COMMENT:A philosophical history of rationality, with emphasis on its relations to its social competitors, be it the authority of Faith, tradition, disorganized magical ideology, or sophisticated relativism. Defends the "Siege Mentality" view, where the success of Reason was a historical accident, and its position is always potentially precarious. For all its remarkable cognitive success (science), rationality breaks down when applied to politics, ethics, and other human concerns, which have repercussions on the hard cognitive side as well. Gellner argues Reason cannot attain a self-justifying transcendentality, but can be embodied in a particular sort of culture. Contains many broad insights into current forms of irrationalism and even paranormal beliefs. It perhaps exaggerates the intellectual strength of "suicide of reason" views, but this is a book well worth reading.