may through this simple rule become immense. And the more we increase the force of desire the more we increase results in every field of thought or action. Furthermore, we may cause the forces of concentration and desire to act and react upon each other to great advantage; that is, the more we concentrate for the increase of desire --- worth while desire --- the more powerful and persistent will such desire become; and the more deeply we desire the power to concentrate well --- wonderfully well --- the more life, energy and action we express in the building of real concentration.