Proclus

Proclus
	Proclus Lycaeus, late antique Neoplatonist philosopher
Tradition	Greek philosophy, Neoplatonism
Influenced by	Plato, Aristotle, Plotinus, Iamblichus, Porphyry of Tyre
Lifespan	412–485 CE
Notable ideas	Systematization of Neoplatonic metaphysics; hierarchy of being and procession–return; commentaries on Plato and Aristotle; integration of theology and philosophy
Occupation	Philosopher, Commentator, Mystic
Influenced	Pseudo-Dionysius the Areopagite, Boethius, Medieval philosophy, Renaissance Neoplatonism
Wikidata	Q271809

Proclus of Athens (c. 412–485 CE) was an influential Greek philosopher of late antiquity, best known as one of the last great Neoplatonists. As head of Plato’s Academy in Athens for about fifty years, he organized and refined the complex doctrines of Neoplatonism and ensured their transmission to later generations. Proclus wrote prolifically – covering subjects from mathematics and natural science to metaphysics and theology – and his works aimed to show how the ancient Hellenic religious tradition and Greek mythology were compatible with philosophical wisdom. He is especially noted for his commentaries on Plato’s dialogues and other texts and for articulating a grand metaphysical vision of cosmic procession and return. In Proclus’s account, all reality flows out from a single supreme principle and eventually returns to it in a unified ascent of souls and intellects.

This article explores Proclus’s life, his main writings, and the structure of his thought, including the central idea that the cosmos proceeds from and ultimately returns to the One. It also surveys his influence on philosophy after antiquity, the debates and criticisms around his work, and his legacy. The account is based on modern scholarship and aims to present a clear, balanced overview for readers interested in Proclus’s role as a Neoplatonic systematizer and metaphysician.

Early Life and Education

Proclus was born around 412 CE into a wealthy family from Lycia (a region in southwestern Asia Minor). His birth likely took place in Constantinople (modern Istanbul), but soon after he was raised in his parents’ native city of Xanthos. He initially studied rhetoric, following a family tradition of training for the law. A turning point came during a journey to Byzantium, where he discovered a passion for philosophy. Back in Alexandria, he immersed himself in philosophical studies, quickly mastering Aristotle’s works and Greek mathematics.

At about eighteen (around 430–431 CE) Proclus journeyed to Athens to study at the renowned Platonic Academy. He first studied Platonic and Aristotelian texts under Plutarch of Athens (not the biographer Plutarch of Chaeronea but a later Plutarch and head of the Athenian school). Plutarch introduced him to Plato’s Phaedo and Aristotle’s De Anima. When Plutarch died in 432, Syrianus succeeded him as head of the Academy. Proclus continued under Syrianus for the next six years, following a traditional curriculum that combined Aristotle’s works with the “greater mysteries” of Plato.

Under Syrianus’s guidance, Proclus not only studied the mainstream doctrines of Plato and Aristotle but also became acquainted with older mystical traditions. Syrianus taught the harmonies among Orphic, Pythagorean, Platonic, and Chaldean theogonies (ancient creation stories). Proclus absorbed these teachings, which treated Greek theology, Orphic hymns, and Chaldean Oracles as profound sources of wisdom to be integrated with philosophy. His respect for Syrianus was deep: Proclus never once criticized his teacher and often praised him in his own writings. (Indeed, on many matters it is difficult to distinguish Proclus’s original views from those he learned from Syrianus.)

After Syrianus died in 437 CE, Proclus became head of Plato’s Academy (holding the title diadochos, “successor”). He was then in his mid-twenties. For nearly the next half-century, until his death in 485 CE, he directed the school at Athens. Proclus lived in strict discipline: his day began with a Pythagorean-style prayer to the sun at dawn (with repeated prayers at noon and sunset) and included lectures on philosophy, supervised seminars with students reading Platonic dialogues, and time devoted to writing. He was married and known to be pious and temperate. According to his biographer Marinus, Proclus avoided any improper gain from his noted wealth, devoting himself instead to philosophy. Though he enjoyed the respect of many contemporaries (even some Christian students attended his school), the increasingly Christian political culture forced caution. About 444 CE, he felt compelled to leave Athens and spent roughly a year in voluntary exile in Lydia (central Asia Minor) to avoid conflict with authorities. He returned to Athens and taught there until his passing in 485.

