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Plotinus (c. 205–270)

(c. 205270)

Plotinus, usually considered the founder of Neoplatonism, was probably born in Lykopolis, Upper Egypt, and he may have been a Hellenized Egyptian rather than a Greek. He turned to the study of philosophy when he was twenty-eight. Disappointed by several teachers in Alexandria, he was directed by a friend to Ammonius Saccas, who made a profound impression on him. Of Ammonius's teachings we know extremely little, but a promising line of investigation has been opened up in a comparison of Plotinus's doctrines with those of Origen the Christian, also a student of Ammonius. Of other students of Ammonius, Origen the Pagan and Longinus deserve special mention.

Plotinus was Ammonius's pupil for eleven years. He left Ammonius to join the expeditionary army of Emperor Gordianus III that was to march against Persia, hoping to acquire firsthand knowledge of Persian and Indian wisdom, in which he had become interested through Ammonius. When Gordianus was slain in Persia in 244, probably at the instigation of his successor, Philip the Arabian, Plotinus had to flee from the army campwhich could mean that he was politically involved in some way. Plotinus reached Antioch in his flight and from there proceeded to Rome, where he arrived in the same year. In Rome he conducted a school of philosophy and after ten years started writing. At about this time he gained influence over, or the confidence of, the new emperor, Gallienus, and it is possible that his philosophy was meant to aid the emperor in some way in his attempted rejuvenation of paganism. In any case, Plotinus asked the emperor to grant him land in order to found some kind of community, the members of which would live according to the laws (or Laws ) of Plato.

Despite the emperor's favorable attitude, a cabal of courtiers brought the plan to nothing, indicating that they may have seen in it some political implications. However, because the contents of Plotinus's writings and some facts of his life seem to point to a complete absence of political interests, the problem of Plotinus's involvement in affairs of state is controversial. Nevertheless it is strangely coincidental that his literary activity began in the first year of Gallienus's rule. Moreover, when Plotinus died (probably from leprosy, about two years after the assassination of Gallienus), he was not in Rome but on the estate of one of his friends (of Arabic origin), and only one of his pupils, a physician, was present. These circumstances make it difficult to rule out the possibility that Plotinus had left Rome and that his pupils had all dispersed at the death of Gallienus (between March and August of 268) because he and they were afraid they would be affected by the anti-Gallienus reaction; this would again contradict a completely apolitical interpretation of Plotinus.

Plotinus's works, which were all written in the sixteen years after 253, have come down to us only in the edition by his pupil Porphyry. Porphyry arranged the works according to content into six sections called enneads because each contains nine treatises; he arbitrarily created some treatises by dissecting or combining the originals. Independent of this arrangement, he indicated when each treatise was written by assigning it to one of three periods in the life of Plotinus: before Porphyry became Plotinus's student, 253263; while Porphyry was his student, 263268; after Porphyry left him, 268270. Whether Porphyry numbered the treatises within each period in strictly chronological order is open to some doubt. The presentation of Plotinus given here follows the three periods of Porphyry with only a few forward or backward references. The standard citation to Plotinus's work designates the number of the ennead first, by Roman numeral; the treatise second, by Arabic numeral; and the place of the treatise in Porphyry's chronological enumeration third, in brackets. The chapter number and, where relevant, the line number are also given in addition to the standard citation.

Contrary to the frequent attempts to present Plotinus's philosophy as a consistent whole, this presentation will stress all tensions by which the philosophy is permeated and leave it an open question whether Plotinus succeeded in reconciling them.


To understand the philosophy of Plotinus, a knowledge of some of the doctrines of Plato, Aristotle, the Neo-Pythagoreans, and the Stoics is very important.

In his dialogues Plato divided all reality into the realm of ideas (intelligibles) and the realm of sensibles, treating intelligibles alone as that which truly is (ousia ), which implied that they are eternal and changeless (but see below). One of these ideas, the idea of the Good, he elevated above others, calling it beyond being (epekeina ousias ). Comparable to the sun, it is the source of being and cognizability of all existents. In a lecture (or a lecture course) he seems to have identified the Good with the One.

Plato discussed the concept of the One in his dialogue Parmenides, ostensibly without any conclusion. In one passage he asserts hypothetically that if the One existed, it would be ineffable and unknowable. Whether this assertion was supposed to reveal the self-contradictory and, therefore, unacceptable character of the One, or on the contrary to express Plato's positive assertion as to the character of the One, is controversial. In another dialogue, The Sophist, Plato seems to contradict his standard doctrine concerning the unchangeable character of the ideas by ascribing life, change, and knowledge to the realm of ideas.

As to the realm of the sensible, Plato in his Timaeus explains the origin of the cosmos in the form of a mythas the work of a divine artisan (demiurge) who uses an ideal cosmos as model and fashions it out of something Plato calls "receptacle" and describes as void of any qualities, after ideas have in some way "entered" this void and by so doing created rudiments of the four elements. In addition to the physical universe the demiurge also fashions a cosmic soul and the immortal part of individual souls. The cosmic soul and the individual souls consist of a mixture of the same ingredients, on which mixture the demiurge imposes a numerical and a geometrical structure.

The immaterial and substantial character of the individual souls (or at least part of them) guarantees their preexistence and postexistence (immortality). They are all subject to the law of reincarnation.

In the Second Letter (the authenticity of which was never doubted in antiquity, though today it finds virtually no defender), Plato, in a brief, and entirely obscure passage, seems to compress his whole philosophy into a formula reading: There are three realms, the first related to "the king," the second to the second, the third to the third. Plotinus was convinced that Plato is here describing the three realms of the One, Intelligence, and the Soul (whereas many Christian writers were convinced that Plato must have darkly anticipated the doctrine of the Trinity).

From Aristotle, Plotinus drew an important presentation of Plato's philosophy, ostensibly different from the one professed by Plato in his dialogues. According to Aristotle, Plato had assumed a realm of mathematicals mediating between ideas and sensibles (other sources identified this realm with that of the soul). Aristotle also attributed to Plato the view that two opposite principles, the One and the Indeterminate Dyad, are the supreme principles constitutive of everything, particularly of ideas and mathematicalsa doctrine Aristotle related to a similar, equally dualistic doctrine of the Pythagoreans. Aristotle represented Plato as having identified the Indeterminate Dyad with the receptacle and as having seen in it the principle of evil.

