The Birth of Tragedy (1872) was Nietzsche's first book; The Genealogy of Morals (1887) one of his last. Both are about the conflict between the moral and aesthetic approaches to life, the impact of Christianity on human values, the meaning of science, the famous contrast between the Apollonian and Dionysian spirits, and the other themes that dominated Nietzsche's life and have made him a figure of the first magnitude for contemporary thought.