Major Works and Writings

Proclus was famously prolific. According to his biographer Marinus, he reportedly wrote about 700 lines per day (roughly 20–25 pages) and had an “unbounded love of work.” If true, he left behind several hundred treatises. Today about one-third of that output survives; the rest is lost or known only through scattered fragments. His surviving corpus reveals the breadth of his interests:

Commentaries on Plato. At the core of Proclus’s output were extensive commentaries on Plato’s dialogues. Five major Platonic commentaries survive (some incomplete): on Alcibiades, Cratylus, Republic, Timaeus, and Parmenides. Through these works Proclus sought to uncover the philosophical and theological teachings hidden in Plato’s texts. He approached Plato allegorically, seeing the dialogues as encoded expositions of Neoplatonic truths.

Commentary on Euclid. Proclus wrote a famous commentary on Book I of Euclid’s Elements. In it he connects Greek mathematics with Platonist ideas. For example, he viewed geometric principles as reflecting eternal forms in the divine intellect. His work on Euclid became a classic in the history of mathematics, illustrating how math fit into his overall metaphysical system.

Systematic “Elements” treatises. Proclus authored terse, axiom-like sequences of propositions in several domains:

- Elements of Theology (Stoicheia Theologia): Perhaps his best-known work, this short text develops Neoplatonic metaphysics in 211 numbered propositions. Modeled after Euclid’s style, it presents a logical chain of metaphysical principles – about genera, causes, and hierarchies of being – that outline Proclus’s entire system. For later readers (in the Renaissance and even today) it is a concise introduction to his view of reality.

- Elements of Physics (Stoicheia Physica): This is a manual on nature, summarizing Aristotelian physics but reinterpreting it in Neoplatonic terms. Proclus treats physical processes as unified with higher intelligible causes, essentially making science a branch of theology (the study of divine causes).

- Elements of Arithmetic (Stoicheia Arithmetica): He also wrote a short treatise on numbers, harmonizing the Pythagorean significance of numbers with Platonic forms.

Astronomy and Mathematics. Hypotyposes Astronomicarum Positionum (Astronomical Hypotheses) is a treatise on astronomy. Proclus offered a geometric model of the motions of the planets and stars that incorporated Platonic ideas (for instance, bodies move in what he saw as circles or spheres reflecting intelligible forms). This survived through late antiquity and the Middle Ages. He also lectured on arithmetic, and fragments of a work on plane measures are known.

Ethics and Theology. Proclus wrote three connected “monographs” (sometimes called the Tria Opuscula) dealing with ethical and theological puzzles:

- On Providence (Ten Problems): discusses fate, determinism, and divine providence.

- On Fate (Liberty of Fate and Evil): examines freedom and determinism.

- On the Existence of Evils: explores why evil exists in a universe governed by the good.

Collectively, these works wrestle with how free will can exist under divine foreknowledge and how a benevolent cosmic order accommodates apparent evils.

The Platonic Theology. Perhaps his magnum opus, The Platonic Theology (Theologia Platonica), is an extensive systematic treatise (in 10 books) analyzing Plato’s ideas about the gods. It takes the statements about the divine in Plato’s works as its starting point and develops a full rational theology of the Neoplatonic gods and their attributes. In it, Proclus attempts a “scientific theology”: he classifies the gods (and principles) into hierarchies and derives their features logically. Only part of this work survives, but it was highly regarded in antiquity and beyond as the fullest exposition of pagan theology.

