''People are my landscape'', Isaiah Berlin liked to say, and nowhere is the truth of this observation more evident than in his letters. He is a fascinated watcher of human beings in all their variety, and revels in describing them to his many correspondents. His letters combine ironic social comedy and a passionate concern for individual freedom. His interpretation of political events, historical and contemporary, and his views on how life should be lived, are always grounded in the personal, and his fiercest condemnation is reserved for purveyors of grand abstract theories that ignore what people are really like.

This second volume of Berlin''s letters takes up the story when, after war service in the United States, he returns to life as an Oxford don. Against the background of post-war austerity, the letters chart years of academic frustration and self-doubt, the intellectual explosion when he moves from philosophy to the history of ideas, his growing national fame as broadcaster and lecturer, the publication of some of his best-known works, his election to a professorship, and his reaction to knighthood.

These are the years, too, of momentous developments in his private life: the bachelor don''s loss of sexual innocence, the emotional turmoil of his father''s death, his courtship of a married woman and transformation into husband and stepfather. Above all, these revealing letters vividly display Berlin''s effervescent personality - often infuriating, but always irresistible.