Souls And Stars

One of the core tenets of this theory is that the soul, whether divine or mortal, consists of multiple parts. Personally, I prefer two: AE and Animus. They interact to produce what is perceived as the embodied self, but they can be separated, and to some extent substituted with alternates.

AE

AE is the self. It is who you are, what you are, where you've been and what you've done, what you're doing, what you plan on doing. It is the mind and the history of that mind. It is the spirit. The ghost. The story and song.

That part is pretty straightforward.

Animus

The animus is the motive force, that which the AE directs to form a body and take actions in a material sense. It is the energy of life, and, for divine beings, it is their Heart, their divinity.

For some time I've been kind of muddled about what exactly the animus is in my model. Now, though, I'm fairly confident: The animus is a star. Each and every animus, from a skeever's on up to a Prince's.

A star, in the Aurbis at least, is a hole punctured through spacetime to Aetherius, the realm of unending creatia. Creatia, also known in some forms as magicka, is the raw substance of possibility, and it is shaped by AE into specific forms. The stars we usually think of are arranged around Mundus in the three (or higher) dimensional space of Oblivion, torn by the Magna-Ge as they fled Mundus, but the stars I'm talking about here are inside mortal bodies, too small and faint to be seen; if I had to place them in a specific organ, I would say either the heart or the brain.

A skeever's star is tiny, absolutely miniscule; it lets through only enough creatia to move an extant body. It's not enough to create a realm, or create a body all at once, or even cast spells. It can only animate what the skeever has to work with, and that body, though also made of creatia, has to be formed and maintained by external sources of magicka/creatia, in the form of food and water.

Sapient mortals are in much the same boat. Their animating star is too small for them to form new bodies when separated from the one they are born into. However, they do have enough to work with to build up a surplus reserve within their bodies, and that is what gets used for the casting of spells. (Note that this reserve's size has little to do with the physical size of the body. More on this in a bit.)

Spirits regarded as gods, on the other hand, tend to have gigantic stars. They form the enormous amounts of creatia pouring out of these stars into realms and bodies and effects of unfathomable complexity and potency. This is the state of a Prince, or an Aedroth, in terms of animi.

(Im)mortality and the Origin of a Star

What, then, causes this difference in size? Why are the mortals consigned to work with piddling, barely sufficient streams of creatia when the Princes enjoy torrents?

Consider how, exactly, an Aurbical star is formed in the first place. It is torn by an AE. It is ripped open by force. The thing that determines the size of the animus is the AE, the spirit doing the tearing of spacetime to make the star.

A mortal AE has its mortality written into its story-self. Such an AE lacks the ability to keep a star open as widely as a Prince, but also, and this is key, for as long as a Prince can. The mortal AE, unless reshaped by some process like the Walking Ways, simply doesn't have the capacity to maintain a star indefinitely or of godlike size.

This is not to say that the size of an animating star is fixed. Far from it. Even in the course of a normal mortal's life, it can fluctuate, based on experience, practice, fluke, personality, etc. Further, a mortal's ability to hold on to un-formed creatia (that is, a magicka pool for spellcasting) likewise can fluctuate. And, eventually, all mortal stars close up, because the story keeping them open has ended.

The immortal spirits known as gods, however, can keep their stars open indefinitely (this is immortality) and at monstrously large sizes (this is godhood, or rather, a state that tends to prompt the labeling of a spirit as a god). They often use this creatia to form realms around their stars and bodies to manipulate (though these are not the same thing). Further, compared with each other they may have significant differences in power, both influx and stored, but throw in a regular mortal and it's like weighing the difference between a feather, ten tons of bricks, and eleven tons of bricks. One of these is not like the others. However, that mortal may well attempt to transform itself into a comparable entity, and succeed, which is the essence of the Walking Ways.

Enchanting

Enchanting, then, is largely a matter of capturing an animating star before it closes up in the absence of its AE, and then attaching that star to an object with instructions to produce an effect (a spell).

The process of capturing a star has two major variations. You can capture the AE with the star and shackle them together (necromancy, bad when subject unwilling or unable to consent, but more potent than other options for enchanting), a process which requires black gems for sapient creatures because of Arkay's intervention. The extra potency here (and thus the desirability) comes from the ability to extend the life of the star by forcing the AE to keep it open longer than it usually would be. (This difference isn't necessarily reflected in game mechanics.)

Alternatively, and as is the practice with most enchanting for ethical and practical reasons alike, you can capture just the star and encase it in a normal gem, letting the AE go. This results in an enchantment that must be recharged sooner than one the necromantic process would result in. It's like two kinds of batteries: One lasts longer than the other, but the one that lasts longer is made with horrible and unethical practices.

Charging an enchantment would then consist of plugging in a new star in the wake of or alongside a fading one. I like to imagine that soul gems are able to keep a star open indefinitely for storage purposes, but are ill-suited to emitting effects due to the same property that allows them to keep the star open in the first place.

(Of course, necromancers can have other reasons to capture souls than just enchanting, so they may not even care about potency for enchanting.)

Lunar Currency

Death results in reappropriation of spirit towards its aligned AE—either to the god-planet Aedra or the Principalities of Oblivion. Vehk’s name for this transaction, mentioned above, is “lunar currency”.

