The first prerequisite for a normal mental life is the acceptance of all biological facts. Biology is ignorant of all delicacy. The possible presence of broken glass, coupled with the fact that man lacks hoofs, makes it imperative for man to wear shoes. The man who is unconsolable over the fact that his feet are too tender in their bare state to tread roads, and the man who decides to ignore broken glass and to walk barefoot, are courting mental and physical suffering of the most useless type. He who accepts the fact that his feet are tender and broken glass dangerous, and goes forth, shod in the proper footgear, will probably remain whole, mentally and physically. When we realize that our unconscious is ours and ourselves, but not of our own making, we shall know our limitations and our potentialities and be free from many fears. No better way has been devised for probing the unconscious than the honest and scientific study of dreams, a study which must be conducted with the care and the freedom from bias that characterize the chemist's or the physicist's laboratory experiments. Furthermore, dream study and dream study alone, can help us solve a problem which scientists have generally disregarded or considered as solved, the tremendous problem of sleep. Algebra and Latin, which are of no earthly use to 999/1000 of those studying them, are a part of the curriculum of almost every high school. Sleep, in which we spend one-third of our life, is not considered as of any importance. How could we understand sleep unless we understood the phenomena which take place in sleep: dreams? Even Freud, whose research work lifted dream study from the level of witchcraft to that of an accurate science, seems to have been little concerned with the enigma of sleep and sleeplessness. This book is an attempt at correlating sleep and dreams and at explaining sleep through dreams. Briefly stated, my thesis is that we sleep in order to dream and to be for a number of hours our simpler and unrepressed selves. Sleeplessness is due to the fact that, in our fear of incompletely repressed cravings, we do not dare to become, through the unconsciousness of sleep, our primitive selves. In nightmares, repressed cravings which seek gratification under a symbolic cloak, and are therefore unrecognizable, cause us to be tortured by fear. The cure for sleeplessness and nightmares is, accordingly, the acceptance of biological facts observable in our unconscious and our willingness to grant, through the unconsciousness of sleep, dream gratification to conscious and unconscious cravings of a socially objectionable kind which we must, however, accept as a part of our personality. February, 1921. 121 Madison Avenue New York City TABLE OF CONTENTS I. SLEEP DEFINED 1 II. FATIGUE AND REST 11 III. THE FLIGHT FROM REALITY 20 IV. HYPNOGOGIC AND HYPNOPOMPIC VISIONS 32