On one occasion when these facts were put forward verbally, the objection was made that the statement about the number seven does not apply to colours, since there are others beyond the red and violet rays, invisible to the eye. But even in this respect the comparison with colours holds good, for, in fact, the human being expands beyond the physical body on the one side, and beyond the Spirit-Man on the other; only to the methods of spiritual observation of which occult science here speaks, are these extensions of the human being “spiritually invisible,” just as the colours beyond red and violet are physically invisible. This explanation becomes necessary, because the opinion so easily arises that occult science does not seriously apply itself to scientific thinking, but treats such matters unscientifically. However, one who carefully considers the meaning of the statements made by occult science will find that in reality it is never at variance with genuine science; neither when it brings forward the facts of natural science as illustrations, nor when its statements are directly connected with natural research. CHAPTER III. SLEEP AND DEATH The nature of waking consciousness cannot be fathomed without observing that condition which man experiences during sleep, and the problem of life cannot be approached without studying death. Any one failing to perceive the importance of occult science may distrust the manner in which it studies sleep and death. Occult science is, however, capable of appreciating the motives from which such distrust arises. For there is nothing incomprehensible in the assertion that man exists for an active, purposeful life, that his acts depend on his devotion thereto, and that absorption in such conditions as sleep and death can result only from a taste for idle dreaming, and can lead to nothing else than vain imaginings.