The power which resides in man is new in nature, and none but he knows what that is which he can do, nor does he know until he has tried.
Source: In The Ultimate Success Quotations Library, 1997.
-- Ralph Waldo Emerson, (May 25 1803-1882), US philosopher, poet, essayist; He was the main spokesman of his time for moral optimism and belief in the individual: Self-Reliance, 1844.