An eye can threaten like a loaded and leveled gun, or can insult like hissing or kicking; or, in its altered mood, by beams of kindness, it can make the heart dance with joy.

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

Essay (1860), “Behavior,” The Conduct of Life, ch. 5
    (Source)

Based on a course of lectures, "The Conduct of Life," delivered in Pittsburg (1851-03).