Born circa 410 in Constantinople; died 485 in Athens. Classical idealist philosopher; representative of the Athenian school of Neoplatonism.

The most important of Proclus’ known works include Elements of Theology (most recent edition, Oxford, 1965; Russian translation in A. F. Losev, History of Classical Aesthetics, vol. 3: High Classicism, 1974) and Platonic Theology (most recent edition, Frankfurt am Main, 1960). Also among the most important of his known works are commentaries on the Platonic dialogues Timaeus (vols. 1–3, Leipzig, 1903–06) and Parmenides (most recent edition, 1961).

Proclus is historically important for his universal, constructive dialectical analysis of the entire system of Neoplatonism. All aspects of his philosophy are dominated by the triadic method, which is reducible to the consistent assertion of three elements, the first of which may be described as self-absorption, cause, the absolutely unified One, the existing totality, the paternal principle, or potentiality. The second of the triadic elements is emergence from the self, emanation beyond the limits of the self, causation (activity connecting the self with reality distinct from the self), the transition of the unified One into its many appearances, the principle of disintegration, the maternal principle, or energy. The third triadic element is the return from the world of appearances to the self; the emanation of disintegrated plurality into the absolutely unified One, which is infinitely varied within itself; and the eidos, or eternal, all-inclusive (structural) essence. Using the triadic method, Proclus analyzed each member of Plotinus’ universal triad—Unity (the One), the Intelligence (nous), and the Soul. For example, Proclus distinguishes the absolutely unknowable concept of “the One” from that of a “unity” containing a certain degree of plurality but lacking any qualities. The concept of “unity” refers only to the energy of differentiation and disintegration, which precedes Intelligence (differentiation). Proclus was the first Neoplatonist to assign this concept of “unity” to an independent stage of an “emanation” of the One—the realm of numbers, or “superexisting unities.”

Proclus also differentiated three aspects of the concept of “the Intelligence.” The first aspect is the Intelligence as self-absorption, the “intelligible” Intelligence as “being” or object. The second aspect is Intelligence as emergence from the self, the thinking or “intellectual” Intelligence, or Intelligence as subject. The third aspect is Intelligence as the return into the self, as the identity of being and thought or object and subject, and as “life,” “eternity,” or “life in itself.”

In his dialectic of mythology Proclus established three triads of gods. Owing to the triadic division of its first two members, the third triad constituted a group of seven (a hebdomad), each aspect of which was also divided into seven elements. Thus, the third triad of gods consisted of 49 god-intelligences.

According to Proclus, the world of the Soul is also triadic. There are divine souls (the “reigning,” “absolute,” and “intracosmic” gods), demonic souls (angels, devils, and heroes), and human souls.

As the quintessence of Neoplatonism, Proclus’ system, with its method of thinking, had a comprehensive influence on the development of medieval philosophy, from the Areopagite’s works to Michael Psellus, I. Petritsi, and Nicholas of Cusa.