Hymns and Orphic/Chaldean writings. Proclus composed many hymns (in dactylic hexameter) praising various gods and cosmic principles. These Theological Hymns conceived the gods as cosmic forces (Time, Fate, the World-soul, and specific deities like Zeus, Athena, etc.) and were intended as poetic accompaniments to contemplation or ritual. He also wrote on Orphic and Chaldean religious texts (for example, a commentary on the Chaldean Oracles, a mystical set of revelations). Most of these works are lost or fragmentary, but they indicate his project of aligning mythology with philosophy. He saw Orphic and Chaldean lore as “revelation” containing truths about the One and its emanations.

Lost works and commentaries. Many of Proclus’s treatises are lost. He did write commentaries on parts of Aristotle’s Organon, on logic, and on some Socratic dialogues (e.g. Horoi or Definitions, a collection of Platonic terms), among others. Later Neoplatonists like Damascius preserved fragments or notes of these lost works, but those survive only in excerpts.

Overall, Proclus spanned the entire curriculum of late antiquity philosophy. He wrote on metaphysics, theology, physics, astronomy, mathematics, ethics, and exegesis of sacred traditions. One medieval biographer claimed he missed no class of knowledge. His style in these works varies: some are terse and formal (like Elements of Theology), while others are discursive and elaborate (his Platonic dialogues commentaries, for example). In all, Proclus aimed for a rigorous, almost encyclopedic presentation of Platonic thought, with rational proofs and a systematic method.

Proclus’s Philosophical System and Method

Proclus is often called the most systematic Platonist of late antiquity. He inherited centuries of Platonic and Neoplatonic thought – from Plato himself, through Plotinus and Porphyry, up to Iamblichus – and wove them into a highly ordered framework. His method was scholarly and deductive: he liked to arrange ideas in lists, sequences, or logical arguments, much as Euclid did in geometry. He introduced precise technical vocabulary (many terms were carried over from Syrianus and Iamblichus) and rigorously defined each level of reality and causation.

The One and the Triadic Structure

At the foundation of Proclus’s system is the One (sometimes called the Good or the First Principle). The One is beyond all being and thought; it is absolutely simple and unified. Proclus repeatedly stresses that the One has no attributes or parts and cannot even be said to exist in the same way things exist. It is pure unity and source. Yet the One somehow “gives birth” to multiplicity. Understanding how is key to Proclus’s system.

Proclus uses a triadic schema to explain causation. He follows his predecessors in saying that whenever a cause brings forth an effect, three aspects are always present: the monē (standing in itself, or unity), the prohodos (procession, or emanation), and the epistrophē (return). In Greek: monê-prohodos-epistrophê. This “triad of triads” appears everywhere in reality. Informally put:

Unity (monē): The cause and the effect share oneness, since the effect participates in the cause’s principle. This preserves the identity between them.

Procession (prohodos): The effect proceeds or comes forth from the cause. The cause “gives” being to the effect so that the many appear.

Return (epistrophē): The effect is drawn back to the cause. It has an innate urge or tendency to reunite with its source.

Each of these aspects is necessary. Proclus argues that if an effect did not proceed from its cause, there would be no way for it to share in the cause. If an effect did not return to its cause, it would remain completely disconnected and without purpose. And if cause and effect were not one, then no effect could truly come from its cause. Thus procession and return go hand in hand. Nothing in Proclus’s universe is static; every being depends on higher beings and also aspires to higher completion.

In practical terms, Proclus applies this triad to every level of reality. For example, when the World-Soul comes forth from the Intellect, it both emanates (procession) from the Intellect and simultaneously trends upward (return) toward the Intellect. The same pattern holds for any link between levels: intelligences issuing from the One, souls issuing from Intellect, and so on. This principle helps Proclus explain how the absolutely simple One can be the cause of a complex cosmos.

Emanation and Return

Building on the triad, Proclus describes a hierarchy or chain of being. Neoplatonists before him – especially Iamblichus – had taught a series of hypostases (fundamental realities): at the top the One, below that Intellect (Nous), then Soul (Psyche), then individual souls, and finally the material world. Proclus accepts this structure but adds richness and nuance to it. He often describes reality in terms of triads (One, Intellect, Soul) repeated at various levels. Sometimes he even speaks of multiple “sub-Trinities,” nested with the One at top.

