And here let me interject what to me has become a fundamental principle upon which invariably I rely. It will be recalled what I have said elsewhere of _selfish_ and _unselfish_ occupations. It is the selfish occupations that produce nerve-exhaustion. Those that are unselfish seldom result in the disturbance of the harmony or equilibrium of our nature--whether we regard it as physical, mental, or spiritual. This may seem to be a trancendental statement--perhaps it is. But I am confidently assured of its essential truth. That man or woman who is truly engaged in an unselfish work--a work that is for the good of others--has a right to look for, to expect and to receive from the great All Source of strength, power and serenity all that is needed to keep the body, mind and soul in harmony, consequently in perfect health and free from worry. Hence the apparent paradox that, if you would care for yourself you must disregard yourself in your loving care for others. One great reason why worry produces nervous prostration is that it induces insomnia. Worry and sleeplessness are twin sisters. As one has well said: "Refreshing sleep and vexing thoughts are deadly foes." Health and happiness often disappear from those who fail to sleep, for sleep, indeed, is "tired Nature's sweet restorer," as Young in his _Night Thoughts_ termed it. Shakspere never wrote anything truer when he said: Sleep that knits up the ravell'd sleave of care, The death of each day's life, sore labor's bath, Balm of hurt minds, great Nature's second course, Chief nourisher of life's feast. Or, where he spoke of it as Sleep that sometimes shuts up sorrow's eye, Steals me awhile from mine own company. Even the Bible makes sleep one of the special blessings of God, for we are told that "He giveth His beloved sleep." The sacred book contains many references to sleeplessness and its causes. Undoubtedly most potent among these causes is worry. The worrier retires to his bed at the usual hour, but his brain is busy--it is working overtime. What is it doing? Is it thinking over things that are to be done, and planning for the future? If so, there is a legitimate excuse, for as soon as the plan is laid, rest will come, and he will sleep. Is he thinking over the mistakes of the past and sensibly and wisely taking counsel from them? If so, he will speedily come to a decision, and then sleep will bring grateful oblivion. Is he thinking joyful thoughts? These will bring a natural feeling of harmony with all things, and that is conducive to speedy sleep? Is he thinking of how he may help others? That is equally soothing to nerves, brain and body, and brings the refreshment of forgetfulness.