Plotinus was the founder of Neoplatonism, the dominant philosophical movement of the Graeco-Roman world in late antiquity, and the most significant thinker of the movement. He is sometimes described as the last great pagan philosopher.His writings, the so called Enneads, are preserved as whole. While an earnest follower of Plato, he reveals other philosophical influences as well, in particular those of Aristotle and Stoicism. Plotinus developed a metaphysics of intelligible causes of the sensible world and the human soul. The ultimate cause of everything is 'the One' or 'the Good'. It is absolutely simple and cannot be grasped by thought or given any positive determination. The One has as its external act the universal mind or 'Intellect'. The Intellect's thoughts are the Platonic Forms, the eternal and unchanging paradigms of which sensible things are imperfect images. This thinking of the forms is Intellect's internal activity. Its external act is a level of cosmic soul, which produces the sensible realm and gives life to the embodied organisms in it. Soul is thus the lowest intelligible cause that immediately is immediately in contact with the sensible realm. Plotinus, however, insists that the soul retains its intelligible character such as nonspatiality and unchangeability through its dealings with the sensible. Thus he is an ardent soul-body dualist. Human beings stand on the border between the realms: through their bodily life they belong to the sensible, but the human soul has its roots in the intelligible realm. Plotinus sees philosophy as the vehicle of the soul's return to its intelligible roots. While standing firmly in the tradition of Greek rationalism and being a philosopher of unusual abilities himself, Plotinus shares some of the spirit of the religious salvation movements characteristic of his epoch.
We possess a fairly reliable account of Plotinus' life and writings by Porphyry, his student and editor. Porphyry composed a biography, On the Life of Plotinus and the Order of his Books, which prefaced his posthumous edition of Plotinus' writings. At the age of twenty eight Plotinus began his philosophical studies in Alexandria under a certain Ammonius (often called Ammonius Saccas, and not to be confused with Ammonius the teacher of Plutarch of Chaeronea (§1) or with Ammonius, son of Hermeas) and studied with him for several years. After making a futile attempt at a journey to the East in order to acquaint himself with the philosophy of Persia and India, he settled in Rome at the age of forty. He established a school in Rome and stayed there except during his final illness.
The extant corpus of Plotinus' writings is one of the largest we have of any ancient philosopher, and we probably possess everything he wrote. His works are treatises, written in Greek, that grew out of discussions in his school, and vary greatly in length and scope. Porphyry arranged the treatises according to subject matter into six 'enneads' - six sets of nine treatises. In order to arrive at this division he had to split some treatises. Conventionally, references to the Enneads are often given only in numbers: 'V 3(49).2, 14-16', for instance, means '5th Ennead, 3rd treatise (which is number 49 on Porphyry's chronological list of Plotinus' writings), chapter 2, lines 14 to 16'.
Plotinus' thought grows out of a tradition of so-called Middle Platonism (see Platonism, Early and Middle), which developed during the first two centuries ad. The Middle Platonists interpreted Plato dogmatically: that is, unlike the Academic sceptics, they took Plato to hold definite views. Their interests lie primarily in metaphysics and psychology, broadly understood. Even if they show obvious influence from other schools of thought - many Aristotelian and Stoic notions had become a part of the language of philosophy itself - Middle Platonists believe that the fundamental philosophical truths are to be found in Plato. Plotinus shares these general characteristics.
It is sometimes said that Plotinus is a system builder who never reveals his whole system in an organized way, and that the system must be inferred from bits and pieces here and there in his writings. Another common dictum is that every one of his treatises presupposes all the rest and the whole system. There is something to these claims. However, even if behind Plotinus' writings there lies a more organized comprehensive view than meets the eye, his mind is not that of the rigid system builder. His philosophical genius rather consists in the exceptional sensitivity and depth of thought with which he addresses difficulties inherent in the Platonic tradition.
