In the summer of 1739 Voltaire and his extraordinary and brilliant mistress, Emilie du Châtelet, made a brief sojourn in Brussels. While there Voltaire styled himself ‘the Ambassador of Utopia’ on his invitation cards, and found to his amusement that hardly anyone got the joke – they did not know what ‘Utopia’ meant or where it was. Yet in the light of Voltaire’s lifelong utopian quest for freedom – of thought, of conscience, of expression, of love, of the individual, of nations, of mankind at large – the title he adopted in jest surely applies in earnest.

Roger Pearson is Professor of French at Oxford, and as you would therefore expect he is encyclopedic about everything required to provide a full, rich and fascinating account of his subject – which he duly does. The book is an admirable achievement; it makes a compelling narrative out of the