18. Ralph Waldo Emerson
Emerson was a poet, an essayist, a philosopher, a lecturer, the mentor of Henry David Thoreau, and the leader of the transcendentalist movement in the United States in the early to mid-19th century. Emerson championed individualism throughout his life, and his works remain major influences on philosophers and transcendentalists. His work was influential on Friedrich Nietzsche and William James, the author and presenter of the first course of education in psychology within the United States. Emerson was the most influential of all American philosophers until well into the twentieth century, and remains influential to scholars today.
