This is a collection of essays by Isaiah Berlin. His main theme is the importance in the history of thought of dissenters whose ideas still challenge conventional wisdom. Machiavelli, Vico, Montesquieu, Hamann, Herzen and Georges Sorel are the central examples. With his unusual powers of imaginative re-creation he brings to life the ideas of men with original minds who swam against the current of their times and often made entirely new contributions to our intellectual heritage. The book also constitutes a powerful defence of variety - of values, of interpretations of reality and visions of life. It is completed by a full bibliography of Isaiah Berlin's publications, updated for this edition. It is one of four volumes of "Selected Writings", which comprise a comprehensive collection of Berlin's work.