Can we run our lives and govern our societies by reason? The question provoked Socrates to redirect philosophic inquiry in a political direction, and it has remained fundamental to Western thought. Martin Heidegger explored this problem in his profound critique of the Western metaphysical tradition, and Leo Strauss responded to Heidegger with an attempt to recover the classical idea of the rule of reason. In The Responsibility of Reason, Ralph C. Hancock undertakes no less than to answer the Heideggerian challenge. Offering trenchant and original interpretations of Aristotle, Heidegger, Strauss, and Alexis de Tocqueville, he argues that Tocqueville saw the essential more clearly than apparently deeper philosophers. Hancock addresses political theorists on the question of the grounding of liberalism, and, at the same time, philosophers on the most basic questions of the meaning and limits of reason. Moreover, he shows how these questions are for us inseparable.