The third stage of consciousness is situated between spirit and matter. It is this which we experience as sleep, that condition which one calls deep sleep, when one does not even dream. There is so little said about it, and very few think about it. Once a person studies this question of sleep he will find that it is the greatest marvel in the world. It is a living phenomenon. The rest and peace, vitality and vigor, intelligence and life that come to man during the time of sleep are beyond explanation. And yet man is so ungrateful, he is never thankful for this experience which is given to him every day; he is only unhappy when he has lost it. Then nothing in the world can satisfy him, no wealth, no comfort, no home, no position, nothing in the world can replace that experience which is as simple as sleeping, which means nothing and yet is everything.