This vision of the universe of Plotinus

The vision of the universe of Plotinus is not unique; we saw it sketched out in Posidonius when he distinguished and ordered what ancient Stoicism identified as god, destiny, and nature; we saw it clarified in Plotinus with his theory of the triple unity. What is its principle? We have seen the Stoics (and Plotinus formally adopts this) maintain that the degree of reality of a being depends on the degree of union of its parts, from a pile of stones with merely juxtaposed parts, to a living being whose parts are all held together by the tension of the soul, passing through a collective body, such as a choir or an army. We can conceive of union increasing to the point where the parts merge and become increasingly inseparable: thus, we cannot speak in the same sense of the parts of a living body and the parts of a science; in a living body, the parts are interdependent, but locally separate; in a science, a part is a theorem, and each theorem contains potentially all the others; we thus see how a further degree of unification leads us from the corporeal to the spiritual.

But every reality in which the union of parts is not perfect presupposes above it a more complete unity; thus, the mutual sympathy of the parts of a living body or of parts of the world presupposes above it a more perfect unity, that of the soul, which contains them; the union of the theorems of a science presupposes the unity of an intelligence that grasps them. Without this higher unity, everything scatters, crumbles, and loses its being. Nothing exists except through the One; Aristotle was wrong to say that being and the One are always convertible: in reality, being is always subordinate to the One; the One is the principle of being. But on one condition: that this unity is not a purely formal and empty unity but contain all the reality that will develop in its product: the soul of a living being contains within itself, in the state of seminal reasons inseparable from one another, all the details of the living body; nothing real that does not come from it. On this condition, we see the scope of the mode of intelligibility employed by Plotinus, which consists in making any reality understood by relating it to a more perfect unity[1].

Yet Plotinus entirely abandons the Stoic theory, whose formulas he sometimes used; For the Stoics, as we recall, unification was due to an activity inherent in the agent, which penetrated matter and, through its tension, held its parts together. For Plotinus, all unity is always more or less of the kind found in a science; in a science, the mind is one because it contemplates one and the same object; what introduces unity into lower reality is the contemplation of the higher principle[2]. To say that the one is the principle of being is thus tantamount to saying that the only true reality is contemplation. Not only is intelligence contemplation of its object, but nature is also contemplation—tacit, silent, unconscious contemplation—of the intelligible model it strives to imitate; an animal, a plant, any object whatsoever has its form (in the Aristotelian sense) only insofar as it contemplates the ideal model reflected in it. The supreme principle thus remains in itself, in its unalterable perfection and immobility; nothing of itself, of its activity, passes into lower reality, since, like beautiful things, it only fills things with its light and reflection to the extent that they can receive it.

However, to grasp it fully, one must have in mind the fixed image of a single, finite, and eternal cosmos, with its order always identical to itself, which obsesses the mind of Plotinus as it does that of all his contemporaries; it is in relation to this image that his metaphysical doctrine takes on meaning. The given is the unity of the sensible world, and all the intelligible realities on which it depends are but this same world, more contracted and, in a way, dematerialized. The entire metaphysical construction of Plotinus loses much of its meaning if one does not accept, along with the uniqueness of the world, its unity, the sympathy of its parts, its eternity and geocentrism[3].