Proclus differs first of all from Plotinus in not making Being his principle or purely abstract moment, but by beginning from unity, and for the first time understanding Being or subsistence as the third; thus to him everything has a much more concrete form. But the self-development of this unity is not made the necessity of the Notion with Proclus any more than with Plotinus; we must once for all give up seeking here for the Notion of disunion. Proclus (Theol. Plat. II. p. 95) says, “The one is in itself inexpressible and unknowable; but it is comprehended from its issuing forth and retiring into itself.” Proclus in the same place (pp. 107, 108) defines this self-differentiation, the first characteristic of unity, as a production (παράγειν), a going forth (πρόοδος), and also as a representation or demonstration. The relation to difference of the unity which brings forth is, however, not an issuing forth from self, for an issuing forth would be a change, and unity would be posited as no more self-identical. Hence through its bringing forth unity suffers no loss or diminution, for it is the thought that suffers no deterioration through the creation of a determinate thought, but remains the same, and also receives what is brought forth into itself.[249] As far as this goes, the Notion is, properly speaking, no clearer than with Plotinus.

What distinguishes Plotinus is his more profound study of the Platonic dialectic; in this way he occupies himself in his Platonic theology with the most acute and far-reaching dialectic of the One. It is necessary for him to demonstrate the many as one and the one as many, to show forth the forms which the One adopts. But it is a dialectic which to a greater or less extent is externally worked out, and which is most wearisome. But while with Plato these pure notions of unity, multiplicity, Being, &c., appear naturally, and so to speak devoid of other significance than that which they immediately possess (for we designate them as universal ideas which are present in our thought), with Proclus they have another and higher meaning; and hence it comes to pass that, as we have seen (pp. 59, 60), he found in the apparently negative result of the Platonic Parmenides the nature of absolute existence particularly and expressly recognized. Proclus now shows, according to the Platonic dialectic, how all determinations, and particularly that of multiplicity, are resolved into themselves and return into unity. What to the conceiving consciousness is one of its most important truths—that many substances exist, or that the many things, each of which is termed a one, and hence substance, exist in truth in themselves—is lost in this dialectic, and the result ensues that only unity is true existence, all other determinations are merely vanishing magnitudes, merely moments, and thus their Being is only an immediate thought. But since we now ascribe no substantiality, no proper Being to a thought, all such determinations are only moments of a thing in thought. The objection at this point made and constantly maintained against the Neo-Platonists and Proclus is this, that certainly for thought everything goes back within unity, but that this is a logical unity alone, a unity of thought and not of actuality, and that consequently there can be no arguing from the formal to actuality. From this they say it by no means follows that all actual things are not actual substances, that they have not different principles independent of one another, and even that they are not different substances, each of which is separated from the other and in and for itself. That is to say, this contradiction always begins the whole matter over again when it says of actuality that it is something implicit, for those who do this call actuality a thing, a substance, a one—which last are merely thoughts; in short they always again bring forward, as something implicitly existent, that whose disappearance or non-implicitude has been already demonstrated.

But in this regard Proclus displays great sagacity in a remark he makes on the manner in which this mode of production appears in the Parmenides of Plato, who shows in a negative way in this Dialogue that if the existence of unity is affirmed, the existence of multiplicity, &c., must be denied. Respecting these negations (ἀποφάσεις) Proclus now says (Theol. Plat. II. pp. 108, 109) that they do not signify an abrogation of the content (στερητικαὶ τῶν ὑποκειμένων) of which they are predicated, but are the creation of determinatives in accordance with their opposites (γεννητικαὶ τῶν οἷον ἀντικειμένων). “Thus if Plato shows that the first is not many, this has the significance that the many proceed from the first; if he shows that it is not a whole, it proves that the fact of being a whole proceeds from it. The mode (τρόπος) of negations is thus to be taken as perfection which remains in unity, issues forth from everything, and is in an inexpressible and ineffable preponderance of simplicity. On the other hand, God must likewise be derived from these negations; else there would be no Notion (λόγος) of them, and also no negation. The Notion of the inexpressible revolves round itself, never resting, and it strives with itself;” i.e. the one implies its determinations ideally, the whole is contained in the one. Multiplicity is not taken empirically and then merely abrogated; the negative, as dividing, producing, and active, not merely contains what is privative, but also affirmative determinations. In this way the Platonic dialectic wins for Proclus a positive significance; through dialectic he would lead all differences back to unity. With this dialectic of the one and many Proclus makes much ado, more especially in his famous elementary doctrines. The submersion of everything in unity remains, however, merely beyond this unity, instead of which this very negativity must really be grasped as signifying its production.

