Elements of Theology

Structure and Method

Proclus’s Elements of Theology (Stoicheiōsis Theologikē) is a concise, highly formal presentation of Neoplatonic metaphysics. Modeled self‑consciously on Euclid’s Elements, the work is organized into 211 propositions, each followed by a brief demonstration. Instead of deriving geometrical theorems, Proclus aims to deduce the structure of all reality from minimal, broadly Platonist assumptions.

The style is deliberately axiomatic and impersonal. Proclus rarely argues polemically; he sets out conceptual relations he regards as necessary, often relying on logical principles such as priority and posteriority, causal dependence, and the ascent from composite to simple. The work is not “theology” in a revealed or confessional sense, but a rational theology: the study of the first principle (the One) and all that follows from it.

The text proceeds top‑down, beginning with the most universal and simple principle—the One—and gradually unfolding a descending sequence: from the One to unities (henads), then to intellect (nous), soul (psychē), and finally the realm of embodied, temporal beings. In this way, it functions both as a metaphysical handbook and as a technical summary of late Athenian Neoplatonism.

Central Doctrines

Although highly compressed, the Elements of Theology articulates a comprehensive metaphysical system. Several clusters of propositions are especially central.

The One and Causality

The opening propositions define the One as that which is absolutely simple, beyond all multiplicity and determination. Every being that exists is in some way multiple (e.g., by having form and matter, or potency and act), so the cause of being must transcend being itself. Thus:

• All things participate the One as the source of their unity.
• The One is beyond being and beyond intellect, not an object of discursive knowledge but the ultimate condition of knowability.
• Causation is understood in terms of procession (proodos) and reversion (epistrophē): every effect proceeds from its cause yet reverts toward it as its good.

From these principles Proclus derives a general theory of hierarchy: causes are more unified, simple, and universal; effects are more multiple and particular. No level of reality is isolated; each is linked vertically by dependence on superior causes.

Henads and the Divine Manifold

Proclus introduces the distinctive doctrine of henads—a plurality of “ones” that stand between the absolutely simple One and the realm of being. These are identified with the gods of traditional Platonism and pagan religion. Each henad:

• Is one by participation in the One,
• Is a unique source of a particular order of beings,
• Is beyond being but functionally a mediating principle.

This allows Proclus to reconcile radical unity at the summit of reality with a richly differentiated polytheistic theology. The Elements itself remains largely abstract, leaving mythic elaboration to other works, but it provides the metaphysical scaffolding for a hierarchical pantheon.

Intellect, Forms, and Soul

Below the level of henads lies intellect (nous), the first realm that properly has being. Intellect is characterized by:

• Self‑thinking thought: it knows itself by contemplating the intelligible Forms.
• Identity of knower and known: no gap divides subject and object.
• Containing within itself the totality of Forms, which serve as stable paradigms for all lower realities.

From intellect proceeds soul (psychē). Soul mediates between the unchanging intelligible realm and the changing, temporal world. Proclus distinguishes:

• Higher (universal) souls, such as the World Soul and cosmic orders of soul,
• Particular souls, including human souls, capable of discursive thinking and temporal life.

The Elements elaborates multiple levels and functions of soul, emphasizing that all souls:

• Originate from and depend on intellect,
• Possess an inherent tendency of reversion toward their causes,
• Are capable, in differing degrees, of participation in intelligible reality.

Participation, Procession, and Reversion

A key theoretical triad structures the entire work:

• Participation (methexis): lower beings share in higher principles without exhausting or dividing them.
• Procession (proodos): effects flow out from causes while remaining dependent on them.
• Reversion (epistrophē): every being naturally turns back toward its cause as its good and fulfillment.

These notions underpin Proclus’s treatment of unity and multiplicity, whole and part, universal and particular, and the gradations of being. The work thus aims to show that the cosmos is a coherent, ordered series of participatory relations, not a collection of independent entities.

Transmission and Influence

Though composed in 5th‑century Athens, the Elements of Theology exerted its greatest influence indirectly and outside the pagan philosophical schools.

A major vehicle was the Latin Liber de Causis (Book of Causes), an anonymous Arabic adaptation of parts of the Elements that circulated in medieval Europe as an Aristotelian work. Key Proclean ideas—such as the priority of the first cause, the structure of causality, and the notion of emanation—entered Latin scholasticism this way. Only in the 13th century did Thomas Aquinas and others, through William of Moerbeke’s translation of Proclus, recognize the Proclean origin of much in the Liber de Causis.

In the Christian Platonist tradition, Proclus influenced Pseudo‑Dionysius the Areopagite, whose hierarchical angelology and apophatic theology show structural parallels with the Elements. Through Dionysius, Proclean themes shaped Eastern Orthodox and Western medieval thought, including the work of Maximus the Confessor, Eriugena, and later mystical theologians.

In the Islamic world, Proclean doctrines entered philosophy mainly via the Liber de Causis and related Arabic texts, informing the metaphysics of al‑Fārābī, Avicenna, and others, especially in their accounts of emanation, separate intellects, and the hierarchy of being.

Early modern and modern philosophers rediscovered the Elements directly through Greek editions and translations. German idealists such as Hegel engaged with Proclus as a significant systematic Platonist, and contemporary scholars of Neoplatonism have treated the work as a crucial witness to late antique metaphysics. Modern interpreters debate the coherence and ontological commitments of Proclus’s system, yet widely agree that the Elements of Theology is one of the most rigorous attempts to present a fully deductive metaphysical theology in the Platonic tradition.