Book excerpt: Originally delivered in 1971 as the first Cambridge lectures in memory of Bertrand Russell, Problems of Knowledge and Freedom is an erudite and cogent synthesis of Noam Chomsky's moral philosophy, linguistic analysis, and emergent political critique of America's war in Vietnam. In the first half of this wide-ranging work, Chomsky takes up Russell's lifelong search for the empirical principles of human understanding, in a philosophical overview referencing Hume, Leibniz, Wittgenstein, and others. In the following half, aptly-titled "On Changing the World," Chomsky applies these concepts to the issues that would remain the focus of his increasingly political work of the period. These include the war in Indochina and the Cold War ideology that supported it, the centralization of U.S. decision-making in the Pentagon and the growing influence of multinational corporations in those circles, the politicization of American universities in the post-World War II years, along with his reflections on the Cuban missile crisis and the mass liberation movements of the era. This is the third in a series of Chomsky's early political books reissued by The New Press. The others are American Power and the New Mandarins and For Reasons of State. Book jacket.