Lunar Currency is the trade of souls. Some spirits hoard weaker spirits in their realms, especially dead mortals, in order to accrue power and gain advantage over each other or in some other project. Perhaps after death, an AE gains the ability to tear a new star, probably smaller, but longer lasting or maybe even eternal. (Consider what happens after most real-world super novae!) It would make sense, then, for gods to hoard such spirits: Too weak to escape even if they want to, and they constantly pump creatia from Aetherius into the realm of the god that has them, adding to their stores.

This would conflict with the enchanting section above, unless these AE can only form such stars once they've left the Mundus: Their mortal stories are done, but their afterlife epilogues have a long way to go. They exist in a different way than they did as living mortals, so of course any new stars they form might also be different.

Lorkhan

Lorkhan was a god, so why did taking away his star prevent him from forming a new, identical one? Precisely because Lorkhan was a god. His AE was altered in the same moment his star was cut out of him; the blade cut the Heart out as well as his ability to form that Heart. And, this is key, Nirn's AE was altered as well. Convention was a Heart Transplant, whether accidental or planned. Lorkhan's original star was kept open by the machinery of Nirn, which claimed that divinity as its own. Lorkhan has to find a new one (and he does) because if he tries to take his old one back, he'd rob his beloved Nirn of its divinity.

Constellations

Now I turn to the more well-known stars of the Aurbis, the ones torn by the Magna-Ge. These stars are interesting, because the spirits that made them are on the other side of the holes when compared with the animating stars. They don't need access to creatia in order to animate anything; they're already within the source of all creatia.

This means they have some other motive for keeping those holes open. Personally, I think it's because they don't want to lose the ability to look back at Mundus, out of a mixture of survivor's guilt, hope, regret, and a desire to keep the door open for less powerful AE to escape. And Magnus in particular records the history of Mundus with the Scrolls.

Interestingly, this could afford them the ability to shape creatia as it pours out of Aetherius, causing effects in Oblivion and Mundus. I imagine this allows them to shape events in broad, subtle strokes.

I also imagine that the birth signs and their effects have something to do with this, indirectly. A mortal AE tears its own star, just as the Ge tear stars in the sky, so what if the relationship between a mortal and their sign is a familial one? It's not so much that the constellations change the mortals; rather, the mortals change themselves because they have things in common with the Ge that make up the constellations. Their stars have particular shapes, and some of the creatia that flows out of those shapes has a predisposition toward certain abilities, like opening locks, or poisoning an enemy. The sign they were born under is part of their story, however minor and subtle, and it shapes the stars they tear.

Consider the Mnemoli, one of two varieties of moving stars. During Dragon Breaks, they roam about, windows manipulated by the spirits that created them, allowing closer observation of both the Scrolls and events the Scrolls are incapable of recording.

This idea of the stars as windows from realms of Aetherius, through which the Ge can exert broad influence, finds backing in Lady Cinnabar of Taneth's Mysteries of the Mundus Stones:

The constellations each occupy their own magical domains, as evidenced by the observable energies that emanate from Mundus Stones and their ability to instill power into individuals. We do not know who erected these stones (which can be found across all the provinces of Tamriel) or for what purpose, but their magical resonance tells us clearly that each constellation’s signature is quite unique. This raises questions: were the individual constellations deliberately formed the Magna-Ge, imparting their essence into the trans-constellatory light? Is each constellation a window into a different Aetherial realm, such as Sovngarde or the Far Shores?

And, in that vein, consider the Serpent, the moving constellation, made of un-stars. This I hold to be the holes torn by the Void Ghost as it makes its way into and out of Aetherius to maintain Sovngarde and infiltrate mortal AE to create Shezarrines (Sovngarde being explicitly placed in Aetherius by multiple sources). They are called un-stars because they aren't used the same way that any other star is used; they're not for animating a body, creating a realm in Oblivion, or wistfully looking back at Mundus. They're a set of passages, back doors, moving about per the Void Ghost's design and need. Vivec, in Sermon Thirty-Three, wrote of this:

'I am born of golden wisdom and powers that should have forever been unalike! With this nature I am invited into the Hidden Heaven!'

By which he meant the Scaled Blanket, made of not-stars, whose number is thirteen. Lie Rock became full of foolishness, haggling with the Void Ghost who hides in the religions of all men.

'Stupid stone,' Vivec said. 'To hide in the Scaled Blanket is to make a mark on nothing. His bargains are only for ruling kings!'

So Vivec sent the Hortator to the heavens to shave Lie Rock asunder by the named axe. Nerevar made peace with the south-pole-star of thieving and the north-pole-star of warriors and the third-pole-star, which existed only in the ether, which was governed by the apprentice of Magnus the sun. They gave him leave to wander among their charges and gave him red sight by which to find Lie Rock in the Hidden Heaven.

Note in particular that the Scaled Blanket is called the Hidden Heaven, and therein he haggled with the Void Ghost.

The Serpent is thus used to target the Void Ghost's subtle influence more actively than the other constellations do, on top of allowing the Void Ghost to form Sovngarde. And, here again, the reason the Void Ghost can do this even though it lost its original star is because the story of the Void Ghost comes after the story of Lorkhan. The AE was altered, and it is capable of creating new stars, but they aren't like the one it had before. And, like the roaming stars that make up the Serpent, the Void Ghost is scattered as multiple parts of a greater whole, ever-rambling, that keeps coming back in the form of Shezarrines.