Plotinus works with a fundamental dichotomy between the intelligible (to noton) and the sensible (to aisthton). The intelligible world is the realm of the real (in the sense of existing independently, being by virtue of itself), and it is unchanging and non-spatial. The sensible world, by contrast, is an unreal, changeable image of the intelligible, expressed in spatial extension. Within both these realms there are further divisions, so that the result is a hierarchical ontology. At the apex of the hierarchy is the One (also referred to as the Good), then, in descending order, are Intellect and Soul (see Nous; Psych). These three levels, the One, Intellect and Soul, are often called hypostases and their names are customarily capitalized. Particular souls - of people, animals and the soul of the sensible world itself - also belong to the intelligible order but are in close contact with the sensible realm. The hierarchy continues in the sensible world, where organisms, forms in matter (that is, sensible qualities), inanimate bodies and matter constitute the main stages. As is evident from the non-spatial nature of the intelligible world, such terms as 'hierarchy', 'above' and 'below' in the present context are not to be understood spatially but as indicating ontological priority.
The One, Intellect, Soul, and, with certain qualifications to be explained below, matter too, are explanatory postulates of the kind the Greek philosophers called principles (archai) (see Arch). Plotinus takes a strong realist position with regard to his principles: not only do they exist, they are more real, exist in some fuller sense, than that which they were meant to explain. Inorganic bodies, organisms and their functions, and human consciousness are phenomena to be accounted for in terms of the principles.
Considerations such as the following help explain the plurality of stages in the Plotinian hierarchy. Once a distinction has been made between what is to be accounted for and a principle that explains it, questions may arise about the principle itself: the principle itself may turn out to have features that stand in need of an explanation. A further principle must then be assumed to account for the first one. The process of seeking further principles continues until a principle that needs no further explanation is reached, a principle about which no further questions can be asked. For Plotinus this ultimate principle is the One.
Plotinus generally holds that the principles themselves must have the features they explain. For instance Soul, which is the principle of life, is itself alive. Moreover, the principles ideally have these features in such a way that it is pointless to ask why they have them. The principle possesses in and of itself what other things possess as a derived and contingent feature and hence one that requires explanation. Plotinus frequently expresses this by saying of a principle that it is such and such in itself (en heautoi), whereas other things have the same feature as in another (en alloi).
Unity is a central concept in Plotinus' doctrine: each stage of the hierarchy has a characteristic kind of unity, with the One as the absolutely simple ultimate principle which is the cause of all other unity that there is, and thereby, the cause of everything else whatsoever. To be is to be one thing, to be unified, and the more unified something is the more of a being it is. The most striking feature of the world of everyday experience is in fact the unity of it as a whole and of individual objects, especially living things, in it. The organization, regularity and beauty that are evident in the world of everyday experience, all of which may be said to express its unity, cannot be explained in terms of its constituent parts. The latter are what is unified and their unity is an imposed feature which must come from elsewhere. The unity revealed in the sensible world is in Plotinus' view far from perfect but it gives the sensible world the reality it has. The same may be said of our experiences of ourselves: introspection will show that the human soul has a more perfect kind of unity than anything pertaining to the body, although even the soul does not have unity of itself (IV 2(4).2; IV 7(2).6-7). Thus, the world of everyday experience, both the external world and our mental life, point beyond themselves to a higher level of reality which is its principle.
This process of going upwards from everyday phenomena obviously draws on Plato's dialectic as described for instance in the Symposium and the Republic. There are many instances of such a procedure in the Enneads, the most famous being Plotinus' first treatise, On Beauty (I.6911)), where he builds on Diotima's speech in the Symposium. This treatise has been influential in art, especially during the Renaissance. The ascent from the beauty of corporeal things to the Beautiful itself is, as one would expect, interpreted in terms of the Plotinian hierarchy and general doctrine of intellectual ascent (see §6). There is a noteworthy deviation from Plato's views of the arts as expressed in the Republic in that for Plotinus art does not imitate nature but operates parallel with nature (I 6.3; V 8(31).1). Thus, the artist uses the intelligible world directly and gives it an expression in the sensible world.
Ignoring the intermediate stages for the moment, the self-sufficiency of the principles with regard to the features they explain, together with the claim that whatever else there is presupposes unity, leads to the highest principle, the One, which is both absolutely simple and unique (V 4(7).1). The doctrine of the One, even if adumbrated by the tradition before Plotinus, is probably his most significant innovation. Some of his Middle Platonist predecessors believed in a simple first principle, but like Aristotle they thought that this simple principle was an intellect of some sort. In Plotinus' view, by contrast, Intellect involves plurality: there is plurality in thought because there is at least a conceptual distinction between the thought and its object, and what is thought is in any case varied (see, for example, V 3(49).10).
