"Yoga, often inadequately translated as "union," represents both the action of awakening to, as well as the description of, our underlying True Nature or pure Being that is the birthing ground of authentic spontaneity.  Nidra or "sleep," on the other hand, is the state in which we are unconscious to True Nature, when we are identified with, and swayed by, thoughts and actions that are based on misperception and reactive patterns.  Yoga Nidra represents the paradox and is the play on the words "sleep" and "awake" as it means "The Sleep of the Yogi," and implies that the normal person is asleep to their True Nature through all states of consciousness--waking, dreaming, and deep sleep--while the yogi is one who is awake to and knows his of her True Nature across all states, even sleep."

-Richard Miller, PhD