Plotinus also adopted Aristotle's doctrine of Intelligence (nous) as superior to the rest of the soul. Aristotle implied that it alone is immortal, the rest being merely the "form" of the body, hence incapable of separate existence. Aristotle designated the supreme deity as Intelligence contemplating (that is, intelligizing) itself; the cognitive activity of the Intelligence differed from sensation in that its objects (immaterial intelligibles) are identical with the acts by which Intelligence grasps them.

Plotinus was also aware of Academic and Neo-Pythagorean attempts to take over and modify the two-opposite-principles doctrine by elevating the One above the Indeterminate Dyad (sometimes above another One, coordinated with the Dyad), which thus changed Plato's dualism into monism culminating in a transcendent One. Plotinus also knew of the syntheses of Plato's and Aristotle's philosophy attempted by some Platonists, especially of the second century CE, most prominently Albinus and Apuleius. Another influence was the strictly materialistic and immanentistic Stoic doctrine of the omnipresence of the divine in the cosmos. Finally, two Neo-Pythagorean teachers are particularly relevant as sources for Plotinus: Moderatus, who seems to have taken his cue from Plato's Parmenides, distinguishing a first One above being from a second and a third; and Numenius, who distinguished the supreme god from the divine artisan, creator of the cosmos.

Plotinus's Philosophy First Period, 253263

Plotinus subdivided Plato's realm of intelligibles into three: the One, Intelligence, and the Soul (presupposed in IV 8 [6], Ch. 6; V 4 [7], Ch. 1; VI 9 [9], Chs. 1f.; V 1 [10], Ch. 10; V 2 [11]).

the one

Following what are at best hints in Plato, Plotinus developed a full-fledged theory of the One as the highest principle, or cause. Precisely because it is the principle of everything that isand is therefore omnipresentit is itself above being (absolutely transcendental: VI 9 [9], Ch. 4, ll. 24f., Ch. 7, ll. 28f.; V 4 [7], Ch. 1, ll. 48; V 2 [11], Ch. 1). Since it is above being, it is fully indetermined (qualityless), although it may be called the Good as the object of universal desire. Because it is one, it is entirely undifferentiated (without multiplicity: V 4 [7]; VI 9 [9], Ch. 3, ll. 3945). As every act of cognition, even of self-cognition, presupposes the duality of object and subject, Plotinus repeatedly and strongly states that the One is void of any cognition and is ignorant even of itself (VI 9 [9], Ch. 6, l. 42; III 9 [13], Chs. 7, 9). He tries to mitigate this statement in some places, hesitatingly attributing to the One some kind of self-awareness (V 4 [7], Ch. 2, l. 16) or quasi awareness of its "power" to engender being (V 1 [10], Ch. 7, l. 13). In other places he distinguishes the ordinary kind of ignorance from the ignorance of the One and says that there is nothing of which the One is cognizant but that there is also nothing of which it is ignorant (VI 9 [9], Ch. 6, ll. 4650).


The realm of the One is "followed" by that of Intelligence (intellect, spirit, mindall somewhat inadequate translations of the Greek word nous ). Here, for the first time, multiplicity appears. Roughly, this realm (hypostasis) corresponds to Plato's realm of ideas and, therefore, to that of true being. But whereas Plato's ideas are self-sufficient entities outside the Intelligence that contemplates them, Plotinus develops a doctrine of the later Platonists (perhaps originating with Antiochus of Ascalon) that interpreted ideas as thoughts of God and insists that intelligibles do not exist outside the Intelligence (V 9 [5], Chs. 7f.; III 9 [13], Ch. 1). The structure of the second hypostasis also differs from that of Plato's ideal realm in that Plotinus assumes the existence of ideas of individuals; the resulting difficulty that the infinity of individuals would demand an infinity of ideas Plotinus meets by assuming that the sensible world is, as the Stoa had it, subject to cyclical destruction and regeneration and that in each of these worlds the same indistinguishable individuals, for which one idea would suffice, would exist (V 7 [18], Ch. 1).

Another difference between Plato's and Plotinus's realm of ideas is that Plotinus assumed the existence of souls in this realm (IV 8 [6], Ch. 3). This doctrine creates a special problem. The ideal Socrates, unlike the soul of Socrates, must be composed of soul and body. It should follow that the soul of the empirical Socrates should be only a copy of that of the ideal Socrates, a consequence that, however, Plotinus rejects in places (V 9 [5], Ch. 13; VI 4 [22] Ch. 14) and approaches in others (III 9 [13], Ch. 3; V 2 [11], Ch. 1, l.19). Finally, Plotinus's realm of Intelligence contains even archetypal matter.

Despite all this multiplicity Intelligence remains one. In it everything is contained in everything without losing its identity, just as in mathematics every theorem contains all the others and, thus, the totality of mathematics (V 9 [5], Chs. 6, 9; IV 3 [27], Ch. 2).

Plotinus found it necessary to relate his doctrine of the One and Intelligence to the doctrine of the two opposite principles that figures in Aristotle's obscure presentation of Plato's philosophy in the Metaphysics (A6, 987a29ff.). In that difficult passage (the text of which may be faulty), Plato is said to have identified ideas with numbers. Plotinus also found it necessary to relate his philosophy to the doctrine identifying the soul with number, the best-known example of which was Xenocrates' definition of the soul as self-changing number. Thus, Plotinus calls the realm of Intelligence the realm of number and calls the soul number (V 1 [10], Ch. 5). But as he conceives number to be derived from the interaction of One with plurality and yet elevates the One above the realm of Intelligence (being), he seems to assign to his One a double role, a doctrine very close to the Neo-Pythagorean assumption of a double One, one superior and transcendental and another inferior, present in the realm of Intelligence, or number (V 1 [10], Ch. 5).


