A man should conceive of a legitimate purpose in his heart, and set out to accomplish it. He should make this purpose the centralizing point of his thoughts. It may take the form of a spiritual ideal, or it may be a worldly object, according to his nature at the time being; but whichever it is, he should steadily focus his thought forces upon the object which he has set before him. He should make this purpose his supreme duty, and should devote himself to its attainment, not allowing his thoughts to wander away into ephemeral fancies, longings, and imaginings. This is the royal road to self-control and true concentration of thought. Even if he fails again and again to accomplish his purpose (as he necessarily must until weakness is overcome), the strength of character gained will be the measure of his true success, and this will form a new starting point for future power and triumph.
– James Allen