Persistence is an essential factor in the procedure of transmuting desire into its monetary equivalent. The basis of persistence is the power of will.
Will-power and desire, when properly combined, make an irresistible pair. Men who accumulate great fortunes are generally known as cold-blooded, and sometimes ruthless. Often they are misunderstood. What they have is will-power, which they mix with persistence, and place back of their desires to insure the attainment of their objectives.
~ Napoleon Hill, Think & Grow Rich (1937)