The presence of the soul or essential self within the body is what constitutes “being awake.” There is no consciousness apart from the presence of at least a minimal sense of the soul working in and through a body.
The soul or essential consciousness always withdraws during sleep and such withdrawal is the esoteric definition of sleep. A developed consciousness is active in a subtle or psychic/spiritual worlds and learns and works during the sleep of the body. But people ordinarily have only occasional glimpses of that night life. The bridging of the two worlds of night and day is called “continuity of consciousness” and is made possible by subtle evolutionary changes in the etheric matrix of the brain.
“When man reaches the stage where he succeeds in penetrating the etheric
veil which normally effectively separates the physical personality from the
subjective spheres, he gains what is known as “continuity of consciousness”.
Once this dividing screen has been ruptured, this will allow free access to the
higher etheric planes. Continuity of consciousness is the gift of retaining a
comprehensive recollection of both the inner and outer life, with the power of
preserving full awareness of every sphere of activity, whether substantial or
subjective, and whether occurring while awake or during the hours of so-called
sleep. For this purpose enhanced sentiency, linked with telepathic
interplay, will have to be developed.”