Ralph Waldo Emerson, who went by his middle name Waldo, was an American essayist, lecturer, philosopher, abolitionist, and poet who led the Transcendentalist movement of the mid-19th century. He was seen as a champion of individualism and critical thinking, as well as a prescient critic of the countervailing pressures of society and conformity. Friedrich Nietzsche thought he was "the most gifted of the Americans", and Walt Whitman called him his "master".