In his Metaphysics, Aristotle discusses meaning of "being as being". Aristotle holds that "being" primarily refers to the Unmoved Movers, and assigned one of these to each movement in the heavens. Each Unmoved Mover continuously contemplates its own contemplation, and everything that fits the second meaning of "being" by having its source of motion in itself, moves because the knowledge of its Mover causes it to emulate this Mover (or should).