One innovation in Proclus’s metaphysics is his doctrine of henads (Greek henades, meaning “units” or “unities”). These are intermediary unities between the One and the rest of reality. While the One itself is completely transcendent, the henads serve as “participated unities.” They bridge the gap between absolute oneness and the manifold world. In practical terms, each henad is associated with a principal god or divine principle (such as Zeus, Athena, Apollo, etc.), conceived as a unity radiating from the One. A henad is thus like a sun at the center of a smaller system, emitting rays to lower beings and receiving returns of those rays. This concept of henads allowed Proclus to integrate traditional Greek gods into his system: each god became a henad, a focal point of unity in the cosmos. Scholars debate whether Proclus invented this or received it from Syrianus or Iamblichus, but in any case Proclus systematized the idea.

Below the henads are levels of gods, daimons (spirits), and ultimately human souls and bodies. In Proclus’s scheme, the World-Soul (the soul of the cosmos) emerges from the Intellect and in turn nourishes individual souls. Each human soul is a self-moving principle: immortal and divine in origin, but attached to a body. Matter is at the bottom; it has no intelligible content except that it is the place where souls dwell temporarily and where multiplicity becomes concrete.

Throughout this chain, the flow of existence is always downward from the One to the many (prohodos) and upward from the many to the One (epistrophe). An individual soul, for example, proceeds from the higher realm of Intellect but is encased in a body in the physical world; its journey of return is to be “recollected” back upwards. In Proclus’s thought, even processes like creation, birth, and life are days of procession, while contemplation, virtue, and prayer are acts of return.

The One itself never changes and never “moves”; it is completely beyond all turning. Instead, motion and change occur in the derivative levels. This maintains the ultimate transcendence of the first principle. But every other being – every aspect of reality – participates in these emanation-return cycles. For Proclus, the cosmos is essentially a living, rational unity because of these interconnections. Each thing is simultaneously given by its cause and given back (in a higher mode of being).

Causality and “Unity Above”

Proclus follows the Neoplatonic principle that ”every cause is superior to its effect.” In other words, what causes something is always of a higher order. He further distinguishes between “proper” causes and “auxiliary” causes. A proper cause is completely outside and above the thing produced, while an auxiliary cause works within it. For example, an artist is a proper cause of a sculpture (the artist exists apart from the statue), whereas the artist’s tools are auxiliary causes (existing as parts within the sculpting process). This fits with his triad: the One is always far above its creatures (monē), then in procession it brings them into being, and ultimately they return to it. As Proclus puts it (in effect): an effect that did not proceed from its cause would be indistinguishable from the cause, and an effect that did not return to its cause would lack fidelity to it. All three (monē, procession, return) must hold.

This way of thinking yields some famous formulations. For instance, Proclus teaches that the soul ”lives between Eternity and Time.” By this he means that the soul has an immortal aspect (linked to the eternal Intellect) and a mortal aspect (linked to temporal becoming). The soul partakes of both realms, reinforcing the idea that it both “has come from” the eternal and “lives in” the temporal. It must thus reconcile these planes. He also famously asserts that ”thoughts (or intelligibles) are more real than things”, emphasizing that ideas and forms in the intelligible realm are primary, while material objects are only secondary reflections.

Knowledge and Psychology

In line with Plato, Proclus held that true knowledge is innate and is recollected through philosophy. Since the soul comes from Intellect, it has pre-existing concepts (dim echoes of the Forms) in memory. Learning is the process by which the soul remembers these higher truths. When we encounter something in the world, the soul recognizes its archetype (the idea in Intellect). This is analogical to Plato’s image of knowledge as anamnesis (recollection). Thus Proclus sees mathematics and geometry as initial steps of knowledge, since mathematical forms are the most accessible “eternal things” to the soul in the body; they train the mind to ascend toward more abstract truths.

