"Oh friends, there is no friend" - this enigmatic sentence at the beginning of Derrida's book quotes an entire tradition of philosophical, political, and literary texts from Aristotle to Montaigne, Nietzsche, and Kant, and on to Carl Schmitt, Bataille, and Blanchot. It opens up a theory of friendship and enmity, the political implications of which Derrida elaborates. In our tradition, the book's hypothesis suggests, the genealogy of the political is linked to the pair brother/friend. The concepts of the political and of friendship refer back to a questionable schematism of descent: origin, gender, species, blood, nature, and nation. The politics of friendship aims for a new concept of the political and of democracy.