The Fatal Conceit: The Errors of Socialism is a book written by the economist and political philosopher Friedrich Hayek and edited by the philosopher William Warren Bartley. The book was first published in 1988 by the University of Chicago Press. Questions have been raised about how far Bartley was the editor and how far the author. The title of the book derives from a passage in Adam Smith's The Theory of Moral Sentiments (1759), though the exact phrase does not occur in Smith's book.