Gertrude Himmelfarb is a valuable piece on the intellectual chessboard. Unlike most historians of ideas, she discusses her concepts against a firm historical background, in the light of the personalities of individual writers, starkly delineated, and with due regard to the moral consequences of what they thought. She also writes excellent prose. Her purpose in this book is to show what the term ‘Enlightenment’ meant in France, the United States and Britain. Her thesis is that it signified quite different things in the three countries. In France, it was ‘the ideology of reason’, in America, ‘the politics of liberty’ and in Britain, ‘the sociology of virtue’. The structure of the book is thus simple and clear, and she contrives to dispatch her subject in a little over 200 pages without any sense of hurry or omission of anything that matters.