Nirn knows only Stasis and Change (Good and Evil are just concepts made by mortals in an attempt to understand the reason of the Stasis and the transition through Change), the two forces, a dual aspect of the Divinity, found in TES.
Magicka is Entropy, a measure of the "disorder" in Creation. By Magnus, the Mathematician, who knows the Alphabet of the When and Where, Nirn, an Entity-Realm not yet known, Became. With the Earth Bones, the Laws of Nirn (Lex Naturalis) were established. Through Magicka, the Change could become Stasis and the Stasis could become Change.
Magicka is the manipulation of the Divinity - the Spark of the Creat