Plotinus on the Individuation of Souls

In Ennead IV Plotinus discusses the individuality of human souls and their relation to the Soul of the All and the hypostasis Soul. This topic is a product of — and only intelligible concerning — Plotinus’s wider philosophical scheme. Ultimately, Plotinus wants to maintain two seemingly contradictory theses. On the one hand, he holds that the soul of Socrates, for instance, really is an individual apart from the hypostasis Soul. On the other, he also claims that individual souls are in some way one with the hypostasis Soul. In this paper, I will show how Plotinus attempts to reconcile these positions. In so doing I will first consider what Plotinus says about the nature of souls, and then their relationships with one another as well as their bodies. Finally, I will show how individual souls retain their individuality in light of these considerations.

What, then, does Plotinus take a soul to be? While specifics will differ depending on what kind of soul one has in mind, there are commonalities. Plotinus discusses the essence of the soul in Ennead IV 1 and Ennead IV 2. He first observes that the soul is an intelligible, rather than corporeal, being (IV. 1 [4] 1, 5). Plotinus then makes the distinction between two kinds of divisibility. First is primary divisibility, pertaining to corporeal bodies, which Plotinus describes as follows:

These are the perceptible sizes and masses, which each have their own place, and it is not possible for the same one to be in several places at once. (IV. 1 [4] 1, 15)

To illustrate, consider a plain white wall. While the whiteness on two different parts of the wall is qualitatively identical, they are not numerically the same whiteness. This is not the case with something that is divisible into bodies. Here a form is wholly present in each part of the body it informs (IV. 1 [4] 1, 25). It is this kind of divisibility that souls have. But the soul, like all intelligible realities, is also one and unified (IV. 2 [21] 1, 10). Thus, Plotinus concludes that it is simultaneously divisible and indivisible, albeit not in the same respect (IV. 2 [21] 1, 15). Plotinus also holds that the soul is that which gives form of the body (IV. 3 [27] 20, 40). That is to say, the soul is the principle of the body’s unity, existence, and intelligible structure. This does not mean, however, that the soul depends on the body in any way. Rather, the soul is an independently existing substance (IV. 1 [4] 1, 5).

With this in mind, we can now consider three different types of souls in Plotinus’s universe. First are the souls of individual human beings. This kind of soul is the most self-explanatory. Such a soul is united to a particular body and is the principle of the unity of said body (IV. 3 [27] 6, 15). So, for example, the soul of Socrates is the form of Socrates’s body and no other. However, Plotinus is clear that it is not the entire soul which is present to the body. Plotinus distinguishes between the higher soul and the lower soul. The lower soul is immanent in the body, operating in and through it (IV. 2 [21] 1, 10). On the other hand, the higher soul is transcendent of the body (IV. 2 [21] 1, 10). To be clear, the higher and lower souls are not two numerically distinct souls, but two parts of a single soul.

Plotinus also argues for the existence of the soul of the All. The soul of the All is to the entire corporeal cosmos what the soul of Socrates is to Socrates’s body. The soul of All is present in the cosmos but transcendent of it (IV. 3 [27] 6, 25). It is the form of the entire cosmos, meaning that it is the principle of its unity, existence, and structure. This is unproblematic in the case of inanimate things that have no individual souls, but living things are also a part of the cosmos. This means that, for Plotinus, the body of Socrates has in it both his individual soul and the soul of All. To explain this, Plotinus would either have to consider individual souls as mere parts of the Soul of the All, or accept that a body can have multiple substantial forms to account for the overlap. We shall see later that Plotinus does not accept the former option, so he is compelled to accept the possibility of multiple substantial forms overlapping in a single body (IV. 3 [27] 8, 55).

