With consistency a great soul has simply nothing to do. He may as well concern himself with his shadow on the wall. Speak what you think to-day in words as hard as cannon-balls and to-morrow speak what to-morrow thinks in hard words again, though it contradict every thing you said to-day.

Ralph Waldo Emerson (1803-1882) American essayist, lecturer, poet

Essay (1841), “Self-Reliance,” Essays: First Series, No. 2
    (Source)

Inspired by his reading of Walter Savage Landor in 1833, with passages pulled from his lecture "Individualism," last in his course on "The Philosophy of History" (1836–1837), with other passages from the lectures "School," "Genius," and "Duty" in his course on "Human Life" (1838–1839).