§4.2.1. It is in the intelligible cosmos that true Substantiality is to be found. Intellect is the best part of it. Souls are also in the intelligible world; for it is from there that they come to be in the sensible world, too.1 And that cosmos contains souls without bodies, whereas this one contains those which have come to be in bodies and are divided among them. In the intelligible world, Intellect is all together and [its contents 5are] not separated or divided, and all souls are together in a world of eternity, not one of spatial extension.
Intellect, then, is always without separation and is indivisible, and Soul in the intelligible world is without separation and undivided; it has, though, a natural propensity to be divided. For its propensity to division involves its departure from that world and its coming to be in body. So, 10then, it is plausibly said to be ‘divided among bodies’,2 because it departs in this way and is subject to division.
How, then, is it also undivided? The reason is that it does not totally depart, but there is an element of it that has not gone forth, whose nature it is not to be divided. The phrase, then, ‘from the indivisible and ever-unchanging [Substantiality] and from the divisible [substantiality] which comes to be in bodies’ is identical to saying 15that the soul is composed of that which exists above3 and that which depends upon the intelligible world, but has flowed forth as far as the sensible world, like a line from a centre. But having come to the sensible world with this part, observe how4 with this very part it preserves the nature of the whole. Not even in the sensible world, after all, is it solely divided, but it is also undivided; for that in it which is divided is divided indivisibly.5 In giving itself to the whole body, it is 20divided even while not being divided, by being whole in all the parts of the body.