Moreover, what is the use of cramming them down his throat when you can squirt them into him with a psychological hypodermic? That is the charming thing about suggestion. All control, then, is control through mental imagery. You have had this experience, for example. As you stood in a railroad station and a locomotive came thundering in, you have had, for a moment, an impulse--not only an impulse,--you have had the picture in your mind of throwing yourself under the locomotive. From a casual inspection of the company I should suppose that none had tried that experiment as yet. Why? Because you were able to remove that picture from your mind and substitute for it another--a picture of the presumable appearance of things in a very short time after you had made the experiment, or the vista of a long and happy life stretching out before you, or of obligations to family and friends. Any one of these pictures will serve the purpose. But if the time ever comes when that picture of going under that locomotive gets firmly fixed in your mind, nothing except physical force from without can prevent your going under the wheels. Every motor idea that comes into our minds tends to work itself out into action. That is the secret of the hypnotic sleep, in which the person who is under your control, through pictures produced in his mind, automatically carries these things out into action. Mental imagery is the secret of life, and control of mental imagery means the control of mankind. Self-control is the control of one's own imagery.