» Wed Mar 09, 2011 2:12 am
http://www.imperial-library.info/search/node/y%27ffre.
But more importantly: spend a lot of time reading EVERYTHING at The Imperial Library that has anything to do with Aedra and Daedra. There's this thing about TES lore, and it's one of my favorite things about the whole setting, but it can be maddening in situations like this: absolutely every piece of lore you read is biased. It's all written (or said) by a character in-game, and every single one of those characters will insert their own agenda, ignorance or other spin. The game writers never use their own voices, and I'm sure sometimes they haven't even decided what really happened when they're writing up multiple accounts of it. With regards to the original nature of the gods, the Altmeri (and particularly the Psijics) have written the most about it, but my personal hunch is that the Yokudan creation myth is closest to the original truth (in addition to being awesome). But there's no way to know for sure, and since people can mess with time, it might no longer be the actual truth even if it once was.
For instance, there's evidence that the Nine Divines were created by men at the dawn of the Second Era and are not the same beings as the previous gods they're based on; or if they are, they have been bound up by mythic magics strong enough to prevent them from behaving as they naturally would -- all so that the Cyrodiilic Empire would have a divine right to rule over all of Tamriel. And these gods really exist and so far as the cosmology of Tamriel is concerned, they always have; it's just that they haven't always always existed. (And from the Skyrim teasers, perhaps the bubble will be bursting soon...)
Anyway, the most basic fact you need to start with is that Aedra and Daedric Princes are pretty much all one race, called et'Ada. Quick summary of the Monomyth: the entirety of existence is a resonant fractal interaction between the original forces of Is and Is-Not. Is came first, but Is-Not sprang into being before time so that Is could recognize itself by contrast; they started mixing, necessitating Time (also a sentient being, names include Akatosh) to keep track of which mixes happened when, and over Time other et'Ada emerged from the flux. Some had more Is in their makeup, some had more Is-Not; the classical standpoint is that the Is-aligned became Aedra and the Is-Not-aligned became Daedra. There are some obvious exceptions to this (Lorkhan, Meridia) and the real truth is that within the Empire "Aedra" really just means "you're allowed to worship this one."
By the way, I've seen people associate Aedra with Law and Daedra with Chaos in the classic alignment scheme. This is exactly backwards. The state of Is represents pure potential, undefined and chaotic; magic, i.e. the ability to violate natural law, comes from Is. The state of Is-Not is calm, empty, perfectly smooth, the very definition of order (i.e. Law); the ability of any object to be defined depends on the ability to say that object "is not" other things.