That which brings forth, according to Proclus, furthermore brings forth through a superfluity of power. There certainly also is a bringing forth through want; all need, all desire, for example, becomes cause through want; and its bringing forth is its satisfaction. The end here is incomplete, and the energy arises from the endeavour to complete itself, so that only in production the need becomes less, the desire ceases to be such, or its abstract Being-for-self disappears. Unity, on the other hand, goes forth out of itself through the superfluity of potentiality, and this superabundant potentiality is actuality generally: this reflection of Proclus is quite Aristotelian. Hence the coming forth of the unity consists in the fact that it multiplies itself, pure number comes forth; but this multiplication does not negate or diminish that first unity, but rather takes place in the method of unity (ἑνιαίως). The many partakes of the unity, but the unity does not partake of multiplicity.[250] The absolute unity which multiplies itself into many ones has consequently generated multiplicity as it is in these ones. Proclus makes use of a many-sided dialectic to show that the many does not exist in itself, is not the creator of the many, that everything goes back into unity, and thus unity is also the originator of the many. It is, however, not made clear how this is the negative relation of the one to itself; what we see is then a manifold dialectic, which merely passes backwards and forwards over the relationship of the one to the many.

To Proclus an important characteristic of this progression is the fact that it takes place through analogy, and what is dissimilar to the truth is the further removed from the same. The many partakes of unity, but it is in a measure likewise not one, but dissimilar to one. But since the many is also similar to what produces it, it likewise has unity as its essence; hence the many are independent unities (ἑνάδες). They contain the principle of unity within themselves, for if as being many they are likewise different, they are, so to speak, only many for a third, being in and for themselves unities. These unities again beget others which must, however, be less perfect, for the effect is not exactly like the cause, that which is brought forth is not quite similar to what brings it forth. These next unities are wholes, i.e., they are no longer real unities, unities in themselves, since in them the unity is only an accident. But because things themselves are in their synthetic nature merely wholes because their souls bind them together, they are dissimilar to the first unity, and cannot be immediately united to it. The abstractly conceived multiplicity is thus their mean; multiplicity is analogous to absolute unity, and is that which unites unity with the whole universe. Pure multiplicity makes the different elements like one another, and hence unites them to unity; but things only have similarity to unity. Thus things that are begotten ever remove themselves more and more from unity, and partake of it less and less.[251]

The further determination of the Idea is known as the trinity (τριάς). Of this Proclus (Theol. Plat. III. p. 140) first of all gives the abstract definition that its three forms are three gods, and now we have more especially to find out how he defined the trinity. This trinity is certainly interesting in the Neo-Platonists, but it is specially so in the case of Proclus, because he did not leave it in its abstract moments. For he again considers these three abstract determinations of the absolute, each on its own account, as a totality of triunity, whereby he obtains one real trinity. Thus in the whole there are three spheres, separated from one another, which constitute the totality, but in such a way that each has again to be considered as complete and concrete in itself; and this must be acknowledged as a perfectly correct point of view which has been reached. Because each of these differences in the Idea, as remaining in unity with itself, is really again the whole of these moments, there are different orders in production; and the whole is the process of the three totalities establishing themselves in one another as identical. It will be shown directly which orders these are, and Proclus occupies himself much with these, because he tries to demonstrate the different powers again in them. Proclus is hence much more detailed, and he went much further than did Plotinus; it may indeed be said that in this respect we find in him the most excellent and best that was formulated by any of the Neo-Platonists.

