After The Laws of Procession, this is the second subsection of Dodds' section titled "Of Procession and Reversion." Last time we talked about where every thing comes from, and now we're talking about where every thing goes.
The Cycle of Procession and Return: In the same way that every cause produces things as similar as possible to itself, every effect is drawn towards and returns to its cause by identifying with it. This cycle of procession and return is not two distinct motions, but merely two ways of looking at the same eternal, continuous process.
XXXI. Every thing that proceeds from a cause returns to it.
Every thing that proceeds from a cause depends on it and participates in the Good through it [IX]. This means that a cause is good to its effects. Every thing that exists desires its good [VII], and desire prompts motion: so every thing that proceeds from a cause desires its cause and moves towards it.
XXXII. All return is effected through similitude of effect and cause.
Things are united by similitude and separated by difference. So when a thing attempts to return to its cause, it attempts to unify with it, and therefore attempts to be as similar to it as is possible.
XXXIII. Every thing that proceeds from a cause and returns to it acts cyclically.
If every thing that proceeds from a cause returns to it [XXXI], then its beginning and end are one and the same, and thus its action is a cycle. Some things make small cycles from and to their immediate prior, while others make large cycles from its ultimate cause; but all are cyclic.
XXXIV. Every thing that is capable of return will return to its cause.
Because return is effected through similitude [XXXII], a thing that can return will be similar to the thing returned to. There are three ways that two things can be similar: they can be identical, they can both have a shared cause, or one can be the cause of the other. If they're identical, they are already one thing and so already returned. If they have a shared cause, then we can repeat this analysis between the cause and each effect. If one causes the other, then the effect will return to its cause [XXXI]. So every thing returns its cause.
The One is the cause of everything [XII, XIII], but transcends existence [VIII]; the highest cause that exists is therefore intellect [XX]. Therefore it is apparent that every thing capable of return will ultimately return to intellect.
XXXV. Every thing remains in, proceeds from, and returns to its cause.
We have already established that every thing both remains in and proceeds from its cause [XXX] and that every thing that proceeds also returns to its cause [XXXI]; so every thing must simultaneously remain in, proceed from, and return to its cause.
This is where Proclus' mention of "return" way back in XV through XVII finally comes into proper discussion: recall that souls are that which are that which are capable of returning to themselves. Pseudo-Iamblichus notes in The Theology of Arithmetic that the number one (that is, the One) is the source of identity (that is, remaining), that the number two (that is, the Intellect) is the source of difference (that is, procession), and that the number three (that is, souls) are the source of harmonization (that is, return), which is another way of looking at what Proclus is talking about here.
It is important to note (and Taylor—bless him—is unable to help himself and does in his usual grandiose style) that both procession and return, despite being cyclic, do not occur in sequence or in time: they happen simultaneously and eternally. So when Proclus notes that every thing returns to intellect in XXXIV, this doesn't mean the material universe has a beginning or an end, but rather that it's in a constant state of continuous unfolding. Dodds notes that Proclus never formally states or proves the eternity of the world in the Elements; but since Plotinus and Sallustius made such a big deal of it a hundred years prior, I wonder if the Christians stopped trying to hasten the apocalypse in the intervening interval?
Speaking of which, Proclus' corollary at the end of XXXIV is a little bizarre. Firstly, he has not established that intellect is a unique thing, just that there is an intellectual nature above the soul. Second, he never established that its the first existent but assumes it without proof! I have attempted to supply the gap myself, but it strikes me as a significant omission.
I recommend reading XXXV in the original: Proclus gets really cute and considers every possible binary case of a thing remaining in, proceeding from, and returning to its cause, with a very brief proof of the impossibility of all but the desired case. The result is a nice summary of XXV through XXXIV. I have greatly truncated it since the logic follows that previously established.
Of this section generally, Johnson cryptically notes that "there are three primary forms of return, viz. through essence, through life, through knowledge." I am not sure what he's referencing here (unless he is obliquely referencing the One, the Intellect, and Soul), as I haven't seen these three paths discussed elsewhere in Platonic sources, but it sounds remarkably reminiscent of the three yogas mentioned in the Bhagavad Gita or the three paths up from Malkuth in the Tree of Life. Possibly it's from later in the Elements?
The triad of imminence, procession, and return between levels of existence is, of course, Plotinus' whole thing; Dodds notes that Iamblichus and Proclus consider it to be true within a level of reality, too—that is, souls also reside in, proceed from, and return to their prior souls. This is something I've been thinking about a lot, since I personally try to keep myself intently fixed on my angel, which the Neoplatonists (and I) would consider my immediate prior; this is something that obviously seems good to me, and is bearing good fruits, but Plotinus (being obsessed with love for the One) didn't discuss it and the Christians (similarly obsessed, but with a different "one") would consider it somewhere between misguided idolatry and outright blasphemy. But it seems to me that the direction one's looking is what's important: are you looking up or looking down? As long as you're looking up, does it really matter too much if you're looking at something close or far away? Anyway, it's nice to see prior authority for something I've been considering on my own.