The gigantic will-powers of the world, the world-movers, can bring their Prana into a high state of vibration, and it is so great and powerful that it catches others in a moment, and thousands are drawn towards them, and half the world think as they do. Great prophets of the world had the most wonderful control of the Prana, which gave them tremendous will-power; they had brought their Prana to the highest state of motion, and this is what gave them power to sway the world. All manifestations of power arise from this control. Men may not know the secret, but this is the one explanation. Sometimes in your own body the supply of Prana gravitates more or less to one part; the balance is disturbed, and when the balance of Prana is disturbed, what we call disease is produced. To take away the superfluous Prana, or to supply the Prana that is wanting, will be curing the disease. That again is Pranayama — to learn when there is more or less Prana in one part of the body than there should be. The feelings will become so subtle that the mind will feel that there is less Prana in the toe or the finger than there should be, and will possess the power to supply it. These are among the various functions of Pranayama. They have to be learned slowly and gradually, and as you see, the whole scope of Raja-Yoga is really to teach the control and direction in different planes of the Prana. When a man has concentrated his energies, he masters the Prana that is in his body. When a man is meditating, he is also concentrating the Prana.