The Science of Freedom completes Peter Gay’s brilliant reinterpretation of the Enlightenment of the philosophes begun in The Enlightenment: The Rise of Modern Paganism. In that book, Mr. Gay analyzed the struggle in which the philosophes pitted classical pagan thought against their Christian heritage. In the present book, which can be read independently as a social history of the Enlightenment, he describes the philosophes’ environment, their program, their view of progress, of science, of art, of society, and of politics. He explains the complex relationship and interaction between the two Enlightenments — the philosophic movement and the environment from which the philosophes drew ideas and support. His masterful appraisal opens a new range of insights into the Enlightenment’s critical method and libertarian vision.