Below the hypostasis of Intelligence Plotinus locates that of the Soul. Some souls remain unembodied; others "descend" into bodies. These bodies are either celestial or terrestrial. Celestial bodies offer no resistance to the soul's dwelling in them and thus these souls do not suffer from their incarnation (IV 8 [6], Ch. 2); terrestrial bodies, however, do offer resistance, and governing them may involve the soul to such an extent that it becomes alienated from Intelligence, its true home, and thus "sinks." In addition to these souls of individual bodies, Plotinus also assumes the existence of a cosmic soul (IV 8 [6], Ch. 7; III 9 [13], Ch. 3; II 2 [14], Ch. 2; I 2 [19], Ch. 1); thus, the world at large is one living organism. Probably the realm of the Soul does not consist of these individual souls alone; rather, they are all only individualizations of something we could call Soul in general (compare IV 3 [27], Ch. 4). In any case, all souls form only one Soul, and this unity implies that all souls intercommunicate by extrasensory means (IV 9 [8]).

Plotinus sometimes proves, sometimes merely assumes, not only the incorporeality, substantiality, and immortality of all the individual souls of humans, animals, and even plants (IV 7 [2], Chs. 28iii, 14), but also proves or assumes reincarnation, in the course of which the same soul may pass from the body of a human into that of a beast or a plant (III 4 [15], Ch. 2). Plato's best-known proof of immortality is based on the absolute simplicity and, therefore, indissolubility of the human soul. But Plato also taught that the soul is tripartite, and perhaps in an effort to reconcile these two doctrines, Plotinus assumes that the simple and, therefore, immortal soul on its "way" to the body receives additional, lower parts as accretions. This seems to be similar to a doctrine usually associated with Gnosticisma downward journey of the soul, during which it passes the several planetary spheres, each of which adds something to it.


The explanation of the relation of the three hypostases to one another leads to one of the most characteristic doctrines of Plotinus, but it is a strangely ambiguous one. This relation is described as "emanation," or "effulguration," of Intelligence from the One and of Soul from Intelligencean emanation that, however, leaves the emanating entity undiminished (VI 9 [9], Ch. 9; V 1 [10], Chs. 3, 57; compare III 8 [30], Ch. 8, l. 11). The emanating entity thus remains outside of its product and yet is also present in it (VI 4 [7], Ch. 3; VI 9 [9], Ch. 7), a position sometimes described as dynamic pantheism to distinguish it from immanentist pantheism. This emanation Plotinus describes as entirely involuntary: What is full must overflow, what is mature must beget (V 4 [7], Ch. 1, ll. 2641; V 1 [10], Ch. 6, l. 37; V 2 [11], Ch. 1, l. 8; compare IV 3 [27], Ch. 13).

Seen in this way, there is no fault, no guilt involved in emanation, nor is any justification of why the One had to become multiple necessary. On the contrary, the process deserves praise; without it the One would have remained mere potentiality, and its hidden riches would not have appeared (IV 8 [6], Ch. 5f.). But sometimes, particularly when discussing the Soul's descent, Plotinus speaks of emanation in an entirely different manner. Even the emanation of Intelligence from the One, let alone that of Soul from Intelligence, he describes in such terms as apostasy and falling away. It is recklessness and the desire to belong to nobody but oneself that cause Intelligence to break away from the One (VI 9 [9], Ch. 5, l. 29). The Soul is motivated to break away from Intelligence by the desire to govern, which causes the Soul to become too immersed in bodies; by a craving for that which is worse; by a will to isolation (V 2 [11], Ch. 1; IV 8 [6], Ch. 4, I. 10; V 1 [10], Ch. 1). Matter emanates from Soul as the result of the Soul's wish to belong to itself (III 9 [13], Ch. 3). The "lowest" kind of Soul (the vegetative) is called the most foolhardy (V 2 [11], Ch. 2, l. 6). Thus, instead of an outflow, we should speak, rather, of a fallwith all its implications of will, guilt, necessity of punishment, and so on. These two interpretationswe shall call the former optimistic and the latter pessimisticare difficult to reconcile.

intelligence and soul

Let us now consider the constitution of the second and third hypostases in additional detail. On the whole, Plotinus teaches that the One is in no way engaged in producing Intelligence. But sometimes he speaks as if Intelligence were the result of some kind of self-reflection of the One: The One turns to itself; this turning is vision; and this vision is Intelligence (V 1 [10], 7, l. 6but the text is uncertain). Once more, we see that it is not easy for Plotinus to deprive the One of all self-awareness (consciousness). In any case, Intelligence is already multiple and, thus, less perfect than the One. However, the outflow from the One would not be sufficient to produce Intelligence. Rather, this flow must come to a stopcongeal, as it were. Incipient Intelligence must turn back to its source to contemplate it, and only by this act does Intelligence become fully constituted (V 2 [11], Ch. 1, l. 10). The emanation continues, and Soul emerges, again constituted by its turning toward the source, which is Intelligence (V 1 [10], Ch. 6, l. 47; V 2 [11], Ch. 1, l. 18; III 9 [13], Ch. 5). In Soul, multiplicity prevails over unity, and perfection has therefore decreased.

From Soul emanates matter, the totally indetermined (III 9 [13], Ch. 3; III 4 [15], Ch. 1). Because Plotinus tends to split the Soul into a higher, lower, and lowest kind, it is only the lowest that is the source of matter. Matter, when illuminated by the Soul, becomes the physical world, the model of which is in the realm of Intelligence (Soul thus corresponds to Plato's divine artisan, the demiurge). Thus, Plotinus's system would seem to be entirely monistic. But sometimes Plotinus speaks as if matter existed by and in itself, "waiting" to be ensouled (IV 8 [6], Ch. 6, ll. 1820; V 2 [11], Ch. 1).

Emanation must be described in temporal terms. But, of course, it is in fact an entirely timeless event (VI [10], Ch. 6, l. 19). Once the sensible world, particularly the human body, has been constituted, the Soul in the acts of incarnation becomes submerged in the realm of the temporal. The clash between a pessimistic and an optimistic evaluation of the emanative process can now be repeated in Plotinus's evaluation of incarnation.