Proclus had a hierarchical psychology: in the human being, he identified various soul-states or “positions” (diatheseis). For example, when thinking of mathematical objects, the soul is in one power; when performing an ethical action, it is in another. But ultimately all these capacities come from the one universal World-Soul. Human souls are moreover divided: each rational soul is part of a “soul triad.” The highest part of the soul is united with a god (a henad), the middle part reasons in the individual, and the lower part tends the body and senses. The crisis of ethical life for Proclus is when lower passions clash with higher reason – a problem he addresses in his treatises on fate and evil.

He also approaches eternal attributes in interesting ways. For example, he considers whether divine foreknowledge conflicts with human freedom. In On Providence and related works, he distinguishes God’s knowledge of future events (which for God are present) from human free choice. He attributes events partly to fate (necessary patterns ordained in the cosmos) and partly to providence (purposeful guidance by the divine) and partly to human agent causality. Each operates at its level, and Proclus argues they are compatible (though sometimes in modern terms his reconciliation seems strained). The details are technical, but it exemplifies that Proclus applies his metaphysical principles even to moral questions.

Theurgy and Religion

Proclus’s philosophy was not a dry rationalism; he believed in actual spiritual practice. He fully embraced the Neoplatonic idea, drawn from Plato’s later dialogues, that philosophy ultimately aims at union with the gods (homoiosis theōi). For Proclus, the gods of Plato and of traditional Hellenic religion were real divine intelligences, and human beings can commune with them. This communion, he thought, could be aided by the theurgy or hieratic art: sacred rituals, prayers, invocations, and symbols that activate the soul’s powers. This contrasts with Plotinus’s friend Porphyry (who was skeptical of all ritual) and represents the Iamblichean turn toward ritual as a necessary complement to intellect.

Proclus practiced theurgy himself. He mentions reciting hymns at sunrise and using symbols from astrology or myth in rituals. But he also insists that such rites must be grounded in correct knowledge. In his view, a ritual connects material media (like incense or chants) to their higher gods through cosmic sympathy. In his Commentary on the Timaeus, for example, he says that all things make “formless petitions” to the gods, except the One itself. So prayer and sacrifice are natural communications of reality upward.

Importantly, Proclus did not see reason and revelation as opposing forces. He maintained that myth and philosophy ultimately express the same truths. When a Platonic myth says the soul descended from heaven, it is metaphorically the same truth that philosophy teaches: souls originate in divinity. His Platonic Theology systematically treated Homer, Hesiod, Orphic hymns, and the Oracles as valid teachings about cosmic structures, interpreting all as true revelations cloaked in poetic language. This inclusive attitude made Proclus a champion of pagan religion in a time when Christianity was ascendant. He labored to show that the ancient gods were intelligible principles, not mere superstitions.

Style and Exegetical Method

Proclus’s writing style is often highly formal and technical. He frequently structures arguments as numbered propositions and relies on deductive logic. For many modern readers, especially outside philosophy, his texts can seem dense and abstract. In his Platonic commentaries, he uses a double commentary method: first he identifies what Plato himself says about an issue (drawing on previous commentators), then he adds his own philosophical exposition on the underlying principles. He weaves together literal, allegorical, and philosophical interpretations of dialogues. For instance, in his Cratylus commentary he famously interprets Plato’s discussion of names as reflecting the structure of reality and the powers of language.

Although he seldom presents original arguments in the modern sense, Proclus aimed at coherence and unity. He often begins a work by laying out common notions (koinai ennoiai) – fundamental concepts agreed upon first principles. For example, at the start of The Platonic Theology he lists notions like causality, procession, return, equality, etc., as shared foundations for discussing the gods. One may say Proclus’s method is more synthetic than critical: he assumes the truth of his Platonic and Pythagorean heritage and seeks to knit it into a consistent whole.