As I noted above, Plotinus wants to maintain that individual souls and the soul of the All are in different respects one with and distinct from the hypostasis Soul. His position on this is multifaceted, and I will begin with the fact that he argues that these souls come from a common source:

This assertion that all souls are one thing has many difficulties; unless of course one made the one stand by itself without falling into body, and then said that all the souls, the Soul of the All and the others, came from that one, living together with each other, so to speak, down to a certain level and being one soul by belonging to no particular thing. (IV. 3 [27] 4, 15)

This principle from which individual souls and the Soul of All come is the soul as a whole (which I have been calling the hypostasis Soul). Moreover, the soul of the All and individual souls are parts of this hypostasis soul. (IV. 3 [27] 4, 10) Therefore the Soul of the All and individual souls are one inasmuch as they are parts of this whole. The question, then, is how Plotinus understands their status as parts.

Plotinus compares the matter to the Intellect. In the Intellect, all of the ideas constitute a unity and are thereby one and indivisible (IV. 4 [28] 1, 20). Yet they are also divisible in the sense that the objects of the intellect are still manifold. In other words, as Plotinus explains, the Intellect is one and many in that it knows all of its objects (the forms or ideas) in a single, simple intuition (IV. 4 [28] 1, 20). There is also a second sense in which the intellect is divisible. For while the forms are all united in the intelligible realm, they are separated and divided here on earth.

With this in mind, we may return to the above quote and see in what sense the Soul of the All and the souls of individuals are parts of the hypostasis Soul. Now, as is most clear when the quote is taken in context, to say that these souls are one and many in the way that the Intellect is only works if the hypostasis soul remains in the intelligible realm while the souls it produces descend into bodies (IV. 3 [27] 4, 10). This illustrates the first sense in which souls are one and many: just as the forms are one in the Intellect, but separable in the corporeal realm, so too are the souls many by being divisible into bodies. The hypostasis Soul remains totally undescended, the Soul of the All descends into bodies but not as much as the souls of individuals do (IV. 3 [27] 4, 20). However, this explanation is so far incomplete for two reasons. Firstly, it only accounts for the individuality of the lower parts of souls. But Plotinus is not content to say that one with respect to their higher part and many with respect to their lower part (IV. 3 [27] 5, 5). This is especially problematic because the souls of individual human beings will eventually, upon death, be without bodies. Ergo, if their higher soul is absolutely one with the hypostasis Soul, they will cease to be upon death by disappearing into it (IV. 3 [27] 5, 5). Therefore, he must give an account of how these souls retain their individuality in the intelligible realm. To address this problem, Plotinus again makes a comparison to the Intellect:

So we have given the sum of the discussion, that the souls spring from one, and the souls springing from one are many in the same way as Intellect, divided and not divided; and the soul which abides is a single expression of Intellect, and from it spring partial expressions which are also immaterial, just as in the world of Intellect. (IV. 3 [27] 5, 15)

The first thing to note is that Plotinus is undoubtedly thinking of the higher soul here, not the lower. This is obvious from the fact that he describes the souls that spring forth from the hypostasis Soul (here called the soul which abides) as immaterial without the added qualification that they are divided into bodies. Even more compelling is the context of the quote. As I noted above, Plotinus is specifically dealing with how higher souls retain their individuality in this chapter, and this quote is explicitly a summary of his position on the matter. Next, as Plotinus explains, there is not just one Intellect, but also many lesser intellects which are partial expressions of Intellect. Likewise, there is not just one Soul, but also many lesser souls which are expressions of it. The fact that Plotinus speaks of these lesser intellects as springing forth also shows that Intellect — like the hypostasis Soul — somehow produces its pale copies.

