This article compares the thinking of Andrzej Walicki and Isaiah Berlin on the nineteenth-century Russian intelligentsia and on Soviet totalitarianism. It suggests that Berlin saw totalitarianism as an externally imposed political system, whereas Walicki understood totalitarianism to depend both on external pressure and inner coercion. The article draws on a variety of published and unpublished sources, including personal interviews with Walicki and Berlin’s archives at the New Bodleian Library in Oxford, England.