[Footnote 18: The suggestion for this chapter came from Reverend William J. Lockington's little book on "Bodily Health and Spiritual Vigour", Longmans, Green and Co., London, New York, Bombay and Calcutta, 1914.] Religion, as we have seen in the course of this book, does very much for health, but according to the great principle of nature, reaction is equal to action in compensation and health undoubtedly also accomplishes very much for religion. Indeed there are a great many troubles commonly presumed to be of the spirit and a great many supposed disturbances of the spiritual life that are really only manifestations of ill health of one kind or another, or at least of some hampering of bodily function reflected in the mind. This has always been recognized by all the great authorities in the spiritual life, and none have insisted more than the writers even of the highest mystical theology on the necessity for taking proper care of the body if the spirit is to be free for religious life. Desolation, that is that feeling of utter dissatisfaction with religious exercises and difficulty in continuing them of which so much is said in spiritual literature, is very often nothing more than dyspepsia. What is familiarly called the "blues" or the "blue devils", that is the state of depression in which nothing seems hopeful and the future seems very blank indeed, is a common experience among mankind generally and is very often dependent on {320} some disturbance of the digestive tract. There is a well-known expression in English according to which the answer to the question "Is life worth living?" is "That depends on the liver", meaning not only the person that does the living, but also that large organ in the right upper abdominal quadrant, the largest, heaviest organ in the body, disturbances of which it is no wonder cause serious interference with a number of the functions of both mind and body. Many a long-faced person indeed who thinks himself pious is only bilious, and many a sad-eyed visionary who is quite ready to proclaim himself religious is only what the ancients called atrabilious and needs some liver regulator as badly as ever Horace thought he needed hellebore in the spring.