The Platonist cannot easily ignore either the myth of the Phaedrus, implying that souls "fall" by some kind of failing, or the otherworldly mood of the Phaedo, implying that the soul should try to flee the body and be polluted as little as possible by it. But just as it is difficult for a Platonist to forget that according to the Timaeus, the first incarnation of the soul is the work of the divine artisan himself and, thus, a blameless event, so it is equally difficult for him to forget the myth of the Republic, according to which embodiment seems to be the result of some universal necessity. As a result, Plotinus had to resolve a contradiction. Sometimes he did so by trying to prove that there is no true contradiction (IV 8 [6], Ch. 5). But recognizing that such an assertion is in the last resort unsatisfactory, even when it is assumed that only part of the Soul descends (IV 7 [2], Ch. 13, l. 12; IV 8 [6], Ch. 7, l. 7), he adopted a theory that he explicitly claims as his innovation (he otherwise presents himself as an orthodox Platonist).

According to this theory, a true fall has never taken place. Actually, even when in a body, the soul still lives its original "celestial" life and remains unseparated from Intelligence. Only we are not aware of this "hidden" life of the soul; in other words, we are partly unconscious of what happens in our minds (IV 8 [6], Ch. 8). What is true of the Soul in relation to Intelligence is even truer of the relation between our embodied selves and Intelligence. Not even when present in us does Intelligence discontinue its activity (V 1 [10], Ch. 12).

Plotinus also makes an optimistic and a pessimistic evaluation of the deterioration that has taken place in the soul as a result of its incarnation. On the whole, he tries to prove that no real deterioration has taken place, but he often feels that he must find reasons why the soul should try to escape the body and return home. One of these reasons is that the body prevents the soul from exercising the activity peculiar to it (IV 8 [6], Ch. 2, l. 43), which means, of course, that some deterioration does take place.


There are some dualistic traits in the philosophy of Plotinus, particularly the recognition of the Indeterminate Dyad (as opposed to the One), to which he also refers simply as the Indeterminate (II 4 [12], Ch. 11, l. 37). Aristotle presented Plato's philosophy as a dualistic system, identifying the Indeterminate Dyad with Plato's receptacle and also with matter, in his own sense of the word; in other words according to him, Plato's ideas, being the product of the interaction of the two opposite principles, contain matter. Aristotle furthermore asserted that the Indeterminate Dyad is also the principle of evil. Plotinus is willing to recognize the Indeterminate as a second principle and to see in matter the principle of evil, but he refuses to recognize the existence of evil in the realm of Intelligence (ideas). He is thus forced to recognize the existence of two kinds of matter, one in the realm of the sensible and the result of the last emanative step, the other in the realm of Intelligence ("intelligible matter"), which does not have some of the properties usually associated with matterspecifically, it is not evil. He justifies this by the assumption that everything, including matter in the physical world, must have its archetype in the realm of Intelligence (II 4 [12], Chs. 2f., 11, 14). Whether the assumption of intelligible matter can be reconciled with monism appears dubious; its "origin" is never made clear by Plotinus.

As to matter in the realm of the sensible, it is sheer indeterminacy, incorporeal, and, thus, different from the Stoic conception of matter (II 4 [12], Chs. 1, 4, 9, 10). It remains as unaffected by the ideas (or "ratios," logoi, by which Stoic term Plotinus often designates ideas as present in the soul qua formative powers) as the mirror is unaffected by what it reflects. Precisely because this matter is indeterminate, it is evil (II 4 [12], Ch. 16, l. 19), which means that evil is not something positive, but sheer privation.

There is a strange parallelism between matter and the One, because both are entirely indeterminate. Therefore, they both elude ordinary concepts, and Plotinus faces the question of what it means to know them. As far as matter is concerned, Plotinus likens it sometimes to darkness, and the mental act by which we grasp it to "unthinking thinking," or the soul's reduction to indefiniteness (II 4 [12], Chs. 6, 11)concepts reminding us of Plato's pseudo thinking (nothos logismos ), declared by him to be the appropriate way to think the receptacle.

knowledge of the one

But much more important for Plotinus is the problem how the One, in spite of its being ineffable, can be known. In the pseudo(?)-Platonic Epinomis (992b), the author insists that in order to know the One (whatever "knowledge" means here), the soul must itself become one; the Platonic Letters also seem to teach some kind of suprarational insight. Perhaps starting from passages such as these and also from passages in Aristotle and Theophrastus in which some kind of infallible knowledge of certain objects is described as a kind of touching (thinganein ), Plotinus asserts that to "know" the One means to become one with it, which the soul can accomplish only by becoming as simple or as "alone" as the One. In the moment of such a union the soul has become God or, rather, is God; the soul has reascended to its original source (VI 9 [9], Ch. 9f.). Among the terms Plotinus uses to describe this condition are ecstasy, simplicity, self-surrender, touching, and flight of the alone to the alone (VI 9 [9], Chs. 3, 11). This ecstasyrepeatedly experienced by Plotinus himselfis undoubtedly the climactic moment of man's life. It is not expressible in words (compare Plato, Epistle VII, 341d); only he who has experienced it knows what it means to be ravished away and full of God.

For this reascent man prepares himself by the acquisition of all the perfections (virtues, aretai ). However, each of these perfections acquires different meanings according to the level on which man's spiritual life takes placethus, there is a social fairness, above it another kind of fairness, and so on. Man also prepares himself by the exercise of dialectics (I 2 [19]; I 3 [20]). The preliminary stages of achievement Plotinus calls "becoming Godlike" (I 6 [1], Ch. 8), a condition often described by Platonists preceding Plotinus as the ultimate goal of Plato's philosophy.

free will and demonology

Among the other topics treated in this period, Plotinus's defense of the freedom of the willonly "reasonable" souls are free; others are subject to fate, εμαρμένη (III 1 [3])and his demonology deserve special mention. In regard to demonology Plotinus tries to steer a middle course between two theories, one identifying demons with the supreme parts of our soul, and the other assuming the existence of demons as extrapsychical beings (III 4 [15]).

Second Period, 263268


More than two-fifths of Plotinus's total literary output was produced during the brief period between 263 and 268, when Porphyry was studying with Plotinus. Perhaps Porphyry's presence worked as a powerful stimulus. A considerable part of the output of this period is devoted to polemics with other schools, notably on the doctrine of categories and against Gnosticism.