Influence and Reception

Proclus’s immediate influence was in the continuation of Neoplatonic schools. His pupils included, most notably, Ammonius of Alexandria, who took leadership of the Platonic school in Alexandria for a time. Several generations of late antique Platonists – Damascius, Simplicius, and others – studied his works and preserved his ideas in commentaries and treatises. In Athens, Proclus’s Academy remained a center of pagan learning until the mid-sixth century. (After Proclus’s death and that of his student Damascius, the school was eventually closed by the Christian emperor Justinian in 529 CE. The remaining philosophers fled to Persia, marking the end of the last classical Academy.)

Beyond antiquity, Proclus’s doctrines had a wide afterlife:

Byzantine East. In the Byzantine Empire, Neoplatonism maintained a presence in education and religion. Later Greek Orthodox thinkers often encountered Platonic ideas through a complicated transmission, and Proclus’s own works were known mainly in fragmentary or pseudonymous form. His emphasis on allegorical reading of Scripture, for instance, echoes in some Christian theology, although his pagan metaphysics was largely incompatible with Christian doctrine.

Islamic World. Proclus was known in the Islamic Golden Age, though his philosophy was often mediated through translations and adaptations. His Elements of Theology (or a similar text) circulated in Arabic, sometimes under the title that translates to “The Cosmic Treatise” or “Kitab al-Kawn” (Book of the Universe). Many medieval Muslim philosophers such as al-Farabi and Avicenna engaged with Neoplatonic ideas that ultimately trace back to Proclus (often indirectly via Plotinus or pseudo-Aristotelian texts). In fact, the pseudo-Aristotelian work Liber de causis (The Book of Causes), widely read in medieval Europe and assumed to be Aristotle’s, is a Latin translation of Proclus’s Elements of Theology. Likewise, fourteen works of Proclus were reportedly translated into Arabic and Syriac by the 10th–12th centuries (though none survive in full today). In summary, Proclus influenced Islamic philosophy by providing a blueprint of Neoplatonic causation and metaphysics, which Islamic thinkers sometimes modified to align with monotheism.

Latin West and the Middle Ages. In medieval Europe, knowledge of Proclus was patchy. Through Arabian intermediaries, certain works reached Latin scholars. The Liber de causis (the Latinized Elements of Theology) was studied as if it were Aristotelian and influenced thinkers like Thomas Aquinas. Not until the 13th century did Proclus’s actual works appear in Latin: the Dominican scholar William of Moerbeke translated Elements of Theology (1268), completing the gap left by the misattributed De causis. Moerbeke also translated Proclus’s Tria Opuscula (the three monographs on providence and evil) and portions of his large Commentary on the Parmenides. These were not widely read by later Scholastics (who tended to focus on Aristotle), but they did circulate among some scholars.

Renaissance and Early Modern Period. Interest in Proclus revived strongly during the Renaissance. Italian humanists and Platonists such as Marsilio Ficino, Giorgio Gemisto Plethon, and Federico Tozzi translated and studied his works. Ficino in particular was deeply influenced. He translated Platonic Theology, the Elements of Theology, and even imitated Proclus’s style by writing his own Christian Platonic Theology. Renaissance magi and thinkers saw in Proclus a champion of the wisdom of the ancients, harmonious with astrology, the occult, and mysticism. His concept of a chain from God to the world dovetailed with Renaissance syncretism. Even later philosophers such as Leibniz and Kant encountered Proclus (often critically) in discussions of metaphysics.

Modern Scholarship. Since the 19th century, classical scholars and historians of philosophy have studied Proclus for both his philosophical content and his place in history. Modern editions and translations of many of his texts have appeared (notably E.R. Dodds’s edition of Elements of Theology, and critical volumes of the Platonic Theology and commentaries). Proclus is often discussed for his elaborate metaphysics, his position in the Platonic tradition, and his influence on medieval and Renaissance thought. Today he is generally appreciated as a master compiler and expounder of Neoplatonic philosophy, if not an “original” thinker in the way that Plato or Plotinus were.

Throughout these stages of reception, two themes of Proclus’s legacy stand out. First, he was seen as a bridge between the classical pagan world and later cultures (Christian and Islamic) through the survival of his philosophical schema. Second, thinkers have admired or contested his vision of a cosmic hierarchy held together by divine causality. The idea that all reality emanates from unity and aspires back to it has had a long afterlife in various forms of metaphysics and mysticism.

