Neoplatonism is the final period in the history of ancient Platonism. The beginning of Neoplatonic philosophy is the doctrine of Plotinus (204-269). Characteristic features of Neoplatonism are the doctrine of a hierarchically arranged world, the special attention to the theme of the "ascent" of the soul to its source, the development of practical ways of uniting with deity (theurgy) on the basis of pagan cults, in connection with this, a steady interest in mysticism, the Pythagorean symbolism of numbers. Antique Neoplatonism existed as a school philosophy and was focused on commenting on Plato's dialogues and systematically developing his teachings. Amelius and Porphyry belonged to the school of Plotinus in Rome.

Already at this early period, the basic concepts of the Neoplatonic system were developed: the One beyond being and beyond thought, it can be known in a supramental way out of the discourse (ecstasy); In the overabundance of one's power, the One generates by emanation, i.e. as if radiating, the rest of reality, representing a successive series of steps of the descent of the One. In Plotinus' model of reality, the One is the cause of the rest of reality, which takes the form of two subsequent "hypostases", Nous and Soul. The system of Plotinus was expounded in a series of treatises published after the death of Plotinus by Porphyry under the name of the Ennead. Fixed in the Enneads, the anti-Aristotelian position of Plotinus in the further development of Neoplatonism is replaced by the recognition of the role of Aristotle as a follower of Plato, Aristotle's philosophy, especially his logic, is understood as an introduction to the philosophy of Plato. Since Porphyry, Neoplatonism begins a systematic interpretation of the works of Plato and Aristotle.

One of the students of Porphyry was Iamblichus, the founder of the Syrian school of Neoplatonism. Iamblichus is known as the developer of the system for studying and commenting on Plato (the so-called canon of Iamblichus from the 12 Plato dialogues), as a fan of theurgy, the mystical practice of communicating with gods and spirits through ritual magic. The final stage of the study of philosophy under Iamblichus is the interpretation of Orphic texts and the Chaldean Oracles. The disciples of Iamblichus were his successor Sopater of Apamea, Dexippus, Theodorus of Asine and others.

One of the disciples of Iamblichus was Aedesius. He founded the Pergamon School of Neoplatonism, which continued the traditions of the Syrian one. Its representatives were Chrysanthius, Sallustius, author of the work On the Gods and the World, Eunapius, author of the valuable description of the philosophy of the Pergamon school called Lives of Philosophers and Sophists, Julian the Apostate (Roman emperor), during whose rule the characteristic confrontation between Christianity and paganism in the intellectual life of the empire was fully reflected.

The two main schools of late Neoplatonism were the Athenian and the Alexandrian. The Athenian school was founded by Plutarch of Athens as a continuation of the Platonic Academy, its most prominent figures were Syrianus, Proclus, the last head of the Academy of Damascius. At the Athenian school, the systematic description of the non-material levels of the world (classification of gods, spirits, ideal essences), conducted by Iamblichus, continued to be developed, while resorting to detailed and refined logical constructions. From 437, the Academy was headed by Proclus, who summed up the development of Platonism within the pagan polytheism, made numerous comments on Plato's dialogues and wrote a number of fundamental works, some of which were preserved. The next neoplatonic school was the Alexandrian school, including Hierocles, Hermias, Ammonius, Olympiodorus, Simplicius, John Philoponus. This school is primarily known for its commentary activity, and the main focus of its attention was on the writings of Aristotle. The Alexandrians showed great interest in mathematics and natural science, many of them turned to Christianity (Philoponus).

Neoplatonism had a great influence on the development of medieval philosophy and theology. The conceptual apparatus developed in school, the doctrine of aspiration for the imperishable and eternal, were rethought and entered into the context of Christian theology, both in the East (Cappadocians) and in the West (Augustine).