This quote also reveals that the hypostasis Soul, like the lesser intellects, is an expression of Intellect. This matters because Plotinus claims that lesser souls have the same relationship with lower intellects that the hypostasis Soul has with Intellect itself (IV. 3 [27] 5, 10). That is to say, they are expressions of these lesser intellects, with each soul corresponding to its own intellect:

So too it is with souls, which depend in order on each several intellect, and are expressions of intellects, further unfolded than they are, having passed, we may say, from brevity to multiplicity. (IV. 3 [27] 5, 10)

This is the core of Plotinus’s solution to the difficulty. The above quote is quite unambiguous about this; the multiplicity of souls is accounted for by the fact that each corresponds to its own intellect. But how are we to understand these lesser intellects? I argue that they are best understood as something like forms of individuals. This is because A) there is a more or less one-to-one correspondence between souls and intellects and B) each soul is an expression of its corresponding intellect. I say ‘like forms of individuals’ because Plotinus does not specify whether they are formal causes or not, though they are at least analogous.

Secondly, Plotinus still needs to account for how all souls are one in the intelligible realm. Not only that, but he must also account for how this oneness is reconcilable with the multiplicity of souls as I have just described it. Unfortunately, Plotinus does not devote a chapter to explaining this matter, as he does with others. However, he still says enough to make his position clear. Throughout Ennead IV, Plotinus repeatedly remarks that, like Intellect and its partial expressions, all souls share a single form. I contend that this is the sense in which souls are one at the intelligible level. That this is Plotinus’ position is most evident when he writes the following:

So all [both individual souls and the soul of the universe] will be parts of one, since they have the same form. (IV. 3 [27] 2, 55)

Plotinus could hardly be more clear; individual souls and the soul of the All are one — that is, they are parts of a whole — because they have the same form. Moreover, as I have explained above, this whole is the hypostasis Soul. It also coheres with Plotinus’s wider picture of the universe. If the partial intellects are expressions of Intellect, and individual souls are expressions of the partial intellects, then it seems that all souls are — directly or indirectly — expressions of Intellect. As such, one should expect them to be one in form. As for the nature of this parthood, Plotinus compares it to the relationship between a theorem and the science to which it belongs (IV. 3 [27] 2, 50). The theorems that compose a science each contain the whole science potentially without detracting from the unity of the science (IV. 3 [27] 2, 50). While he does not go into detail about how theorems contain their science potentially, this model does map onto his account of souls perfectly and resolves a potential difficulty with it. For one might ask how souls which are of the same form can differ so radically. We have indeed accounted for their numerical individuation, but this alone is insufficient to explain the qualitative differences between the soul of the All and the soul of Socrates. But if we consider the fact that each soul contains the whole potentially, just as a theorem contains its science, this difficulty is dissolved. The differences between souls are only differences in actuality. That is, they differ in what aspects of the same form they express through their activity. Plotinus himself seems to say as much, writing:

Is it a part in the way in which a theorem that belongs to a science is said to be part of the whole science, which continues to exist [as a whole] none the less, and its division is a kind of manifestation and activity of each individual part? (IV. 3 [27] 2, 50)

Again, this lines up well with the rest of his account. The soul of Socrates is an expression of a partial intellect. As the term “partial” implies, this intellect is itself a partial expression of Intellect. Given that souls are one and many in the same way as intellects, one may infer that partial intellects bear the same relation to Intellect as a theorem to its science. For this reason, I take Plotinus to hold that the soul of Socrates, for instance, partially expresses its form in its particular way because the intellect to which it looks is a similarly partial expression of Intellect.

Finally, there is a third similarity between the relationship between a theorem and its science and a soul with the hypostasis Soul. Namely, Plotinus claims that a science is not a mere aggregate of theorems, though it is related to them as whole to parts, but an independently existing thing (IV. 3 [27] 2, 55). In like manner, hypostasis Soul is spoken of as existing in its own right.

To summarize, then, Plotinus holds that souls are both one and many at the intelligible level. They are one in form, and each soul is part of the hypostasis Soul just as a theorem is related to a science. Yet they are also many in that virtue of the fact that they are expressions of different intellects. In turn, their lower parts are also many by how they become divided into bodies. Moreover, despite overlap, the souls of individuals are distinct from the soul of the All. Finally, their being one and many at the intelligible level is reconciled by Plotinus by the aforementioned comparison of their parthood to a science and its theorems.