The One is unique and involves no variation or limitation. From this it follows that the One cannot be given any positive characterization. It cannot be grasped by thought or known in its true nature since any thought of it distorts in so far as the thought is bound to be composite (V 5(32).6; VI 9(9).4). It would even be inappropriate to say of the One that it is, or that it is one inasmuch as such expressions indicate something unified rather than the absolutely simple nature that gives unity to whatever is unified (VI 9.5). Nevertheless, it is possible to approach the One and even become one with it in a kind of non-cognitive union, a 'vision' which defies all description (VI 9.8-11). It is as a result of this doctrine of a union with the ultimate principle, a union which transcends conceptualization, that Plotinus has been called a mystic. Without wishing to deny the significance of this union with the One, it must be said that it does not play a major role in his writings. In spite of the fact that the One is ineffable, Plotinus manages to say a great deal about it. This is however not a real inconsistency: the ineffability of the One is the thesis that one cannot predicate anything of it since any predication would imply the One's composition. This does not mean one cannot talk about its relations to other things and in general about its role in the ontology.
Even if there are precedents in Plotinus' tradition for a supreme formal principle, most of his predecessors would postulate in addition other ultimate principles. In Plotinus everything derives from the One, even if the lower levels in the hierarchy function in fact as principles of multiplicity. In this sense Plotinus is an ardent monist.
The divine Intellect, the stage after the One, is also the realm of the (Platonic) Forms and of the real or primary being. The identification of the realm of the Forms with primary being is straightforward: by definition each Form is eminently and of itself that which it causes in others. But this primary being is also the universal Intellect: the Forms exist as the thoughts of Intellect, whose thinking of the Forms is described as self-thought, and its knowledge of them as a kind of self-knowledge (see especiallyV 5, V 8(31) and V 3). Of several arguments Plotinus advances for the claim that the Forms are internal to the Intellect, the philosophically most interesting one is an argument to the effect that if the Forms are outside the Intellect, its knowledge of them must be acquired; but the Forms are the standards of judgment and if the Intellect does not possess these standards previously it will lack the necessary means of recognizing the impression of each Form for what it is. So, if the Intellect does not essentially contain the Forms as its thoughts, its knowledge becomes problematic: an unacceptable conclusion since it is agreed that the universal divine Intellect has supreme knowledge. Plotinus' identification of primary being with a divine Intellect implies that there is a level of reality where knowledge and being, epistemology and ontology, coincide. This Plotinus takes to be a necessary condition of the possibility of knowledge.
As mentioned above, Intellect is characterized by a greater unity than the sensible world. This is first of all brought out by the fact that Intellect is non-spatial and non-temporal and hence free from the dispersion that has to do with space and time. Second, the part-whole relations in Intellect are such that not only does the whole, which is more than the sum of its parts, contain its parts, the whole is also implicit in each of the parts (see, for example, VI 2(43).20). Third, there is no real distinction between subject and attribute at the level of Intellect. Instead Plotinus posits intellectual substance and its activity (energeia), which is identical with the substance. Much of this doctrine about the relationships between items on the level of Intellect is founded on interpretations and suggestions in Plato's late dialogues. Plotinus takes the five 'greatest kinds' of the Sophist - being, sameness, difference, motion and rest - as the highest genera of his ontology. Each of these is distinct, but nevertheless presupposes and is interwoven with all the others. As a whole they constitute the Intellect or the intelligible substance. Particular Forms are generated from them.
The integrity of Intellect implies that Intellect's thought is different from ordinary discursive thought: Intellect grasps its objects and all their relations in an atemporal intuition of the whole, employing neither inferences nor words; the vehicles of its thought are the very things themselves, the prototypes and causes of which all other things, whether natural phenomena or lower modes of human thought, are inferior manifestations.
