One side of our nature fears the Infinite, and we experience a chill when the methods of this world obtrude themselves there. We have convinced ourselves that the part of our inner life which we call the soul is something more sacred and mysterious and nearer to the Infinite than our ordinary faculties. What victims we are of words! What is the value of this feeling, and how did it arise? Our appreciation of the beautiful, in art and nature, is equally extra and transcends our practical faculties. Man’s belief in another world--an ideal world of the absolute good--is, of course, the result of his strong reaction from the pain, the struggle, the incompleteness of this world. Evolution is a hard road to travel. Being born is evidently not a pleasant experience for the baby, and in this world man is constantly struggling through new experiences into a higher and larger life. His measure of happiness is never full and he looks for compensation in another and better world. He does not see that there can be no better world--that pain and struggle and disappointment are necessary for his development, and that to long for a state in which these things do not exist is like the stream longing for a dead equilibrium. All power and all growth come from a break in the repose of the physical forces. There is no power in a uniform temperature, nor in water at a dead level. Mechanical power comes down an incline, vital power is a lift on an up-grade--all growing things struggle upward; the vegetable and animal world lift the earth elements up against gravity into an unstable equilibrium. Mechanical things run down the scale toward a stable equilibrium. Our life goes on by virtue of some principle or force in matter that tends constantly to break up the stable into the unstable, to force the elements into new chemical combinations. Our machines dissipate energy in doing work; the living body conserves energy in the same process. It grows strong by the obstacles it overcomes, up to the limits of its powers. The clock runs down, the energy we put into it in winding it up is dissipated; but the growth of a living body is a winding-up process, a drawing-in and a storing-up process. In the wood and coal we burn is stored up the heat of the sun. In burning them and driving machinery by means of the heat developed, the energy is dissipated. In manual labor the human body dissipates energy also, and it is the same solar energy that the engine dissipates, and it does it in the same mechanical way; and it is constantly replenished from without through the food consumed. But the human or living engine stokes itself. It is a clock that winds itself up, a gun that loads and points itself. Because the living body in its final analysis turns out to be a machine as absolutely dependent upon mechanical and chemical principles as any other machine, there are those who see no radical difference between the mechanical and the vital.