`The fox knows many things, but the hedgehog knows one big thing.` This fragment of Archilochus, which gives this book its title, describes the central thesis of Isaiah Berlin`s masterly essay on Tolstoy. There have been various interpretations of Archilochus` fragment; Isaiah Berlin has simply used it, without implying anything about the true meaning of the words, to outline a fundamental distinction that exists in mankind, between those who are fascinated by the infinite variety of things (foxes) and those who relate everything to a central all-embracing system (hedgehogs). When applied to Tolstoy, the image illuminates a paradox of his philosophy of history, and shows why he was frequently misunderstood by his contemporaries and critics. Tolstoy was by nature a fox, but he believed in being a hedgehog.