No one who has felt the life-changing pull of Emerson's enormous planetary mind has ever doubted his power or his greatness, though we are often puzzled to know whether he is primarily a poet, an essayist or a philosopher. Richard Geldard is not puzzled at all by this; he has written a book that plainly shows Emerson to be essentially a teacher, the Socrates of Concord, a man with a message that we need to hear today. Previous generations...