Critiques and Debates

Proclus’s work attracted both admiration and criticism. In antiquity, his immediate teachers and successors praised him as the pinnacle of Platonic philosophy. Only after the Christianization of the empire did some start to view pagan Neoplatonists unfavorably, accusing them of heresy or superstition. Proclus’s open defense of paganism made him suspect to Christian critics. For example, a Christian theologian might reject his polytheistic framework out of hand. Proclus did believe in many gods (as stages of being), which is starkly at odds with monotheistic faiths. However, he attempted to frame those gods as aspects of one divine reality, and many Christian thinkers would later reinterpret such ideas allegorically.

Modern critics are more concerned with internal questions. Some scholars debate how “original” Proclus was versus merely an encyclopedist of earlier Neoplatonism. Did he truly innovate, or did he mostly repeat what Plotinus, Porphyry, and Iamblichus had taught? While Proclus certainly borrowed heavily (and revered Syrianus’s writings), he also introduced novel formulations (like the doctrine of henads and the rigorous triadic framework). Historians continue to discuss which ideas he took over and which he created.

Another debate centers on Proclus’s view of the Good and the One compared to Plato himself. Some interpret Proclus as extending Plato’s ideas faithfully; others see a departure. For instance, Plato sometimes speaks of the Good in unknowable terms, whereas Proclus identifies the One as God and makes it the pinnacle of his hierarchy. Some scholars argue that Proclus “Platonized” Aristotle’s metaphysics or vice versa, blending traditions in ways that Plato himself might not recognize. The question of how much Aristotle influenced Proclus (or how competently Proclus interpreted Aristotle) is also debated, given that Proclus had Aristotelian training but a Platonic agenda.

Proclus’s metaphysics has also been critiqued on philosophical grounds. His notion of processions and returns is sophisticated, but it raises the age-old question of emanation: how can the One, which is utterly simple, give rise to multiplicity at all? Proclus answers this by saying the One overflows its perfection, but critics (especially in the modern era) wonder if this is coherent. Similarly, the idea that souls have divine “seats” or that rituals actually effect union might strike a scientific or skeptical reader as mysticism. In short, someone could regard Proclus as offering a beautifully consistent myth-metaphor, but not an empirically verifiable theory.

However, Proclus’s defenders note that he was seeking a united vision of reality, not an experimental science. Within his own terms, he was extremely rigorous: he applied logical proofs to theology just as Euclid did to geometry. Many Neoplatonic and Renaissance readers praised the intellectual depth of his thought, even if later philosophies moved away from his assumptions.

In summary, criticisms of Proclus often come down to one’s stance on metaphysics itself. Those inclined toward materialism or rationalism may dismiss his system as fanciful; others find in it a richly symbolic vision of the universe. Proclus himself would have considered the ability to integrate all knowledge – philosophy, mathematics, theology, poetry – into a single coherent picture to be his greatest achievement.

Legacy

Proclus’s legacy is that of a towering figure at the crossroads of ancient and medieval thought. He is often called the last great pagan philosopher of classical antiquity. By systematizing Neoplatonism, he helped preserve and propagate Hellenic philosophical traditions well beyond their historical end.

His most enduring philosophical legacy may be the idea of emergence and return: the notion that the universe is an ordered, living procession from unity toward multiplicity and back again. This vision influenced later Neoplatonists and left marks on medieval theology and Renaissance Platonism. Even in modern philosophy, echoes of the “unity of knowledge” ideal or the hierarchical chain of being can trace a lineage to thinkers like Proclus (through schemes like the Great Chain of Being or the idea that reality is fundamentally structured).

Proclus also left a legacy in how one reads Plato. His allegorical and triple-reading approach to Plato (seeing dialogues as containing multiple levels of meaning: literal, moral, and metaphysical) became a model for medieval Christian and Islamic Platonists who read Greek philosophy as a hidden theology. His treatment of myth and theology paved the way for later syncretic scholars to see value in pre-Christian thought without abandoning reason.