Soul is the level below Intellect. On account of the multiplicity of its functions, Soul is in some ways the most complex of the Plotinian hypostases and conceptually the least unified one. The historical sources of Plotinus' notion of Soul are primarily Plato's dialogues, above all the Timaeus, but Plotinus' psychology also reveals strong Aristotelian and Stoic influences.
Plotinus makes certain distinctions within the psychic realm. There is the hypostasis Soul, which remains in the intelligible realm, and there are the World-Soul and the souls of individuals, where the latter two are on the same level (IV 3(27).1-8). Within the two latter types of soul, Plotinus further distinguishes between a higher and a lower soul, corresponding to a distinction between soul which operates directly through a body and soul which does not (this distinction coincides with the distinction between rational and non-rational soul). Soul is the intelligible level which is responsible for the sensible world. The lower soul, sometimes referred to as nature (physis), produces matter itself, inorganic bodies and ordinary living things, including the sensible cosmos itself, which according Plotinus is a supreme organism (IV 4(28).33).
Plotinus holds that all souls are one, that all souls are identical with the hypostasis Soul (and by implication with one another). The Neoplatonists after Porphyry rejected this doctrine but Plotinus maintains it consistently and attaches considerable importance to it (IV 9(8); VI 4 (22).4; IV 3.1-8). Such a doctrine seems to be implied by the combination of two Plotinian doctrines that we have just mentioned: the Soul's membership of the intelligible realm (or the realm of real being) and the integrity of that realm.
It has been mentioned that Intellect is outside space and time. In On Eternity and Time, Plotinus states his views on time. The treatise contains interesting and powerful criticisms of the views of Aristotle, the Stoics and the Epicureans. As is often the case, Plotinus' own views are a development of Plato's Timaeus. He defines eternity as 'the life which belongs to that which exists and is in being, all together and full, completely without extension or interval' (III 7 (45). 3, 36-8) and time as 'the life of soul in the movement of passage from one mode of life to another' (III 7.11, 43-5). Thus, time comes in at the level of Soul as the 'image of eternity'. This means that Soul, in producing the sensible world, unfolds in successive stages what at the level above is present all together and without temporal interval.
Certain difficulties arise precisely on account of Soul's close relationship with the sensible. In the first place, how can Soul cause, administer and ensoul the extended sensible world without thereby coming to share in its extended nature? How can Soul operate in different parts of extension without being divisible into spatially distinct parts itself? If it is divided, its intelligible status will be lost or at least seriously threatened. This difficulty is increased by the fact that according to common and deeply ingrained opinion Soul is present in the bodies it ensouls. Plotinus was deeply disturbed by these and other puzzles having to do with Soul's relationship with the sensible realm as is demonstrated by the fact that he returns to the questions repeatedly. Despite brave attempts, it is questionable whether he succeeds in giving a satisfactory account of them.
One solution Plotinus frequently suggests and argues for, mainly from facts about the unity of consciousness in sensation, is that the Soul is present as a whole at every point of the body it ensouls. In this way it can be at different places without being divided. Its being present as a whole in different parts of space shows its different ontological status from that of bodies which have numerically distinct spatial parts (see, for example, IV 2 (4).2). Another account, however, presents Soul as not present in body at all, but rather the reverse - body as present in Soul. Body is in Soul in the same way that bodies may be said to be in light or in heat: they thereby become illuminated or warm without (in Plotinus' view) dividing or affecting the source of light or heat in any way. Similarly, bodies become ensouled, alive, by virtue of the presence of Soul. These ideas are explored in VI 4 (22) and 5 (23) (constituting a single treatise), which contain what is perhaps Plotinus' subtlest account of the relation between the sensible and the intelligible. Here he attempts to explain the apparent presence of the intelligible in the sensible in terms of its having effects in the sensible without being locally present there.
