The history of the Academy after Philo is very obscure, but early in our era we meet with a popular literary Platonism of which the writings of Plutarch are the best example. This popu lar Platonism insists on the value of religion, in opposition to Epicureanism, and on the freedom of the will and the reality of human initiative, in opposition to the Stoic determinism; a further characteristic feature, wholly incompatible with the genuine doctrine of Plato, is the notion that matter is inherently evil and the source of moral evil.
Genuine Platonism was revived in the third century A.D. at Rome, and independently of the Academy, by Plotinus. His Neo Platonism (q.v.) represents a real effort to do justice to the whole thought of Plato, but there are two sides of it which inevi tably, in the changed conditions, fell into the background, the mathematical physics and the politics. The third century A.D. had no understanding for the first, and the Roman Empire under a succession of military chiefs no place for the second. The doctrine of Plotinus is Platonism seen through the personal tem perament of a saintly mystic, and with the Symposium and the teaching of the Republic about the "Form of Good" always in the foreground. Plotinus lived in an atmosphere too pure for sec tarian polemic, but in the hands of his successors, Neo-Platonism was developed in conscious opposition to Christianity. Porphyry, his disciple and biographer, was the most formidable of the anti Christian controversialists ; in the next century, "Platonists" were among the allies and counsellors of the Emperor Julian in his ill advised attempts to invent an Hellenic counterpart to Christian ity.
Early in the fifth century, Neo-Platonism flourished for a short time in Alexandria (which disgraced itself by the murder of Hy patia in 415) and captured the Athenian Academy itself, where its last great representative was the acute Proclus (A.D. The latest members of the School, under Justinian, occupied them selves chiefly with learned commentaries on Aristotle, of which, those of Simplicius are the most valuable. The doctrine of the school itself ends in Damascius with complete agnosticism. Influence on Christian of Plato are prob ably to be detected in the Alexandrian Wisdom of Solomon; the thought of the Alexandrian Jewish philosopher and theologian Philo, at the beginning of our era, is at least as much Platonic as Stoic. There are, perhaps, no certain marks of Platonic influence in the New Testament', but the earliest apologists (Justin, Athe 'We may perhaps detect it in John i. 18 if the true text is "the only begotten God (.toPayevis 0E6s) which is in the bosom of the Father." This may be an echo of the phrase used in the Timaeus (92d) about the visible world "A God apprehensible to sense one and only begotten" (yovo-yEvis 6v). But it is not safe to assert it.
nagoras) appealed to the witness of Plato against the puerilities and indecencies of mythology. In the third century Clement of Alexandria, and after him, Origen, made Platonism the metaphys ical foundation of what was intended to be a definitely Christian philosophy. The Church could not, in the end, conciliate Platonist eschatology with the dogmas of the resurrection of the flesh and the final judgment, but in a less extreme form the Platonizing tendency was continued in the next century by the Cappa docians, notably St. Gregory Nyssen, and passed from them to St. Ambrose of Milan. The main source of the Platonism which domi nated the philosophy of western Christian divines through the earlier Middle Ages, were, however, Augustine, the greatest thinker among the Western Fathers, who had been profoundly influenced by Plotinus, read in a Latin version, before his conversion to Christianity, and Boethius, whose wholly Platonist vindication of the ways of Providence in his Consolatio Philosophiae was the favourite "serious" book of the Middle Ages.
A further powerful influence was exerted by the writings of the so-called Dionysius the Areopagite, which laid down the main lines of mediaeval mystical theology and angelology. These works are, in fact, an imperfectly Christianized version of the speculations of Proclus, and cannot date before the very end of the fifth century A.D. at the earliest, but they enjoyed an immense authority based on their attribution to an immediate convert of St. Paul.
After their translation into Latin in the ninth century by Johannes Scotus Erigena, their vogue in the West was as great as in the East. Apart from this theological influence, Plato dom inated the thought of the earlier Renaissance which dates from the time of Charlemagne in another way. Since the West pos sessed the philosophical writings of Cicero, with the Neo-Pla tonic comment of Macrobius on the Somnium Scipionis, as well as the Latin translation of the first two-thirds of the Timaeus by Chalcidius, with his commentary on the text, and versions, also, at least of the Phaedo and Meno, whereas nothing was known of the works of Aristotle except Latin versions of some of the logical treatises, the Middle Age, between Charlemagne and the beginning of the 13th century, when the recovery of Aristotle's physics and metaphysics from Moors, Persians and Jews began, was much better informed about Plato than about Aristotle; in particular in the various "encyclopaedias" of this period, it is the Timaeus which forms the regular background.