" All things were formed of energy, arrangements of bundled light that were subject to natural law. The awareness of this truth, defined to absolute perfection, granted the mage-trained their influence. To know a thing, to encompass its full measure in respect was to hold its secrets in mastery. Life-force was the basis of all power. "

― Janny Wurts , The Curse of the Mistwraith (Wars of Light and Shadow, #1)