At the bottom of the Plotinian hierarchy lies matter. Plotinian matter is like the One in that it permits no positive characterization, but this is for exactly the opposite reasons. The One is, one might say, so full, so perfect, that it eludes any positive description. Matter, on the contrary, is such on account of its utter privation, or lack of being: it is sheer potentiality. Matter in Plotinus' system is the receptacle of immanent bodily forms, such as colours, shapes and sizes. Physical objects, bodies, are composites of matter and such immanent forms (VI 3(44).15). Matter itself is not subject to change but underlies change: as Forms come and go matter remains unaffected (III 6(26)). It is as such imperceptible, but reason convinces us of its existence as a purely negatively characterized substrate of forms. As what underlies the forms of bodies, it might be tempting to identify matter with space or with mass. Plotinus nevertheless rejects this, maintaining that the three-dimensionality of space presupposes local determination and that mass contains form, whereas matter is totally indeterminate and without form (II 4(12).8-12). Nevertheless, matter is the principle of spatial extension in that the dispersion characteristic of space is due to matter. Matter is an explanatory principle in the sense that it is necessary for explaining plurality, although it is not a principle of being in Plotinus' sense.
In the treatise I 8(51), Plotinus discusses at length questions concerning evil, a topic also brought up in many other treatises. The intelligible world is perfect and totally self-sufficient. While the sensible world is not, it is a reflection of the former and contains nothing which does not have its origins there. It is therefore puzzling how evil can arise. Plotinus argues that evil as such does exist and he identifies it with matter, understood as lack of all form, or non-being. This is absolute evil. Other things are evil in a relative way in so far as they have a share in matter.
In the preceding account of the Plotinian principles mention has been made of the relationships between the hypostases. It remains, however, to address this topic generally. Plotinus inherits from Plato two ways of describing the relationship: the language of participation and the language of model (paradeigma), imitation and image (eikon, eidolon). A lower level participates in a higher one, and thereby comes to have the character of the latter, or it imitates the higher to the same effect. Both these ways of describing the relation see it from the viewpoint of the effect. Plotinus and the other Neoplatonists have in addition ways of describing the relation in terms of the causal agency of the higher level. This is what is commonly called emanation, although Plotinus' language is quite varied here. He often simply uses expressions such as 'to make' (poiein) and 'to proceed' (proienai) for the activity of a higher realm. He also frequently uses the analogies of the sun and the light it radiates, fire and heat and the like, to illustrate how a higher hypostasis generates a lower, and occasionally he uses the metaphors originating in language about water (for example, 'to flow out'). He is well aware of the fact that these are metaphors that must not be understood too literally. The term 'emanation' may mislead in so far as it suggests that the cause spreads itself out. Plotinus, on the contrary, consistently maintains that the cause always remains unaffected and loses nothing by giving away.
In Plotinus there is sometimes an explicit and often an implicit distinction drawn between 'internal' and 'external activity' (energeia) (see, for example, V 3.12; V 4(7).2). This distinction runs through every Plotinian cause down to Soul and is crucial for an understanding of causation in the system. Keeping in mind what has been said about the identity of a substance with its activity, the internal activity will be the same as the thing itself. In terms of the light analogy the internal act is analogous to whatever the source of light, considered in itself and as a source of light, is doing. The external act is this same entity considered as operating in something else, causing the brightness on the wall for instance.
The matter is more complicated still: there is not only a process from the cause, but also a reversion (epistroph) of the produced towards its source without which the external act is incomplete. Since there is no pre-existent material principle, a recipient of form, what becomes informed must come from the informing cause. Thus, the outgoing aspect of a given level in the hierarchy functions as a material principle for the level below, the returning aspect as the informing of that material principle. Thus, reversion is equivalent to imitation. The product is an image or expression of the original, an effect, which nevertheless is not cut off from its cause, because the effect depends on the activity of the cause.
All activity except the internal activity of the One is a form of thinking or contemplation (theoria) (III 8(30)). (Even the One's activity appears to be mental activity of a sort, although it is not 'thinking' (see, for example, V 4(7).2; VI 8(39).16.) This holds even of the activity of the lower phase of the World Soul, nature, which creates the sensible forms in matter: all action (praxis) and production (poisis) have contemplation as their goal; production is the result of weak or imperfect thinking. We may visualize the system as a hierarchy where each stratum has an external activity, which in an attempt to grasp in thought its source creates an image of it, revealing it as more 'unfolded', less unified. So in a way the same items exist on every level: the One is everything there is, but in such a unified form that no distinctions are to be found. Likewise, Intellect and Soul, and finally the physical world contain everything there is. Only at the very lowest levels, that of matter and immanent sensible forms, is there no generation, which is another way of saying that we have reached the bottom.
