Distinguished scholars--Jurgen Habermas, Claus Offe, Douglas Kellner, and Martin Jay, among others--draw upon historical, theoretical, and biographical information to assess Marcuse's philosophy, from its grounding in classical German idealism, through the break with Heidegger, to his role in the American counterculture of the sixties and seventies. Indispensable for anyone interested in an in-depth understanding of one of the most burning issues of our time: the relation of critical theory to social action.