Plotinus rejects both the Aristotelian and the Stoic versions of this doctrine, adhering to the principle that there can be no categories common to the realms of the sensible and the intelligible. In application to the realm of the sensible he corrects and modifies Aristotle's categories; to the realm of Intelligence he tries to apply Plato's five generabeing, identity, diversity, rest, and change (VI 13 [4244]).

Ideal Numbers

Aristotle presented Plato as professing the existence of ideal numbers (twoness, threeness, and so on, as distinguished from ordinary numberstwo, three, and so on). And he devoted much effort to the criticism of the theory of ideal numbers. Plotinus defends the theory of ideal numberswhich differ from nonideal numbers in that they do not consist of addible unities and are therefore not addible themselves (V 5 [32], Ch. 4)and, objecting to any nominalist or abstractionist theory of numbers, attributes to them subsistence. Specifically, after having divided the realm of Intelligence into three layersBeing, Intelligence (in a restricted sense of the word), and the original Living Beinghe assigns ideal numbers to the uppermost layer and explains that only because of their existence can Being divide itself into beings (VI 6 [34]), Chs. 8, 16). In this context he also introduces a peculiar concept of infinity: The truly infinite is a thing that has no limits imposed on it from without but only from within (VI 6 [34], Chs. 17f., but compare V 5 [32], Ch. 4).

Polemic Against Gnosticism

Of all the polemics of Plotinus, the most significant is the one against Gnosticism. One could say that when facing Gnostic pessimism point-blank, Plotinus overcompensates for the pessimistic and Gnostic strand present in himself and responds with an almost unlimited optimism. The fundamental mood underlying Gnosticism is alienation from a hostile world, and Gnosticism undertakes to explain this mood and to open the road to escape from the world. The explanation is in the form of a history of the origin of the visible cosmos; according to Gnosticism, this cosmos is the result of the activity of an evil god sometimes identified with the Creator-God of the Old Testament or with Plato's divine artisan. This evil god is only the last in a succession of beings. The manner in which this succession takes place consists in a number of voluntary acts by which divinities of an ever lower order originate. The relation between these deities is often personal, based on such traits as curiosity, oblivion, daring, ambition. Man, as he exists in this evil world, contains in himself a spark of what was his original, divine substance, now imprisoned in his body owing to the scheming of the evil god. At a certain moment a messenger-savior in some way breaks the power of the evil god and makes it possible for those who hear the whole story (acquire gnosis) to regain their original standing and free themselves from the tyranny of the evil god.

Plotinus treats Gnosticism as a strictly philosophic system. He simply compares its doctrines with his own and with those of Plato; its salvationary aspects are of little interest to him (compare III 2 [47], Ch. 9). In the succession of divine beings he sees only a superfluous multiplication of the three hypostases of his own system (compare V 5 [32], Chs. 1f.). To the cosmic drama that results in the creation of the visible cosmos he opposes his view of a totally undramatic, unconscious emanation, a product of necessity without arbitrariness and, contradicting even Plato's Timaeus (40b45a), without planning (V 8 [31], Ch. 7) and, therefore, entirely blameless. The cosmos, product of the activities of the Soul (or Intelligence or both), he considers to be beautiful. Whereas Gnosticism sees the visible universe filled with spirits inimical to man, most outstanding among them being the rulers of the celestial bodies (planets), Plotinus sees in these spirits powers related to man in brotherly fashion. What is true in Gnosticism can, according to him, be found in Plato. The Gnostic objection that Plato did not penetrate the mysteries of the intelligible world Plotinus considers ridiculously presumptuous (II 9 [33]; compare V 8 [31], Ch. 8).


In the second period Plotinus was also concerned with the problems inherent in his own system, especially with the relation between the intelligible world and the sensible world and with the structure of the intelligible world.

The One

First, Plotinus tries to elucidate the nature of the One still further. He does this particularly in the context of a discussion concerning the nature of human freedom, in which he also asks whether the One should be considered as a necessary being or as a free one (ens necessarium or ens liberum )in theistic terms, whether God must exist or has freely chosen to exist. In what is perhaps his most profound theological discussion, Plotinus tries to establish the concept of the One as Lord of itself and thus not having to serve even itself, so that in the One freedom and necessity coincide (VI 8 [39], Chs. 721). And without any vacillation he excludes any kind of consciousness from the One (V 6 [24], Chs. 2, 4f.).

Intelligence and Soul

As far as Intelligence is concerned, Plotinus reiterates his doctrine that it contains ideas within itself (V 5 [32], Chs. 1f.), and he again tries to explain how, in spite of being one, it still contains multiplicity (VI 4 [22], Ch. 4; VI 5 [23], Ch. 6). With regard to souls Plotinus tries to explain how they can remain distinct from one another although they all are only one soul (VI 4 [22], Ch. 6; IV 3 [27], Chs. 18; compare IV 9 [8], Ch. 5).

Both Intelligence and Soul are supposed to be present in the sensible world and, therefore, present in what is extended, although they themselves are not extended. Starting from the famous discussion in Plato's Parmenides (131b), in which the attempt is made to explain how one idea can be present in many particulars, Plotinus tries to show that just because Intelligence and Soul are not extended, they can be omnipresent and ubiquitous in what is extended (VI 4 [22], especially VI 5 [23], Ch. 11). And also in this context he tries to establish the concept of differentiated unity (VI 4 [22], Ch. 4), that is, the noncontradictory character of "one" and "many."

Intelligence, Soul, Change

Probably the most formidable difficulty facing Plotinus is the result of his theory treating Intelligence and Soul as metaphysical principles on the one hand and as present in man on the other (that is, as both transcendent and immanent) and, therefore, in some way engaged in mental life, particularly in sensing and remembering. As metaphysical principlesthat is, members of the realm of the intelligibleIntelligence and Soul should be unchangeable, whereas in man they seem to be involved in change. From this difficulty Plotinus tries to extricate himself in many ways, of which two will be presented.