Plotinus wrote some treatises on technical philosophical subjects such as potentiality and actuality (II 5(25)) and substance and quality (II 6(17)). The treatise on matter (II 4 (12)) may also be said to belong to this group. The most extensive among such treatises, however, is VI 1(42)-3(44), which Porphyry gave the title 'On the Kinds of Being'. In VI 1 Plotinus critically discusses Aristotle's Categories (see Aristotle §7; Categories §1), which he takes to be about the genera of being and, more briefly, the so-called Stoic categories (see Stoicism §6). He presents in VI 2 his own account of the genera of intelligible being, which for him is the only real being, and in VI 3 a revised version of Aristotle's categories doctrine is offered as an account to hold for sensible things. Plotinus' criticisms of Aristotle's category doctrine are founded on the assumption that it is about the genera of being. His main critical points are: (1) Aristotle's Categories fail to give a place to intelligible beings and hence cannot present a universal doctrine of the genera of being - it cannot be supposed to hold for both sensibles and intelligibles since there is no common genus for both and no discourse covering both at once; (2) each of the categories described by Aristotle fails to be one genus.
A noteworthy feature of Plotinus' psychology is his use of Aristotelian machinery to defend what is unmistakably Platonic dualism. For instance he uses the Aristotelian distinctions between rational, perceptive and vegetative soul much more than the tripartition of Plato's Republic (see Psych). He employs the Aristotelian notions of power (dynamis) and act (energeia), and sense perception is described very much in Aristotelian terms as the reception of the form (eidos) of the object perceived (see Aristotle §18). However, he never slavishly follows Aristotle and the reader should be prepared for some modifications even where Plotinus sounds most Aristotelian.
Plotinus identifies human beings with their higher soul, reason. The soul, being essentially a member of the intelligible realm, is distinct from the body and survives it. It has a counterpart in Intellect which Plotinus sometimes describes as the real human being and real self. As a result of communion with the body and through it with the sensible world, we may also identify ourselves with the body and the sensible. Thus, human beings stand on the border between two worlds, the sensible and the intelligible, and may incline towards and identify themselves with either one. For those who choose the intelligible life, philosophy (dialectic) is the tool of purification and ascent. As noted previously, however, it is possible to ascend beyond the level of philosophy and arrive at a mystical reunion with the source of all, the One. In contrast with the post-Porphyrian Neoplatonists, who maintained theurgy as an alternative, Plotinus stands firmly with classical Greek rationalism in holding that philosophical training and contemplation are the means by which we can ascend to the intelligible realm.
Plotinus' account of sense perception is an interesting example of how he can be original while relying on tradition. Sense perception is the soul's recognition of something in the external sensible world. The soul alone only knows intelligibles and not sensibles. If it is to come to know an external physical object it must somehow appropriate that object. On the other hand, action of a lower level on a higher is generally ruled out and a genuine affection of the soul is impossible because the soul is not subject to change. Plotinus proposes as a solution that what is affected from the outside is an ensouled sense organ, not the soul itself. The affection of the sense organ is not the perception itself however, but something like a mere preconceptual sensation. The perception properly speaking belongs to the soul. It is a judgment (krisis) or reception of the form of the external object without its matter. This judgment does not constitute a genuine change in the soul for it is an actualization of a power already present. In formulating this problem Plotinus' dualism becomes sharper, and in some respects closer to Cartesian dualism, than anything found in Plato or previous ancient thinkers. Plotinus contrasts sense perception as a form of cognition with Intellect's thought, which is the paradigm and source of all other forms of cognition. Sense perception is in fact a mode of thought but it is obscure. This is because the senses do not grasp the 'things themselves', the thoughts on the level of Intellect, but mere images. Since they are images they also fail to reveal the grounds of their being and necessary connections.
