A pianist practises for hours to command his fingers and gain a touch which will bring the soul from his music, without in the least realizing that so long as he is keeping other muscles in his body tense, and allowing the nervous force to expend itself unnecessarily in other directions, there never will be clear and open channels from his brain to his fingers; and as he literally plays with his brain, and not with his fingers, free channels for a magnetic touch are indispensable. To watch a body _give_ to the rhythm of the music in playing is most fascinating. Although the motion is slight, the contrast between that and a pianist stiff and rigid with superfluous tension is, very marked, and the difference in touch when one relaxes to the music with free channels has been very clearly proved. Beside this, the freedom in mechanism which follows the exercises for arms and hands is strikingly noticeable. With the violin, the same physical equilibrium of motion must be gained; in fact it is equally necessary in all musical performance, as the perfect freedom of the body is always necessary before it can reach its highest power in the use of any secondary instrument. In painting, the freer a body is the more perfectly the mind can direct it. How often we can see clearly in our minds a straight line or a curve or a combination of both, but our hands will not obey the brain, and the picture fails. It does not by any means follow that with free bodies we can direct the hand at once to whatever the brain desires, but simply that by making the body free, and so a perfect servant of the mind, it can be brought to obey the mind in a much shorter time and more directly, and so become a truer channel for whatever the mind wishes to accomplish. In the highest art, whatever form it may take, the law of simplicity is perfectly illustrated. It would be tiresome to go through a list of the various forms of artistic expression; enough has been said to show the necessity for a free body, sensitive to respond to, quick to obey, and open to express the commands of its owner. XVI. TESTS ADOPTING the phrase of our forefathers, with all its force and brevity, we say, "The proof of the pudding is in the eating." If the laws adduced in this book are Nature's laws, they should preserve us in health and strength. And so they do just so far as we truly and fully obey them.