# The Inner Life, v. I/Fifth Section/XI

SLEEP
I am asked what is the real cause of sleep.
I have not the detailed physiological knowledge which is needed to answer this question fully. But I have always understood that the necessity of sleep is due to the fact that the bodies grow tired of one another. The astral vehicle, which so far as we know is practically incapable of fatigue upon its own plane, since it can work incessantly for twenty years without showing signs of it, very soon becomes tired of the heavy labour of moving the particles of the physical brain, and needs a considerable period of separation from it to enable it to gather strength to resume the irksome task.
The physical body, on its side, also becomes worn out, because while it is in a waking condition it is always spending force a little faster than it can draw it in. With every thought or feeling, and with every muscular exertion, certain slight chemical changes appear to take place. The ordinary machinery of a healthy body is all the while working to counteract this change and to restore the condition previously existing, but in this it never quite succeeds. So that with every thought or action there is a slight, almost imperceptible loss, and the cumulative effect eventually leaves the physical body too exhausted to be capable of further thought or work. In some cases even a few moments of sleep will give the recuperative powers an opportunity to reassert themselves and regain the ground that they have lost, thus restoring the balance sufficiently to enable the machine to go on working.
Students often ask what is the best time for sleep. Unquestionably the rule of nature is that the day is for work and the night is for rest, and no infringement of nature's laws can ever be a good thing. One of the serious evils of our modern unnatural life is that noon is no longer, as it should be, the centre of the day. If a man lived by himself and could regulate his own affairs he could, no doubt, return at once to that obviously natural condition; but, surrounded as we are by a mighty so-called civilization which is in many ways distorted and unnatural, we are unable to follow our individual predilections in this matter, and must to some extent adapt ourselves to the general custom, evil though it be.
It is impossible to lay down rules as to the amount of sleep which is necessary for man, because there is so much difference in constitutions; but when it is possible that sleep should be taken between 8 P. M. and 5 A. M. Some men need the whole of that time, while others may find themselves perfectly healthy on a smaller allowance. Such details of life each man must decide for himself according to his circumstances.
People often ask whether there is any way in which they can control their dreams. The dreamer cannot usually change the course of his dream while it is going on; but the dream-life can indirectly be controlled to a very considerable extent. If a man's thought be pure and high while waking, his dreams will be pure and good also, and a specially important point is that his last thought as he sinks to sleep should be a noble and elevating one, since that strikes the keynote which largely determines the nature of the dreams which follow. An evil or impure thought draws round the thinker evil and impure influences, attracts to him all the gross and loathsome creatures who come near him. These will, in turn, react upon his mind and his astral body, and disturb his rest by awakening all kinds of low and earthly desires. If, on the other hand, a man enters the portals of sleep with his mind fixed upon high and holy things, he thereby draws round him the elementals created by like efforts in others; his rest is peaceful, his mind open to impressions from above and closed to those from below, for he has set it working in the right direction.
The dreaming of ordinary events does not interfere with astral work, because that dreaming is all taking place in the physical brain, while the real man is away attending to other business. Of course if the man, when out in his astral body, devotes himself to thinking over the events of his physical life, he will be unable during the time of such thought to do any other work, but that is a totally different thing from a mere ordinary dream of the physical brain, though when the man wakes in the morning it is frequently difficult for him to distinguish between the two sets of recollections. It really does not matter what the physical brain does so long as it keeps itself free from impure thoughts, but it is undesirable that the man himself should waste his time in introspection when he might be working on the astral plane.