What is a spell?

A group of robed figures chant meaningless syllables in a circle, while a nude man in the center carves a piece of flesh from his thigh with a curved, silver knife, and throws it into a fire. The fire turns bright blue, and he shouts in triumph. A hundred miles away, his mortal enemy stubs his toe, the first a series of unlucky occurrences which will plague the rest of his life.

An orc riding a lindwyrm chases a frantically fleeing human horseman across the steppe. The horse is fast, and gaining distance. The orc clicks his tongue and draws a bone wand from his saddlebag. He breathes in deeply, points the wand, and howls while making an occult gesture with his other hand. The ground below the horse moves as though alive to wrap around its hooves, and as the animal's fetlock snaps, the rider is thrown forward, breaking his neck as he lands. The orc massages his temples, nursing a headache while his wyrm finishes off the horse and begins tearing into its unfortunate rider.

What the hell is going on here?

The Puzzle

Most of the categories people use to make sense of what happens in the world are kind of made up, and don't have strict conditions for their applicability. No one knows how many different sequences of fundamental physical events there are which can rightly be called "storms," which is part of why it is pretty hard to predict for sure whether a storm is going to form in the next hour just by looking at a few events. Unless one of those events is a successfully performed stormcaller spell, in which case for some reason you can be nearly certain that one of the many sequences of physical events you'd say counts as a "storm" will happen!

This weirdness isn't just with spell effects. A particular stormcaller ritual calls for the practitioners to be humans wearing blood red robes. But is "being blood red" a unique, determinate property? No, of course not; it has countless physical determinates, since there are countless ways a physical object can be a particular shade. The robes could be made of a material which, under ordinary lighting conditions, looks blood red due to the light it reflects. Why it reflects that wavelength of light could have to do with any number of physical properties different. Or perhaps it isn't even a reflective material, but rather florescent, and at the right temperature or after being "charged up" with high-energy radiation it glows blood red under any lighting conditions. Once again, there are many ways it could be, physically speaking, such that it emits light that way. And so on. But no matter how it is that the robes are the right color, the ritual succeeds so long as they are colored blood red!

Combine these two and magic seems hardly imaginable. Events involving non-natural, mind-dependent properties with vague applicability conditions can reliably cause other events of different, similarly non-natural kinds. Meanwhile, the fundamental events (which actually fall into natural kinds) underlying these phenomena always work out to make things turn out the way we'd expect. You can't figure out an explanation for why the stormcaller ritual works by finding causal relationships between all the different determinate ways to perform the ritual correctly, and all the different determinate physical phenomena which count as "storms," because there are no causal processes capable of explaining the rules for the spell at that level of fundamentality. And yet the spell still works!

So what is a spell? How is all this possible?

Spells Are Not Grounded How Things Are

The reason why spells can't be explained by the more fundamental properties of the objects and events involved in their performance and effects is that spells are not grounded by how things actually are. The causal processes involved simply don't depend for their existence on the real properties of any events and objects. A spell is grounded in how something seems, and not how it actually is. Seems to whom? To the person who created the spell, of course.

But more on that later. The power to make a spell effect happen characterizes the spell's components, and is not reducible in any way to ontological grounds of those components. These robes are blood red, which is why they're able to function (along with other components) in calling storms. But it simply doesn't go any deeper than that. Its in virtue of the robes being blood red that they're able to function in calling storms, and not in virtue of whatever it is in virtue of which they are blood red. That's why it doesn't matter whether they're blood red in virtue of being reflective, or florescent, or under certain lighting conditions, or whatever. Reduction and explanation aren't transitive here: the robes being usable as spell components reduces to and is explained by their being blood red, and their being blood red will (for each case) reduce to and be explained by some physical properties they have, but their being usable as spell components has absolutely nothing to do with those physical properties.

Where Do Spells Come From?

Some beings have a certain talent, or if you like, The Talent. The Talent is the ability to make things be the case by willing that they be the case. The Talent is very rare among the mortal races, but among dragons and fairies, it is ubiquitous (and there's debate as to whether the gods have the Talent or not). Most users of the Talent are only good at making certain sorts of facts obtain or certain kinds of events happen using their Talent. It's also extremely difficult to cultivate, so most with the Talent never get any better at using it. Among mortals, thousands of times more Wielders of Talent have died never able to do more than light a candle at will than have managed to reach the level of being able to create a spell. That's why most spells were introduced to mortals through bargains with beings like fairies and dragons, who are both generally more naturally Talented than mortals, and have more time to improve.

And it is Wielders of Talent who create spells, because only the Talent (and maybe the gods, if what they're doing isn't using Talent) can introduce new, irreducible properties into the world and make them characterize the medium-sized dry goods and ordinary events with which they transact. Sufficiently powerful Wielders can simply will that it be the case that one kind of event has the power to cause another, and thus introduce new laws of nature.

But that's why magic is grounded in how things seem, and not how they are. The creator of a spell does not have some wide but specified variety of physical phenomena in mind when they will that a certain ritual will cause a storm to appear. They have in mind a concept, one with the semantic range of the word "storm." When they thus bend the world to their will and create a new law that a storm will happen when a certain ritual is performed, the law connects any instance of something they would regard as successful performance of the ritual, to an occurrence which would satisfy their idea of an appropriate storm.

For the same reason, no two castings of the same spell produce exactly the same effect. The law is as vague as the concepts it's based on, and permits a wide range of effects to occur, as long as they'd fit with what the spell's creator had in mind. But unless you look very closely, more closely than the creator of the spell was thinking when they made it, you won't notice the difference.

Why Is Casting Spells Difficult?

The minds of almost all beings are repulsed by magic. Something deep in their psychology, deeper than any of their other senses, is a sense of just how wrong magic is. The Talent is when Wielders, not bothering to fully understand nature, assert upon it their impoverished understanding and force it to obey. Spells are when they do that, and make it permanent, twisting nature's very laws into an image rooted in whatever conceptual system they happened to have. The part of every being's mind that longs for reality itself more than concepts and conventions can sense magic, and revolts against it. When spells are cast, untrained animals flee, and most people are unable to restrain a flash of terror and hatred.

Sorcerers aren't much different from anyone else in that respect. Even having an intention to enact spell components is mentally taxing, to say nothing of actually going through with it. Therefore, sorcerers practice just picking a few spells each day and resolving to only cast those spells, to constrain their own intention to use magic enough to get through the day without having a mental breakdown. They similarly incur mental fatigue each time they cast one of those spells, limiting how many times they can do so without endangering themselves. Part of getting better at sorcery is getting better at tolerating the sense of ontological wrongness that accompanies willfully practicing magic, which is why better sorcerers can prepare more distinct spells at a time and cast more frequently.