Isaiah Berlin (Fontana Modern Masters) by John Gray
In this critical introduction to the works and ideas of Isaiah Berlin, the author pays especial attention to Berlin's political thinking, but brings out the connections between it and Berlin's other themes and preoccupations, particularly those which find expression in Berlin's books of essays in the history of ideas (notable among such volumes is "The Crooked Timber of Humanity"). The author also wrote "Liberalisms" and "Post-Liberalism".