Major Neoplatonist philosopher of the 3rd century AD (234 – ca 305 AD), disciple and editor of Plotinus, well known for his deep involvement in anti-Christian polemics.


Porphyry was born in Tyre of Phoenicia (modern Lebanon), ca 234 AD. Being of Greek-Syrian origin, he bore initially the hellenised Semitic name ‘Malkos’ or ‘Malchos’ (scil. ‘King’), which he changed later to ‘Basileus’ or ‘Porphyrios’. During his studies at the school of the outstanding philologist and Platonic philosopher Longinus in Athens he was acquainted with the basic doctrines of Middle Platonism – which are clearly discernible in his thought even after his later, decisive discipleship with Plotinus – while acquiring at the same time a rare encyclopedic erudition and solid philological training.

Evidence of Christian sources presenting him as an apostate from the Christian faith in which he grew up as a child (Socrates, Eccl. Hist. ΙΙΙ, 23) or informing us that during his youth he knew Origen personally (Eusebius, Eccl. Hist. VI.19.5) remain impossible to verify.

What is certain, on the contrary, is that around the age of thirty (in 263) he went to Rome, where he joined the circle of Plotinus – indisputably the most important Platonist philosopher of that time. The five or six years he spent there (until 268) sufficed to mark him out as one of the most important disciples of Plotinus: Porphyry was appointed by Plotinus to criticize and refute the latter’s Gnostic listeners, and it is to him that the master entrusted the philological preparation and edition of his own writings, which would be published under the title Enneads some thirty years after Plotinus’ death (in 301).

A bout of depression, which manifested itself with suicidal thoughts, obliged Porphyry to abandon Rome, following Plotinus’ advice, and to establish himself in Sicily. Most probably the greatest part of his work was written there. Fairly late in his life he married Marcella, the widow of a friend of his and mother of seven children, to whom he addressed a letter of philosophical content, still extant. On the basis of similar indications of recipients and dedications present in some of Porphyry’s works, it is possible to reconstruct to some extent the circle of his friends and/or students, among whom the most important is certainly Iamblichus. The introductory and pedagogical character of many of his works is an indication that Porphyry probably entertained an informal philosophical circle. This does not mean, however, that he ever founded his own ‘school’ (in the formal, institutional sense of the word) or that he officially succeeded Plotinus in Rome.

Among his public activities it is worth noting his energetic involvement in the pagan-Christian debate by writing a monumental (15-volume!) treatise Against the Christians, and his willing response to ‘the affairs of the Greeks needing him’ (Letter to Marcella, 4) – probably by participating in some way in the preparation of the Great Persecution against the Christians, which took place under Diocletian in 303.


Porphyry’s literary production is both voluminous and multifarious. The titles of no less than sixty writings of his are attested, of which only ten are extant; for the rest we must content ourselves with fragments, sometimes only with titles. The works pertaining to philosophy can be divided in the following categories:

(1) Works of encyclopedic nature, with an emphasis on the sciences of the mathematical quadrivium: Commentary to Ptolemy’s Harmonics (music theory), Introduction to Ptolemy’s Tetrabiblos (astronomy).

(2) Introductory works: to Plotinus’ Enneads and to the philosophy exhibited in them (On the Life of Plotinus and the Order of his Books, Launching-Points to the Intelligible Realm [Ἀφορμαὶ πρὸς τὰ νοητά], known as the Sententiae [ad intelligibilia ducentes] ), to logic (Introduction, usually called the Isagoge), to the history of philosophy (Philosophical History, Life of Pythagoras).

(3) Ethical works and exhortations to the philosophical way of life: Letter to Marcella, On Abstinence from the Ensouled Beings (ἔμψυχα), On What Is in Our Power (Περὶ τοῦ ἐφ᾽ ἡμῖν).

(4) Philosophical commentaries on Platonic dialogues (the Timaeus, probably also the Parmenides ), but also – for the first time in the Platonic tradition – on Aristotelian treatises (On Aristotle’s ‘Categories’, [proceeding] by Questions and Answers).

(5) Works on psychology: To Gaurus on How Embryos Are Ensouled, On the Return of the Soul (the title is preserved in Latin: De regressu animae), On the Cave of the Nymphs in the Odyssey, Miscellaneous Questions.

(6) Works with a religious interest, in which Porphyry either stresses the profound theological and ‘theosophical’ meaning contained in the sacred traditions and myths of Hellenism (On the Philosophy [to be derived] from Oracles, On Statues, or rather On Cultic Images [Περὶ ἀγαλμάτων], On the Styx, On the Cave of the Nymphs in the Odyssey, a commentary on the Chaldean Oracles) or engages in polemics: against theurgy (Letter to Anebo) or Christianity (Against the Christians).

