Sir Isaiah Berlin dreaded the physical act of writing, so he paced rooms dictating into tape recorders and to exhausted secretaries, producing some of the most influential political philosophy of the twentieth century. This episode traces his path from a wealthy timber family in Riga, through a childhood memory of a Petrograd mob lynching a sniper during the 1917 revolution, to his family’s escape to Britain in 1921 and his rapid rise at Oxford, where he became the first unconverted Jew to win a prize fellowship at All Souls.

We follow his wartime diplomatic dispatches read by Churchill, his all-night meeting with the poet Anna Akhmatova in Leningrad and the repercussions it brought her, and then unpack his major ideas: the Hedgehog and the Fox (originally a joke), the distinction between negative and positive liberty from his 1958 lecture, and value pluralism, which he insisted was not moral relativism. We close with his founding of Wolfson College on egalitarian lines and the joy his obituaries consistently praised.

• How a lynching witnessed at age seven became the photographic negative of a lifelong defense of the individual
• Why a philosopher’s training made Berlin an unusually sharp intelligence analyst
• Hedgehogs, foxes, and Tolstoy as a fox who desperately wanted to be a hedgehog
• Negative versus positive liberty, and how self-mastery slides into paternalism and coercion
• Value pluralism: why liberty and equality are both objectively good and permanently in conflict