I've been trying to put this into a presentable form, but making it a story seemed to get frustrating quite quickly- a story about the lectures in a class really won't bring in the readers. Instead, I'll present the concepts and ask you to chew on them.

All of magic is a matter of a soul imposing the power of its will to change the universe in certain ways. Most spells are essentially instructions to one or more spirits to make those changes.

What those spirits can do is where it gets interesting. The easiest thing for them is to open apertures to other places. The earliest form of magic was 'creating' fire, but it really was just opening a tunnel to where some fire already was burning. They can animate things. If they envelop something, they can change its shape. (I found the spirits from Wan's tale in Legend of Korra particularly inspiring here).

Another aspect to this is that the spirits see things outside of the limits of time; they can look at something and see its earlier state. Because there are so many of them idling around, they sometimes watch the past and future of things, and some will rearrange things, hoping to hint to the observant what might be coming soon.

In the earliest days of magic, creating fire was the basic trick. Transforming into powerful or fast creatures was another. Some of those earliest wizards chose to make themselves powerful, invulnerable, able to fly and always holding onto their ability to shoot fire without the risk of being burned. They eventually became dragons.

Many of the existing magical species came about like that.

The giants and trolls developed from proto-wizards who used their influence to make themselves tough, big, and strong. Their 'magic' was dedicated to sustaining this state of enhancement, until that's all they could do with it, and they stayed that way.

Goblins adapted to the needs of miners- they toughened their skin, shrunk to a size better able to delve deep, breathe shallow and require little water. Eventually they learned to eat the valuable metals they found for ease of transport. It turned their skin hard and metallic.

[ another lecture extract ]

The first overtly magical people were the spirit talkers. They could sense the presence of spirits and ask for their help. Most didn't know why or how it functioned, only that it did; if they asked with the deepest part of themselves, the spirits would answer and bend the rules for them.

Let us take a moment and be specific about this: the spirit-talkers were not having out-and-out conversations. They sensed the presences that others could not, and in some desperate moments would discover that their most primal need was being fulfilled, in defiance of all that their life's experience had told them was possible. They called- the spirits answered.

Fire spontaneously ignites a lone frozen log for a talker driven into winter wilderness. A mother is given the strength to lift a tree that was holding her son underwater during a flash flood. What made these miracles so very interesting is that, once a spirit had learned how to do a trick for a talker, they could do it again with a little practice (and sufficient will and patience).

Was it one spirit or many? Do the spirits talk amongst themselves? Those early spirits may have been very few, and now there are many, as the ghosts of the magical dead eventually lose their memory of self and join the invisible choir. Or perhaps those early spirits were much greater in scope, but they have divided themselves as more speakers are born and require attention.

In some, this manifested in superior physicality. In others by the exaggeration of their deepmost longings. Yet others were focused in their desire to understand the world around them. The children of these gifted ones carried forward their unique trait, taught by their parents how to gain the same advantage, using it to gain power and influence over their neighbors.

From a greedy man named Gulbor was descended a line of squat digging types, who modified themselves with claws and thick skin to better mine the earth and defend the treasures they found there. These became goblins.

An abused boy from the far north named Otun-jo used his magic to grow big and strong- stronger and bigger than anyone. Due to his strength-based popularity, he was most prolific. His children became giants and trolls.

A wise woman found that her green thumb was more than just lucky. She modified her plants in ways that defied what we now call biochemistry. Some only stayed enchanted for the season, where others drew the enchantments into their growth cycle, making them magical on their own. It may have saved humanity in the last ice age, but some of those wondrous vines merged with other descendents of her garden, creating bizarre and ofttimes dangerous new flora. The ones considered magical tend to be self-moving or flourish in the presence of fertilizing substances from magical sources.

 

I might be misunderstanding that part, but if they can do that then the first law of Gamp's Law of Elemental Transfiguration, specifically the one about conjuring food, wouldn't exist, because spirits could just open a portal and 'create' food by transporting it.

 

It's more a matter of translation- spirits can't respond to human language, but they can (or have developed the code for) duplicating the physical properties of what is presented to them. It's true that a spirit could retrieve an ice cream sundae from somewhere else, so long as the caster could communicate where it is, or to recall one from being recently Vanished.

Gamp's Law says [probably- this is headcanon but I don't think it veers too far afield] that a perfect transfiguration makes the object an entirely new thing, with no vestiges or history of being the previous thing, down to its elemental composition (not Carbon-Oxygen-etc; more its Aristotelian nature). The first exception is making food- I take that as saying 'one cannot create the nutritive value of food from something without it'. Other arguments on the forum have bandied this about, so we may need to source that to work out the kinks in the theory.