They will object that parts must necessarily fall under one ideal-form with their wholes. And they will adduce Plato as expressing their view where, in demonstrating that the All is ensouled, he says “As our body is a portion of the body of the All, so our soul is a portion of the soul of the All.” It is admitted on clear evidence that we are borne along by the Circuit of the All; we will be told that – taking character and destiny from it, strictly inbound with it – we must derive our souls, also, from what thus bears us up, and that as within ourselves every part absorbs from our soul so, analogically, we, standing as parts to the universe, absorb from the Soul of the All as parts of it. They will urge also that the dictum “The COLLECTIVE SOUL cares for all the unensouled,” carries the same implication and could be uttered only in the belief that nothing whatever of later origin stands outside the soul of the universe, the only soul there can be there to concern itself with the unensouled. Enneads IV,3,1
In a line, no doubt, the part is inevitably a line; but even here there is a necessary difference in size; and if, in the case of the soul we similarly called upon magnitude as the distinction between constituents and COLLECTIVE SOUL, then soul, thus classed by magnitude becomes quantitative, and is simply body. Enneads IV,3,2
But it is admitted that all souls are alike and are entireties; clearly, soul is not subject to part in the sense in which magnitudes are: our opponents themselves would not consent to the notion of the All-Soul being whittled down into fragments, yet this is what they would be doing, annulling the All-Soul – if any COLLECTIVE SOUL existed at all – making it a mere piece of terminology, thinking of it like wine separated into many portions, each portion, in its jar, being described as a portion of the total thing, wine. Enneads IV,3,2
Now as in soul unity does not debar variety, so with Being and the Beings; in that order multiplicity does not conflict with unity. Multiplicity. This is not due to the need of flooding the universe with life; nor is the extension of the corporeal the cause of the multiplicity of souls; before body existed, soul was one and many; the many souls fore-existed in the All not potentially but each effectively; that one COLLECTIVE SOUL is no bar to the variety; the variety does not abrogate the unity; the souls are apart without partition, present each to all as never having been set in opposition; they are no more hedged off by boundaries than are the multiple items of knowledge in one mind; the one<one soul so exists as to include all souls; the nature of such a principle must be utterly free of boundary. Enneads VI,4,4
Besides, the soul, even the COLLECTIVE SOUL for all its absence of part, is a manifold: it has diverse powers – reasoning, desiring, perceiving – all held together by this chain of unity. Itself a unity, soul confers unity, but also accepts it. Enneads VI,9,1