Magic works because of the interaction between the physical world and the Aether. The Aether is inhabited by Spirits which can be drawn across ‘the barrier’ by certain individuals. A Spirit absorbs energy when it is held in the physical world, which creates an aura of cold around where a Spirit is held in the physical world.
An individual who is able to pull spirits from the Aether (called a Magus) into the physical world has a quality known as Gravitas. An individual with more Gravitas finds it easier to pull spirits from the Aether and hold them in their person.
A Spell is the release of a Spirit back into the Aether, which causes either the release of energy, or the creation of matter. A type of Magus known as a Sorrer knows how to direct the energy of a Spell so that it does not happen in a chaotic and deadly matter. This process is partialy mental, but contains an important physical component that resembles our martial arts.
An Enchantment is when a Magus known as a Mantzer traps a Spirit in an inanimate object. This imbues the object with elemental properties and an intelligence that can be controlled by the Mantzer.