citizenzen, might I recommend an investigation of the Biblical phrase: "Book of God's Remembrance?" I think you'll find some of what you're looking for there, although Nick has already spoken to this same teaching ... as it exists in the Vedas [Akasha being Sanskrit].
Our higher selves, by the way, are not quite identical to the incarnate soul ... or that which is sent forth to experience life in the the three worlds [physical, astral, mental]. From the plane of higher mind, the Soul is regarded as a watcher, meditating on `its reflection' ... yet even while out of incarnation, when we "re-join" this aspect of our being, we nevertheless remain distinct individuals.
The idea, in short, is that our Soul once was a member of the human Kingdom, just as ourselves. Long ago, in a prior cycle of evolution, the Manasaputra [Son of Mind] attained to its own freedom, and hence it does not literally reincarnate, or project itself into the three lower worlds as we do. Rather, the Soul is incarnate on a `higher turn of the spiral,' and the densest plane of incarnation for it is the Higher Mental.
So, we have the relationship to the Soul of something like student to Teacher, although we also maintain our own vehicles of consciousness [formless, therefore not `bodies' as such, yet definitely a temporary means of expression for our Higher Principles] in the world of Higher Mind, and beyond. The Soul can be regarded as One which is nearly Perfect, in the same ways which we are currently striving to emulate ... with such figures as a Buddha, a Christ, a Master or an Arhat as demonstrating precisely what this Perfection looks like while yet we still remain in incarnation.
Any farther progression than a Buddha will remove us from this realm altogether, and although we continue our spiritual evolution elsewhere, we are no longer able to incarnate in the lower worlds at all. Because the Kingdoms overlap, however, a Master, a Buddha or a Christ is actually quite more advanced than our own Manasaputra [Soul] ... and therefore it is an entire study, unto itself, as to which `Soul Grouping' we find ourselves belonging to within the current Human Family, and what this will then entail.
Karma applies to Groups in addition to individuals, as also to the whole of Humanity, to other Kingdoms both sub- and super- ... and even to "the ONE in Whom we live, and move, and have our Being." Gods, too, incarnate ... and these are the Prajapatis, the Solar and Planetary Logoi, our sister and parent Suns, etc. We exist, only because They exist; what they are in Macrocosm, we are in microcosm. Big picture, little picture, etc.