The whole mechanism of this world is action and reaction, in the objective world as well as in the world of men. Only, in man there is the possibility of developing that spirit which is called the spirit of mastery, and that spirit is best developed by trying to gain control over one's reactions. Life offers us abundant occasions from morning till evening to practice this lesson. Every move, every turn we make, we are faced with something agreeable or disagreeable, harmonious or inharmonious, either a condition or a person. If we react automatically we are no better than a machine and no different from thousands and millions of people who do so.