An Octave Higher.

It breaks down how spells are cast into equations that you can actually understand. 

[i]Every person is born gifted with two out of five Traits (Courage, Willpower, Faith, Intelligence and Compassion), and those Traits determine what sort of magic they can use. There are four basic kinds of spells: Summon (produces the corresponding element), Amplify (produces a stronger effect than the basic Summon), Nullify (produces an inverted effect, such as negating gravity for Willpower or cooling hot objects for Courage), and Transform. Spells of different Traits can also be combined to produce more complicated spells, such as combining Water (or Summon(Intelligence)) with Freeze (or Nullify(Courage)) to cast Ice.[/i]