In religious and esoteric traditions, Proclus has been regarded as the leading authority on theurgic practice. Some occult and New Age writers in more recent centuries have taken inspiration from his concept of divine correspondences and rituals to rise through spiritual realms.

In scholarly terms, Proclus is recognized as an essential source for the history of Neoplatonism. Modern historians study him to understand how Plato was interpreted in late antiquity and how ancient religion was defended intellectually. His surviving writings – especially the Elements of Theology and his commentaries – are still consulted by scholars of philosophy, classics, and medieval studies.

Today, the Academy of Athens (the successor institution of Plato’s school) sometimes cites Proclus as one of its last great directors. In Greek cultural memory, he is seen as a symbol of Hellenic philosophical heritage at its peak, standing firm even as the ancient world changed around him.

Selected Works

Elements of Theology (Stoicheia Theologia): A concise set of 211 propositions outlining Proclus’s metaphysical system. It covers causality, hierarchy of beings, and theological principles. (Translated by E.R. Dodds.)

Platonic Theology (Theologia Platonica): An extensive treatise (10 books in antiquity; much is lost) expounding on Plato’s doctrine of the gods and divine hierarchy.

Elements of Physics (Stoicheia Physica): A manual summarizing natural substances and causes, integrating Aristotelian physics into a Neoplatonic framework.

Astronomical Hypotheses (Hypotyposes Astronomicarum Positionum): Proclus’s cosmological model, explaining planetary motions with concentric spheres and uniform circular movement.

Tria Opuscula (“Three Monographs”): Treatises on Providence, Fate and Free Will, and the Existence of Evil. They discuss how divine foreknowledge, destiny, and human freedom coexist.

Commentary on the Timaeus: A detailed analysis of Plato’s Timaeus (cosmology), exploring creation and mathematics of the universe; largely preserved.

Commentary on the Parmenides: An extensive (but only partly surviving) work on Plato’s Parmenides, dealing with the nature of the One and Being.

Commentary on the Republic: An incomplete but significant interpretation of Plato’s Republic, linking its political and cosmological aspects.

Commentaries on Alcibiades and Cratylus: Expositions of these shorter dialogues, focusing on the soul’s self-knowledge and the philosophy of language respectively.

Commentary on Euclid’s Elements (Book I): A foundational text where he shows how geometry starts from first principles and connects to philosophical truths.

Theological Hymns: Poems in honor of gods (e.g. Hymns to the Good, to Rhea, to Hermes Pharmacus, etc.) that illustrate his religious and cosmic ideas in verse.

Other works: Many letters, definitions, and fragments, including On the Chaldean Oracles and Hindu references. (Shorthand references: Marinus, Life of Proclus, supplements by modern editors.)

Each of these works contributes to understanding Proclus’s aim: to treat the whole of reality – from numbers to stars to souls to gods – as parts of one divine Plan.

Conclusion

Proclus of Athens stands out as a consummate compiler and expounder of Neoplatonic philosophy. Through his numerous writings – most notably his Platonic commentaries and his Elements of Theology – he brought coherence and unity to a vast tradition of Platonic and mystical thought. His vision of the cosmos as an emanation from the One and a return of all beings to that One captures the essence of his metaphysics of procession and return. In championing the compatibility of Greek mythic religion and rational philosophy, Proclus was an energetic exponent of pagan philosophy in an age dominated by Christianity.

His influence reverberated through Byzantine, Islamic, and Western medieval philosophy, often under veils of pseudonymous authorship (as in the Liber de causis). In the Renaissance he was rediscovered as a fountainhead of Platonic wisdom. Today, Proclus is remembered as a philosophical systematizer who epitomized the grand scale of late antique Platonism. His work remains a key to understanding the Platonic-Neoplatonic worldview – one in which every part of the universe is bound by a divine order, tracing an eternal cycle from unity to multiplicity and back again.