As the preceding account may suggest, Plotinus sees the goal of human life in the soul's liberation from the body and from concerns with the sensible realm and identification with the unchanging intelligible world. This is in outline the doctrine of Plato's middle dialogues. There are noteworthy elaborations, however. Plato holds that the soul's ability to know the Forms shows its kinship with them (Phaedo 79c-e). Plotinus agrees and presents a doctrine about the nature of this kinship which is left unclear in Plato. For as we have seen the whole realm of Forms is for Plotinus the thought of Intellect. The human soul has a counterpart in Intellect, a partial mind which in fact is the true self and is that on which the soul depends. This has two interesting consequences for the doctrine of spiritual ascent: (1) the soul's ascent may be correctly described as the search after oneself and, if successful, as true self-knowledge, as fully becoming what one essentially is; (2) on account of Plotinus' doctrine about the interconnectedness of Intellect as a whole, gaining this self-knowledge and self-identity would also involve gaining knowledge of the realm of Forms as a whole.
Plotinus' views on classical Greek ethical topics such as virtues (see Aret) and happiness (see Eudaimonia) are determined by his general position that intellectual life is the true life and proper goal of human beings. He devotes one treatise, I 2(19), to the virtues. The suggestion in Plato's Theaetetus (176a-b) that the virtues assimilate us with the divine is central to his views on them, and serves as his point of departure. The question arises how to reconcile this doctrine with the doctrine of the four cardinal virtues in the Republic. Plotinus distinguishes between political virtues, purgative virtues and the paradigms of the virtues at the level of Intellect. These form a hierarchy of virtues. The function of the political virtues (the lowest grade) is to give order to the desires. It is not clear, however, how these can be said to assimilate us to god (Intellect), for the divine does not have any desires that must be ordered and hence cannot possess the political virtues. Plotinus' answer is that although god does not possess the political virtues, there is something in god answering to them and from which they are derived. Furthermore, the similarity that holds between an image and the original is not reciprocal. Thus, the political virtues may be images of something belonging to the divine without the divine possessing the political virtues.
There are two treatises dealing with happiness or wellbeing: I 4(46) and I 5(36). In the former treatise Plotinus rests his own position on Platonic and Aristotelian doctrines, while criticizing the Epicureans and Stoics. He rejects the view that happiness consists at all in pleasure, a sensation of a particular sort: one can be happy without being aware of it. He also rejects the Stoic account of happiness as rational life. His own position is that happiness applies to life as such, not to a certain sort of life. There is a supremely perfect and self-sufficient life, that of the Intellect, upon which every other sort of life depends. Happiness pertains primarily to this perfect life that is in need of no external good. Since all other kinds of life are reflections of this one, all living beings are capable of at least a reflection of happiness according to the kind of life they have. Human beings are capable however of attaining the perfect kind of life, that of Intellect. In the latter treatise Plotinus holds with the Stoics that none of the so-called 'external evils' can deprive a happy person of their happiness and that none of the so-called 'goods' pertaining to the sensible world are necessary for human happiness (see Stoicism §§15-17). In I 5 he argues that the length of a person's life is not relevant to happiness. This is because happiness, consisting in a good life, is the life of Intellect and this life is not dispersed in time but is in eternity, which here means outside time.
Plotinus is one of the most influential of ancient philosophers. He shaped the outlook of the later pagan Neoplatonic tradition, including such thinkers as Porphyry and Proclus, and he left clear traces in Christian thinkers such as Gregory of Nyssa (see Patristic philosophy §5), Augustine and Boethius. Since all these were extremely influential in their own right, Plotinus has had great indirect impact. He clearly played a significant role in preparing for medieval philosophical theology. A forged extract from the Enneads was known in the Islamic world as the Theology of Aristotle. The supposed Aristotelian origin of this text helped the fusion of Aristotelianism and Neoplatonism that characterizes much of Arabic philosophy. Neoplatonism saw a revival in Europe during the Renaissance. A Latin translation of the Enneads by Marsilio Ficino first appeared in 1492 and gained wide distribution. Plotinus exerted considerable direct influence on many sixteenth-and seventeenth-century intellectuals. Even if the popularity of Neoplatonism and Plotinus receded in the seventeenth century, many individual thinkers since have read and been influenced by Plotinus, for instance Berkeley, Schelling and Bergson.
See also: NeoplatonismEYJÓLFUR KJALAR EMILSSON