
Isaiah Berlin (1909–1997) was an Oxford philosopher and historian of ideas, who made a key contribution to the development of political theory with his essay ‘Two Concepts of Liberty’ (1958). More famous still is his study on Tolstoy’s view of history, The Hedgehog and the Fox (1953). His writings on liberty and pluralism are a part of the intellectual bedrock of the open society. The best concise biography of Berlin is Alan Ryan’s article in the Oxford Dictionary of National Biography.
One way of approaching Berlin’s life and works is through his admiration for, and identification with, the 19th century Russian writer, radical, and publicist, Alexander Herzen. Berlin came upon Herzen’s works by chance in the London Library while researching his biography of Karl Marx (1939). It was an accidental discovery that had important consequences. Berlin came to regard Herzen as ‘the most eloquent and convincing preacher’ of a fundamental truth – that monist systems of thought are responsible for inhumanity and injustice on a colossal scale. He believed that ‘political fanaticism of this type, no matter how pure the motive, how noble the goal, invariably leads to blood’, and that no century illustrated this ‘in a more dreadful fashion’ than his own. He recommended Herzen as the antidote.

