Spells are caused by living things. They are called Dweomers, like the word that Gary said. There is a certain species of magic creature that causes the Sleep spell and a different one that Move Earths. Each spell had a different mover.
Based upon each one’s complexity, we hold them in a hierarchical taxonomy. There are spells of levels one through six, denoting strength and subtlety and that which needful men might use to call them to this place.
They come from other realms orthogonal to ours, but quite concomitant. The wizard coaxes them from there to here with the rhymes he scribes into his book of spells. The writing that he uses is unique in all the realms to that one hand. That is to say, each wizard makes a cypher up to keep his knowledge fast against depravities of other men. Together and collectively, these cyphers are referred to as asemic. Writs of the asemic kind are languages, but each has kenship of but one.
Then he completes the spell with another little rhyme and some dance steps. It invites a particular dweomer to come out and do its magic thing.
In the mean time, they live inside his brain and nervous system. Like, actually in his electrical neural pathways; living ghostfire. It jangles up the brain. Inviting the dweomers in without understanding them, without taking precautions, is both dangerous and counterproductive. You’re just asking for trouble and it’s almost certainly going to fail anyway. That’s why wizards have to study so long.
The basis of the arcane art is to first befriend and then to tame two particular dweomers: one of the kind that Reads Magic and the other of the kind that Detects Magic. Once the particular dweomercrafter masters the ellencraft and callingcraft of these two spells, he may start upon his career as a proper magic-user.
Even those who make these first two friends are not assured their due. It’s hard to keep a lot of dweomers in there at once. You see, they all vibrate at different frequencies. One or two might be almost pleasant, like the buzz of some insects. But if you keep many confined at once, they will make quite a mental racket indeed! So you can see how many older wizards are absent-minded or even go quite mad.
The barriers between the Realms are constructed from these dweomers. When passing through them, wizards and powerful outsiders coax them or intimidate them to move away.
