Isaiah Berlin is renowned for his analysis of the ideas that have influenced or transformed societies. He has a deep commitment to liberty and pluralism, and has devoted the half-century and more of his professional life as a teacher and lecturer to exploring the conditions which allow these ideals to flourish, and those which threaten them. Utopianism, cultural history, relativism, Fascism, romanticism, nationalism - the range of the eight essays collected here have as their common theme varieties of anti-rationalism. The longest essay, on Joseph de Maistre, is published here for the first time. The title is drawn from a remark by Kant: Out of the crooked timber of humanity no straight thing was ever made.