On the one hand he keeps even the human soul away as much as possible from the processes of sensing, remembering, desiring, experiencing pleasure and pain, and so on (III 6 [26], Ch. 15). Sometimes he insists that the soul simply notices all these processes without being affected by what it perceives (IV 6 [41]; IV 4 [28], Ch. 19). Sometimes he insists that it is not the soul itself but only some trace of it which is engaged in these activities (IV 4 [28], Chs. 18f.; compare VI 4 [22], Ch. 15, l. 15), and this ties in with the theory that the soul did not reallyor not in its entiretydescend (VI 4 [22], Ch. 16). Sometimes he introduces the concept of a double soul, a higher and a lower, with only the lower being changeable. This doubling of the soul Plotinus carries to such extremes that he assumes two imaginative faculties and two faculties of memory, each belonging to its respective soul and each remembering in a different manner and different events. This is particularly the case after man's death; the higher soul no longer remembers anything it experienced while in the body, whereas the lower soul still remembers (IV 3 [27], Chs. 2532; IV 4 [28], Ch. 1, l. 5). Sometimes he suggests that all the mental activities involving change happen not to the soul but to the composite of soul and body (IV 4 [28], Ch. 17), leaving undecided how anything can affect a whole without affecting the part that belongs to it.

On the other hand, when it comes to Intelligence and Soul as metaphysical principles (and even to the world soul and astral souls), Plotinus disallows them memory entirely (IV 4 [28], Chs. 617). As to sensing, he distinguishes two kinds, one serving such practical purposes as self-preservation, the other purely theoretical; it is only the theoretical kind that he ascribes to metaphysical entities, the implication obviously being that this kind of sensation does not cause any change in the perceiver (IV 4 [28], Ch. 24). Why they should still be called Intelligence and Soul remains somewhat unclear. Perhaps the most striking example of the real effects of the Soul's falling away from Intelligence (despite everything said by Plotinus to minimize these effects) is that the cosmic soul, as it falls away, engenders time because of an inability to contemplate the totality of Intelligence simultaneously (III 7 [45], Ch. 11).


The difficulties created for the explanation of the cognitive aspects of man's mental life without the assumption of a real change (passibility) of the soul return with even greater significance in the field of ethics. If there is no actual fall of the soul and if no deterioration of its nature has taken place as the result of incarnation (III 6 [26], Ch. 5), why is purifying the soul necessary? Yet the concept of purification plays a central role in the ethics of Plotinus (compare I 6 [1]; I 2 [19]); he even describes the perfectionswisdom, self-control, justice, courageas purifications. Plotinus tries to help himself by a metaphor: The soul is merely covered with mud, which, however, has never penetrated it. According to another explanation, what the soul has acquired because of its fall is nothingness, and all it has to do, therefore, is to get rid of nothing (VI 5 [23], Ch. 12, ll. 1623).

Cosmic Sympathy

The insistence that memory and sensation, in their ordinary senses, are absent from the realm of Intelligence and even from that of the celestial sphere Plotinus explains with his theory that the universe is one animated organism. The sympathy existing among parts of one organism make memory and sensation superfluous, since the mutual affection need not be perceived. This leads to characteristic explanations of the efficacy of magic, prayers, and astrology. All these activities (and prophecies) are made possible by the fact that each part of the universe affects the others and is affected by them, not by mechanical causation nor by influencing the will of deitiesparticularly starsbut exclusively by mutual sympathy (IV 3 [27], Ch. 11; IV 4 [28], Chs. 40f.). In this doctrine of sympathy many scholars see the influence of the Stoa, particularly Posidonius, on Plotinus.


As to matter, Plotinus in the writings of this periodwith less ambiguity than in other periodscharacterizes it as the result of the last step of the emanative process, thus fully preserving the monistic character of his system (II 5 [25], Ch. 5; compare I 8 [51], Ch. 7). Some other problems discussed by Plotinus are distinctly occasional pieces and somewhat peripheral with regard to the system. Thus, we find a theory of vision, explained by sympathy (IV 5 [29]; II 8 [35]); a discussion of the Stoic concept of the complete interpenetration of bodies (II 7 [37]); a cosmology without the assumption of ether (II 1 [40]).

Third Period, 268270

As is to be expected, some earlier themes recur in the third period. In fact, one of the essays of the third period (V 3 [49]) contains what is perhaps the most comprehensive presentation of the basic tenets of Plotinus's philosophy. Plotinus proves that there must be a One preceding all multiplicity and that this One must be ineffable (V 3 [49], Chs. 12f., 17). To explain its presence in us and the fact that we know about it although we do not know it, he says that those full of and possessed by the divine also feel that something greater than themselves is present in them, although they cannot say what it is (V 3 [49], Ch. 14). Once more facing the problem of how the One, which is absolutely simple, can be the source of multiplicity, Plotinus is on the verge of admitting that the One is at least potentially (though it is a potentiality sui generis) many (V 3 [49], Chs. 15f.; compare VI 5 [23], Ch. 9). The same essay contains what is probably the most detailed and the most impressive description of the upward journey of the soul to reach the goal of ecstatic union, described by the formula "through light light" (V 3 [49], Ch. 17, ll. 2837; compare V 5 [32], Chs. 49). As advice on how to achieve this union, Plotinus says "strip yourself of everything" (V 3 [49], 17, l. 38). Furthermore, Plotinus still feels he must prove that ideas are not external to Intelligence (V 3 [49], Chs. 513).

On the whole, the writings of Plotinus's last period are dominated by two themes. The first concerns theodicy, the origin and justification of evil, and the second asks what man's true self is.


To explain the origin of evil, Plotinus tries to reconcile the view that matter, though void of any quality and actually only deficiency, is still evil in some sense of the word and is the source of all evil (I 8 [51], Chs. 8, 10). In so doing, he sometimes comes dangerously close to the Gnostic theory that matter imprisons the soul (I 8 [51], Ch. 14, ll. 4850) and to a completely dualistic system (I 8 [51], Ch. 6, l. 33). Nevertheless, his optimism is particularly strong in this period; he has high praise for the beauty of the visible cosmos (III 2 [47], Ch. 12, l. 4), and rejects the idea of an evil creator of the cosmos (III 2 [47], Ch. 1). His theodicy is a blend of Platonic arguments, drawn especially from Book X of the Laws, and Stoic arguments. Perfection of the whole demands imperfection of the parts (III 2 [47], Chs. 11, 17; III 3 [48]) and the existence of evil (I 8 [51], Chs. 815). At the same time he minimizes the importance of evil by insisting that it exists only for the wicked one (III 2 [47], Ch. 6). Furthermore, he points out that the cosmic order rewards and punishes everybody according to his merits and assigns each one an appropriate place, thus making for a completely harmonious whole (III 2 [47], Ch. 4). Ultimately, his theodicy is based on convictions characteristic of most theodiciesthat to designate a particular as evil is to lose sight of the whole, that everything participates in the good as far as it can, and that evil is only absence of the good (III 2 [47], Chs. 3, 5; I 8 [51], Chs. 15).


