Neoplatonism

Compared with the other three traditions, Latin Christianity was slower in absorbing Neoplatonism, largely due to a paucity of sources, yet it became the most vibrant by the end of the Middle Ages. After Augustine, the principal Neoplatonic thinker was the Roman philosopher Boethius (c. 475–525), who brought Porphyry's Isagoge to a Latin audience and presented many Neoplatonic ideas in his own Consolation of Philosophy, which became a standard schoolbook. Two commentaries were also significant in the medieval schools: one on Plato's Timaeus by Calcidius (third or fourth century, considered by some a Middle Platonist rather than a Neoplatonist), another on the Dream of Scipio (an excerpt from Cicero's Republic) by the fifth-century Macrobius. The latter provided a concise summary of Plotinian metaphysics, which occasioned a controversy in the eleventh century, featured in Manegold of Lautenbach's Book against Wolfhelm.

A cultural revival during the twelfth century led to renewed interest in old texts and an influx of new translations. After thinkers such as Peter Abelard, William of Conches, Thierry of Chartres, and Bernardus Silvestris fruitfully reexamined the Calcidian Timaeus, their successors discovered that the newly arriving translations of Aristotle's treatises had more to offer the scholastic enterprise of systematic theology than did the less direct dialogues of Plato, of which only the Meno and Phaedo were added to the Latin corpus. However, since Aristotle came to the West via the Arabs, he was initially read as a Neoplatonist. Thomas Aquinas (1225–1274) was instrumental in correcting this error when he identified Proclus as the source for the Pseudo-Aristotelian Book of Causes after reading a Latin version of the Elements of Theology translated in 1268.

Although Aquinas was principally Aristotelian in outlook, his teacher, Albertus Magnus (c. 1200–1280), was partial to Neoplatonism and inspired a Neoplatonic approach in three other Dominican friars: Dietrich of Freiberg (c. 1250–c. 1310), whose interest in the Neoplatonic metaphysics of light inspired him to study optics; Meister Eckhart (c. 1260–c. 1328), the controversial mystic; and Berthold of Moosburg (c. 1300–after 1361), who wrote an extensive commentary on Proclus's Elements. Nicholas of Cusa (1401–1464) later drew upon these thinkers, as well as the twelfth-century Platonists and earlier sources, in constructing his own Neoplatonic worldview outlined in Learned Ignorance (1440), a reaction against the Aristotelianism dominant in the universities. Petrarch (1304–1374) had already urged a return to Plato, and this tendency within Italian Renaissance humanism culminated in the work of the Florentine philosopher Marsilio Ficino (1433–1499), whose translations and studies of the complete Plato, Plotinus, and other Platonic authors were influential throughout Europe for centuries.