; and (5) the Theological Principles of Arith-metic (StoXoyovy-eva rys apiBfi-nriK-Tis)the seventh book of the seriesby Ast, Leipsic, 1817. Two lost books, treating of the physical and ethical signification of numbers, stood fifth and sixth, while books on music, geometry, and astronomy followed.
The so-called Liber cle Mysteriis was rendered into Latin by Marsilius Ficinus, Venice, 1497, fol.,several times reprinted,and again by N. Scutellius, Rome, 1556, 4to. The original Greek was edited, with Latin translation and notes, first by T. Gale, Oxford, 1678, fob, and more recently by G. Parthey, Berlin, 1857, 8vo.
There is a monograph on Iambliehus by Hebenstreit (De Iam-
blichi, philosophi Syri, doctrina Christiana; rcligioni, quam imitari
studct, noxia, Leipsic, 1764), and one on the De Myst. by Harless (Das
Buch v. d. dgyp. Myst., Munich, 1858). The discussion by Meiners
on the genuineness of the De Myst. has been already referred to,
and seems to be conclusive against attributing it to Iambliehus.
Thomas Taylor, the English Platonist, translated the Life of Pytha-
goras and the Egyptian Mysteries (London, 1818 ; Chiswick, 1821).
The best accounts of Iambliehus are those of Zeller, Phil. d.
Grieehen, iii. 2, pp. 613 sq., 2d ed., and Vacherot, Hist, de VEcole
cl'Alexandrie, ii. 57 sq. (W. K,. SO.)
Besides the anonymous testimony prefixed to an ancient MS. of Proclus, De Myst. viii. 3 seems to he quoted __ the latter as Iambliehus's. Of. Meiners, " Judicium de Libro qui de Myst. JEg. inscrihitur," in Comment. Soc. Hey. Sci. Oott., vol. iv., 1781, p. 77.