Closely connected with the problem of theodicy is the problem of providence. Plotinus insists on the all-pervasive character of providence, thus rejecting Aristotle's dichotomy of the universe into a sublunar sphere dominated by necessity and a supralunar world to which providence is restricted. He replaces Aristotle's distinction by the dichotomy of good and wicked men; only the wicked are subject to necessity (III 2 [47], Ch. 9; compare III 1 [3], Chs. 810). But this providence is entirely impersonal (compare VI 7 [38], Ch. 1) and actually coincides with the order of the universe.

true self and happiness

The second major theme of Plotinus's last period is that of ascertaining what man's true self isthat is, of ultimately obeying the divine command "Know thyself." Attendant subproblems are the explanations of wherein man's true happiness consists and of the concept of self-knowledge. It is extremely difficult for Plotinus to give a consistent account of what constitutes man's true self. He cannot simply identify it with Intelligence or Soul (as he did in IV 7 [1], Ch. 1, l. 24 or in I 4 [46], Chs. 816, where it is identified with the "higher" soul), precisely because both, in their character of metaphysical entities, remain transcendent; however, he rejects the idea that man is truly the composite of soul and body (I 4 [46], Ch. 14, l. 1) because this would grant the body too much importance. One of the solutions favored by Plotinus is that Intelligence is man's true self, but only if and when he succeeds in identifying himself with it. On the other hand, no such identification is actually necessary, because Intelligence is always in and with us even though we are not aware of it. (Mutatis mutandis this can also be applied to the relation of man and whatever is to be conceived the highest divinity: compare VI 5 [23], Ch. 12). Once more the concept of the unconscious plays a decisive role in the system of Plotinus (I 4 [46], Chs. 9f.; V 3 [49], Chs. 3f.). All this ties in with the idea that self-knowledge occurs only when the subject, the act, and the object of knowledge coincidewhich takes place only on the level of Intelligencewhereas neither man as a whole nor Soul can possess full self-knowledge (V 3 [49], Chs. 3, 6). The One is, of course, above any kind of self-knowledge (V 3 [49], Chs. 1013).

The thesis that only Intelligence is man's true self (if and when he makes full use of it) serves also as a basis for a discussion of the problem of man's happiness. If by "man" we mean the composite of body and soul, man cannot experience happiness, nor can he if he is body alone. However, if by "man" we mean the true self, it is obvious that happiness consists in the exercise of Intelligencethat is, in contemplation. But as the activity of Intelligence is uninterrupted (here in the argument Plotinus switches from Intelligence as immanent to transcendent Intelligence; see I 1 [53], Ch. 13, l. 7) man is actually always happy, although he may remain unconscious of it (I 4 [46], Chs. 4, 9, 1316). Why this should apply only to the sage remains unclear.

The formidable problem of how the soul, the essence of which is unchangeability, can ever become evil also vexed Plotinus to the end (compare I 8 [51], Ch. 4, 12, 15). In the work of his last period he explains that as the soul at its descent acquires additional parts, evil resides only in them. Thus, the ethical task of man is not so much to separate the soul from the body as it is to separate it from these adventitious parts (I 1 [53], Ch. 12, l. 18). In this context the problem of who is the subject of punishments in afterlife also emerges; Plotinus answers that it is that "composite" soul (I 1 [53], Ch. 12). Why we should call soul an entity that is or can become evil, "suffer" punishment, and so on, after Soul has been presented as belonging to the realm of the unchangeable, remains unanswered; so do virtually all questions resulting from the dual character of Intelligence and Soul as metaphysical (transcendental) entities on the one hand and human (immanent) entities on the other.

There is almost something providential in the fact that the very last of Plotinus's essays, written at a time when death was approaching him, reasserts that all things participate in the One (the Good) and discusses the question of how to reconcile the two theses that life is good and yet death no evil, though it deprives us of something good (I 7 [54], Ch. 3). The battle between the pessimistic and the optimistic strands in Plotinus continued to the very end of his activity. Optimism ultimately won: Life is goodthough not for the wicked one; death is good, because it will permit the soul to live an unhampered life.

See also Alcinous; Antiochus of Ascalon; Aristotle; Categories; Cosmos; Emanationism; Evil, The Problem of; Gnosticism; Good, The; Neoplatonism; Nous; Numenius of Apamea; Origen; Plato; Platonism and the Platonic Tradition; Porphyry; Posidonius; Pythagoras and Pythagoreanism; Socrates; Stoicism.


works by plotinus

The standard edition of the Greek text of the Enneads and of Porphyry's Life of Plotinus is by Paul Henry and Hans-Rudolf Schwyzer, Plotini Opera, in 3 vols. (Oxford: Clarendon Press, 19641982) (editio minor with concise apparatus). For full critical apparatus and an English translation of the important Arabic tradition see their editio maior, in 3 vols. (Paris: Desclée de Brouwer, 19511973).

Modern translations (some including ancient text and/or valuable notes) are available in English by A. H. Armstrong, in 7 vols. (Cambridge, MA, and London: Harvard University Press and Heinemann, 19661988); in French by É Bréhier, in 6 vols. (Paris: Belles Lettres, 19241938); in German by R. Harder, R. Beutler, and W. Theiler, in 5 vols. (Hamburg: F. Meiner, 19561962); in Spanish by J. Igal, in 3 vols. (Madrid: Gredos, 19821998); and in Italian by M. Casaglia, C. Guidelli, A. Linguiti, and F. Moriani, in 2 vols. (Torino: Unione Tipografico-Editrice, 1997). A new French translation of individual treatises with extensive commentary, under the direction of Pierre Hadot (Paris: Cerf, 1988), comprises, so far, 8 vols.

works on plotinus

A complete lexicon for Plotinus' writings is J. H. Sleeman and Gilbert Pollet, Lexicon Plotinianum (Leiden: Brill, 1980). For a comprehensive bibliography, see Richard Dufour, Plotinus: A Bibliography 19502000 (Leiden: Brill [Phronesis, vol. 46, No. 3], 2001). This is updated in:

general works

Gerson, Lloyd P. Plotinus. London: Routledge, 1994.

