Book excerpt: "In individuals, insanity is rare; but in groups, parties, nations and epochs, it is the rule.” Friedrich Nietzsche (1844–1900) was a German philosopher, poet and Latin and Greek scholar whose work has exerted a profound influence on Western philosophy and modern intellectual history. Because of Nietzsche's evocative style and provocative ideas, his philosophy generates passionate reactions. His works remain controversial, due to varying interpretations and misinterpretations of his work. In the Western philosophy tradition, Nietzsche's writings have been described as the unique case of free revolutionary thought, that is, revolutionary in its structure and problems, although not tied to any revolutionary project. Some prominent elements of his philosophy include his genealogical critique of religion and Christian morality; the related theory of master–slave morality; the characterization of the human subject as the expression of competing wills, collectively understood as the will to power; and influential concepts such as the Übermensch and the doctrine of eternal return. Content: Beyond Good and Evil The Genealogy of Morals The Birth of Tragedy or, Hellenism And Pessimism The Antichrist Thus Spake Zarathustra: A Book for All and None The Case of Wagner The Twilight of the Idols The Will to Power (Vol. 1&2) The Gay Science or, The Joyful Wisdom We Philologists Ecce Homo: How One Becomes What One Is The Greek State The Greek Woman On Music and Words Homer's Contest The Relation of Schopenhauer's Philosophy to a German Culture Philosophy During the Tragic Age of the Greeks On Truth and Falsity in Their Ultramoral Sense Selected Personal Letters