As regards the further details of his trinity there are, according to his account, three abstract moments present in it, which are worked out in his Platonic theology—the one, the infinite and the limitation; the last two we have likewise seen in Plato (p. 68). The first, God, is just the absolute unity already frequently discussed, which by itself is unknowable and undisclosed, because it is a mere abstraction; it can only be known that it is an abstraction, since it is not yet activity. This unity is the super-substantial (ὑπερούσιον), and in the second place its first production is the many ones (ἑνάδες) of things, pure numbers. In these we have the thinking principles of things, through which they partake of absolute unity; but each partakes of it only through a single individual unity, through the one, while souls do so through thought-out, universal unities. To this Proclus refers the forms of ancient mythology. That is to say, as he calls that first unity God, he calls these numerous unities of thought that flow from it, gods, but the following moments are likewise so called. He says, (Institut. theol. c. 162): “The gods are named in accordance with what depends upon the orders (τάξεων); hence it is possible to know from this their unknowable substances, which constitute their determinate nature. For everything divine is inexpressible on its own account and unknowable as forming part of the inexpressible one; but from differentiation, from change, it comes to pass that we know its characteristics. Thus there are gods capable of being known, which radiate true Being; hence true Being is the knowable divine, and the incommunicable is made manifest for the νοῦς.” But there always remains a compulsion to represent mythology in the determinateness of the Notion. These gods or unities do not correspond to the order of things in such a way that there are just as many and such unities (ἑνάδες) or gods as there are things; for these unities only unite things with the absolute unity. The third is just the limit which holds these unities (ἑνάδες) together, and constitutes their unity with the absolute unity; the limit asserts the unity of the many and the one.[252]

This is better expressed by what follows, in which Proclus takes up the three fundamental principles—the limit, the infinite and what is mingled—of Plato’s Philebus, because the opposition is thus more clearly determined; and therefore these appear to be the original gods. But to such abstractions the name gods is not applicable, for it is as returning that we first of all see them as divine. Proclus says (Theol. Plat. III. pp. 133-134): “From that first limit (πέρας),” the absolute one, “things have (ἐξέρτηται) union, entirety and community,” the principle of individuality, “and divine measure. All separation and fertility and what makes for multiplicity, on the contrary, rest on the first infinitude (ἄπειρον);” the infinite is thus quantity, the indeterminate, just as Plato in the Philebus calls the infinite the evil, and pleasure the untrue, because no reason is present in it (pp. 68, 69). “Hence when we speak of the process of anything divine, it is implied that in the individuals it remains steadfastly one, and only progresses towards infinitude,” continuity as self-production, “and has at the same time the one and multiplicity present in it—the former from the principle of limitation, and the latter from the principle of infinitude. In all opposition which is found in species that are divine, what is more excellent belongs to limitation, and what is less excellent to the infinite. From these two principles everything derives its progress until it steps forth into Being. Thus the eternal, in so far as it is measure as intellectual, partakes of limitation, but in so far as it is the cause of unceasing effort after Being, of infinitude. Thus the understanding in so far as it has the standard (ραραδειγματικὰ μέτρα) within it, is a product of limitation; in so far as it eternally produces everything, it has undiminished capacity for infinitude.” Multiplicity as Notion, not as the many, is itself unity; it is duality, or the determinateness which stands over against indeterminateness. Now according to Proclus (Theol. Plat. III. p. 137) the third is a whole, the unity of determinate and indeterminate, or that which is mingled (μικτόν). “This is first of all everything existent, a monad of many possibilities, a completed reality, a many in one (ἓν πολλά).” The expression “mingled” is not very suitable, is indeed faulty, because mixture at first expresses only an external union, while here the concrete, the unity of opposites, and even more the subjective, is properly speaking indicated.