Basic philosophical tenets

Porphyry’s philosophy can be summarized in the following interconnected points: (1) it is basically faithful to Plotinus, maintaining the emphasis put by him on logos and nous; (2) it derives a great deal from Middle Platonism and Neopythagoreanism; (3) it is innervated by a few real questions to which it is hard to give an answer; hence Porphyry’s inability to find solutions to every issue he raises, or his hesitations; (4) it advocates a Platonism with universalizing ambitions, open to embrace elements deriving from various religious traditions, both Greek and Oriental, but remaining chary of, if not overtly hostile to, innovation (theurgy, Christianity).

The ontological levels. Porphyry accepts the chasm introduced by Plato between the sensible and the intelligible world, as well as the triadic metaphysical structure of reality inaugurated by Plotinus (amounting to the hierarchy of the three ontological hypostases: One – Intellect – Soul), together with its ascensional dynamics – the ascension being, moreover, the organizing principle of the Enneads, in which the reader is guided gradually from the natural world and the Soul to the Intellect and the One. Porphyry also adopts two innovative ideas of his master: the absolute transcendence of the One, and the thesis that, after its descent, the human soul does not lose its connection with the intelligible world.

Transitions. Starting from the above certitudes, Porphyry asks three questions concerning the precise way in which the transition is made from one ontological level to the next: (1) Given that the One is transcendent and is not counted (συναριθμεῖται) among the Intelligibles, what kind of relation does it have with them and with the self-created (αὐτοπάτορα) Intellect? – Answer: Perhaps the eternal element of the Intellect connects it (συνάπτει) with the One. (2) What is the status of the Intelligibles, and what is their relationship to the Intellect? – Answer: The Intelligibles should not be perceived as separated and situated ‘out of the Intellect’ (ἔξω τοῦ νοῦ). (3) How can the incorporeal soul be present in the body? Potentially (δυνάμει)? Actually (ἐνεργείᾳ)? Thanks to another type of mixture? – Answer: By a mixed union (ἀσύγχυτος ἕνωσις): as life the soul remains inalterable, but as a giver of life it comes in union with the body without losing its identity.

The problem of matter. Porphyry avoids Numenius’ dualism by approaching the problem of matter in Plotinian terms, i.e. within the framework of a strict monism: he considers it as the ultimate, indirect emanation of the One, and as no more than an accessory cause (συναίτιον) – not an active one.

Psychology. Porphyry assumed the existence of the ‘vehicle’ (ὄχημα) of the soul*, which he linked not only to imagination, divination, and dreams but also to the transmission of the effects of theurgic rituals on the soul. He also discussed (and probably rejected) the Numenian distinction between two souls, one rational and one irrational, as well as the view that human souls may enter animal bodies, too, during the reincarnation process. Finally, he tried to determine how and when the embryo is ensouled, and how its soul evolves from the vegetative through the animal to the rational state.

Soteriology and ethics. Porphyry accorded great importance to the purification of the mind and the soul in view of their liberation from the body. He considered that in order to achieve this goal one can helpfully study the mathematical sciences of the quadrivium, live ascetically according to the Pythagorean way of life, and practice vegetarianism – for which he advocated in his On Abstinence from the Ensouled Beings. He was convinced that salvation can be achieved not by means of theurgy, but only thanks to the power of the nous.

Historical significance

With his systematic and philologically impeccable edition of the Enneads Porphyry contributed vitally to the diffusion of Plotinian Platonism. Taking up again the thread of Ammonius Saccas, which was cut because of Plotinus’ anti-Aristotelianism, Porphyry reintroduced irrevocably Aristotle in the Neoplatonic curriculum, basing his choice on the principle of harmonious agreement (συμφωνία) of Aristotle with Plato. This tendency was consolidated with Iamblichus, and flourished further thanks to the late Neoplatonic commentators of the Aristotelian corpus. Although Porphyry adopted a critical stance towards theurgy, and remained puzzled by its rituals, his genuine interest in religion and theology paved the way for the more mature, profound and systematic theology of Iamblichus. It is no coincidence that Porphyry was the first to write a commentary on the Chaldaean Oracles (as well as other ‘theological oracles’), thus recognizing their philosophical and soteriological value.


Porphyry’s work was extremely influential in both the Latin West and the Greek East. Although Porphyry was a sworn enemy of Christianity, his thought, quite paradoxically, had an important influence on the metaphysics of Christian theologians writing in Latin, like Augustine and Marius Victorinus, perhaps also on the formulation of the christological doctrines of the Arian ‘heretics’. On the other hand, his sharp criticism of Christianity urged the Christians to develop a refined philosophical argumentation in order to strengthen and establish their dogmas. His Isagoge became the basic manual of logic in Byzantium, the Arabic world and the Latin West (in Boethius’ translation) for at least a millennium: the classification of everything according to genus, species, difference, property, and accident (γένος, εἶδος, διαφορά, ἴδιον, συμβεβηκός) proposed in it inspired the so-called ‘Porphyrian tree’ (arbor Porphyriana), namely a tree-like diagram of dichotomous divisions used as a device for illustrating the ‘scale of being’ or ‘scale of predicates’. Moreover, that very work laid the foundations of a centuries-long debate concerning the categories (universalia), which divided Mediaeval philosophers.

Author: Constantinos Macris
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