Heinrich Heine's role in the formation of Critical Theory has been systematically overlooked in the course of the successful appropriation of his thought by Marx, Nietzsche, Freud, and the legacy they left, in particular for Adorno, Benjamin and the Frankfurt School. This book examines the critical connections that led Adorno to call for a "reappraisal" of Heine in a 1948 essay that, published posthumously, remains under-examined.