Now if we consider further the nature of what is mingled we find the three triads likewise, for each of those three abstract principles is itself a similar complete triad, but under one or these particular forms. Proclus says (Theol. Plat. III. p. 135); “The first Being (τὸ πρώτως ὄν) is the mingled, the unity of the triad with itself; it is the Being of the life as well as of the understanding. The first of what is mingled is the first of all existence, the life and the spirit are the two other orders; everything is consequently in triads. These three triads determine themselves thus as absolute Being, life and spirit; and they are spiritual and to be grasped in thought.” According to this only the intelligible world is true for Proclus. But that Proclus did not make the understanding proceed immediately from the unity, is the second point in which he differs from Plotinus; in this Proclus is more logical, and he follows Plato more closely. His sequence is excellent, and he is right in placing the understanding, as the richer, last, since it is not until after the development of the moments which are present in life that the understanding springs forth, and from it in turn the soul.[253] Proclus says (Theol. Plat. I. pp. 21, 22, 28) that certainly in the first unity all agree, but that Plotinus makes the thinking nature appear just after the unity; yet the instructor of Proclus, who led him into all divine truth, limited better this indefinite way of looking at things adopted by the ancients, and differentiated this disorderly confusion of various orders into a comprehensible plan, and succeeded in satisfactorily following and maintaining the distinction of determinations. As a matter of fact we find more distinction and clearness in Proclus than in the turbidity of Plotinus; he is quite correct in recognizing the νοῦς as the third, for it is, that which turns back.

Regarding the relationship of the three orders Proclus now expresses himself in the passage already quoted (Theol. Plat. III. pp. 135-136) thus: “These three are themselves really contained in the existent, for in it is substance, life, the νοῦς and[254] what is the culminating point of all existence (ἀκρότης τῶν ὄντων),” the individuality of the self, the existent on its own account, the subjective, the point of negative unity. “The life that is grasped by thought is the very centre-point of existence. But the understanding is the limit of the existent, and it is thought as known (ὁ νοητὸς νοῦς), for in what is thought is thinking, and in thinking what is thought. But in what is thought thinking is in the mode of thought (νοητῶς), in thinking what is thought is in the mode of thinking (νοερῶς). Substance is the enduring element in existence and that which is interwoven with the first principles and which does not proceed from the one.” The second, “the life, is however that which proceeds from the principles and is born with infinite capacity;” it is itself the whole totality in the determination of infinitude, so that it is a concrete manifold. “The understanding is, again, the limit which leads back once more to the principles, brings about conformity with the principle, and accomplishes an intellectual circle. Now since it is a three-fold in itself, in part it is the substantial in itself, in part the living, in part the intellectual, but everything is substantially contained in it, and hence it is the foremost in existence, that which is united from the first principles.” That is the first reality. Excellent! “I call it substance, since the first substance (αὐτοουσία) is supreme over all existence and is, so to speak, the monad of everything. The understanding itself is that which knows, but life is thinking, and Being is just what is thought. Now if the whole of what exists is mingled, but the first existence (τὸ αὐτοόν) is substance, the substance that comes from the three principles (ὑφισταμένε) is mingled. What is mingled is thus substance as thought; it is from God, from whom also come the infinite and limitation. There are thus four moments, since what is mingled is the fourth.” The first is the monad, the absolute one, then come the many which themselves are units, the infinite of Plato; the third is limitation. The one is clearly all-penetrating, remaining at home with itself, all-embracing; it does not thus appear as one of the three moments, for Proclus adds a fourth which then likewise appears as the third moment, since it is the totality. “This united one is not only derived from those principles which are according to the one, but it also goes forth from them and is three-fold.” It is one trinity and three trinities. The limit and the infinite are, according to Proclus (Theol. Plat. III. pp. 138, 139), before substance and again in it; and this unity of moments is what comes first in all existence (πρωτίστη οὐσία). In the abstract trinity everything is thus contained in itself. Proclus says (Theol. Plat. III. pp. 139, 140): “The truly existent has the trinity of Beauty, Truth, and Symmetry in itself” (this is the way in which, like Plato, he names these three triads), “Beauty for order, Truth for purity, and Symmetry for the unity of what is joined together. Symmetry gives the cause that the existent is unity; Truth, that it is Being; Beauty, that it is thought.” Proclus shows that in each of the three triads, limit, the unlimited, and that which is mingled, are contained; each order is thus the same, but set forth in one of the three forms which constitute the first triad.