Humans are an artificial race born from the machinations of the elderthings and their desires. Since the banishment of the elderthings to the deep and the creation of the cage of heaven humans now live under light-bearer's rule.
The vast majority of human scriveners are what are known as channels, rather then be a proper scrivener they bind their motion with that of a greater being (In modern times the light-bearers) they lack the detailed knowledge of the magic they perform but make up for it in having access to the knowledge of things older then any human can hope to be.
While most human scriveners are channels, their are those that dedicate their whole lives to learning the truths of the Ethereal, at the end they will have learned enough that they can start to alter the world, often they know a few weak spells as barely a century is far from enough time to grasp the truths of the worlds. However some go in knowing this and seek one truth over all others the truth of the sands, and play with the very nature of motion preventing their decay or calling their own motion back once it is lost. They are the sand-sages or necromancers and they will twist themselves to live far longer then what is normal for their kind. They will grow to ages and power rivaling those of the other races.
Some sages took a separate route then the sand-sages and they transcribe their minds into semi-sentient artifacts called grimoires, any one can then bind their minds with this grimoires and become a contractor, they promise their minds to the grimoire and gain power at the price of their mind being added to the grimoire.