Hadot, Pierre. Plotinus, or the Simplicity of Vision. Translated by M. Chase, with an introduction by A. I. Davidson. Chicago, IL: University of Chicago Press, 1993.

O'Meara, Dominic J. Plotinus: An Introduction to the Enneads. Oxford: Clarendon Press, 1993.

Rist, John M. Plotinus: The Road to Reality. Cambridge, NY: Cambridge University Press, 1967.

Schwyzer, Hans-Rudolf. "Plotinos." In Realencyklopädie der classischen Altertumswissenschaft, edited by A. Pauly and G. Wissowa. Vol. 21 (1951): 471592, with supplement in SupplementBand, 15 (1978): 310328.

commentaries on individual treatises

Atkinson, Michael. Ennead V, 1, On the Three Principal Hypostases: A Commentary with Translation. Oxford: Oxford University Press, 1983.

Fleet, Barrie. Ennead III, 6, On the Impassivity of the Bodyless. Oxford: Clarendon Press, 1995.

Meijer, P. A. Plotinus On the Good or the One ( Enneads VI, 9): An Analytical Commentary. Amsterdam: Gieben, 1992.

Tornau, Christian. Plotin: Enneaden VI, 4-5 (2223): Ein Kommentar. Stuttgart: Teubner, 1998.

studies of detail

Adamson, Peter. The Arabic Plotinus: A Philosophical Study of the Theology of Aristotle. London: Duckworth, 2002.

Armstrong, A. H. Plotinian and Christian Studies. London: Variorum Reprints, 1979.

Blumenthal, Henry J. Plotinus' Psychology: His Doctrines of the Embodied Soul. The Hague: Nijhoff, 1971.

Bussanich, John R. The One and its Relation to Intellect in Plotinus: A Commentary on Selected Texts. Leiden: Brill, 1988.

Corrigan, Kevin. "Body's Approach to Soul. An Examination of a Recurrent Theme in the Enneads." Dionysius 9 (1985): 3752.

Corrigan, Kevin. Reading Plotinus: A Practical Introduction to Neoplatonism. West Lafayette IN: Purdue University Press, 2005.

Dillon, John M. "Plotinus and the Transcendental Imagination." In his Religious Imagination. Edinburgh: Edinburgh University Press, 1986.

Dillon, John M. "Plotinus, the first Cartesian?" Hermathena 149 (1990): 1931.

Emilsson, Eyjólfur Kjalar. Plotinus on Sense-Perception: A Philosophical Study. Cambridge, U.K.: Cambridge University Press, 1988.

Emilsson, Eyjólfur Kjalar. "Plotinus on the Objects of Thought." Archiv für Geschichte der Philosophie 77 (1995): 2141.

Ferwerda, R. La signification des images et des métaphores dans la pensée de Plotin. Groningen: J. B. Wolters, 1965.

Gerson, Lloyd P., ed. The Cambridge Companion to Plotinus. Cambridge, NY: Cambridge University Press, 1996.

Hadot, Pierre. "Les niveaux de la conscience dans les états mystiques selon Plotin." Journal de Psychologie Normale et Pathologique 77 (1980): 243266.

Igal, Jesus. "The Gnostics and 'The Ancient Philosophy' in Porphyry and Plotinus." In Neoplatonism and Early Christian Thought: Essays in Honour of A. H. Armstrong, edited by H. J. Blumenthal and R. A. Markus. London: Variorum Publications, 1981.

Jackson, B. Darrell. "Plotinus and the Parmenides. " Journal of the History of Philosophy 5 (1967): 315327.

Kalligas, Paul. "Forms of Individuals in Plotinus: a Re-examination." Phronesis 42 (1997): 206227.

McCumber, J. "Anamnesis as Memory of Intelligibles in Plotinus." Archiv für Geschichte der Philosophie 60 (1978): 160167.

O'Brien, Denis. Plotinus on the Origin of Matter: An Exercise in the Interpretation of the Enneads. Napoli: Bibliopolis, 1991.

O'Daly, G. J. P. Plotinus' Philosophy of the Self. Dublin: Irish University Press, 1973.

Rist, John M. "Monism: Plotinus and Some Predecessors." Harvard Studies in Classical Philology 69 (1965): 329344.

Schibli, Hermann S. "Apprehending our Happiness. Antilepsis and the Middle Soul in Plotinus, Ennead I, 4, 10." Phronesis 34 (1989): 205219.

Schniewind, Alexandrine. L'éthique du sage chez Plotin: Le paradigme du spoudaios. Paris: J. Vrin, 2003.

Schroeder, Frederic M. Form and Transformation: A Study in the Philosophy of Plotinus. Montréal, London: McGill-Queen's University Press, 1992.

Sorabji, Richard. "Myths about Non-propositional Thought." In Language and Logos: Studies in Ancient Greek Philosophy Presented to G. E. L. Owen, edited by M. Schofield and M. C. Nussbaum. Cambridge, U.K.: Cambridge University Press, 1982.

Strange, Steven Keith. "Plotinus, Porphyry and the Neoplatonic Interpretation of the Categories." In Aufstieg und Niedergang der römischen Welt: Geschichte und Kultur Roms im Spiegel der neueren Forschung, edited by Wolfgang Haase. Vol. II, 36.2. Berlin: De Gruyter, 1987.

Strange, Steven Keith. "Plotinus on the Nature of Eternity and Time." In Aristotle in Late Antiquity, edited by L. P. Schrenk. Washington DC: The Catholic University of America Press, 1994.

Philip Merlan (1967)

Bibliography updated by Paul Kalligas (2005)

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