Berlin's main theme in these essays is the importance in the history of ideas of dissenters whose thinking still challenges conventional wisdom - among them Machiavelli, Vico, Montesquieu, Herzen and Sorel. With his unusual powers of imaginative re-creation, he brings to life original minds that swam against the current of their times, and in the process offers a powerful defence of variety in our visions of life. Roger Hausheer's introduction surveys Berlin's whole oeuvre, and the full bibliography of his pubication has been updated for this Pimlico edition.