In this final volume, Isaiah Berlin enters a profoundly interesting last phase in his life. He is as prolific a correspondent as ever, but the publication of new essay collections produces a striking change in tone, as readers seek clarification of his ideas. Many of these letters throw new light on his thought, and deal with issues of overriding importance to today's world. Berlin dwells on pluralism of values and cultures, political liberalism, the defense of democracy, and the challenge posed by fundamentalism. But there is also gossip to close friends, reflections on music, the arts, and...