Enlightenment (more appropriately known as Awakening), is the process of filling "the cup" with Consciousness. It is the ongoing process whereby the monadic consciousness seats itself in the Physical Unit. Awakening is a physical process and depends largely proper Development of the physical unit. A physical unit that has been properly Developed will awaken (i.e. enlighten) as part of the natural maturation process.
Sharp, Michael (GA). The Great Awakening: Concepts and Techniques for Successful Spiritual Practice.