In recent years the German-Jewish critic and philosopher Walter Benjamin has come to be regarded as one of the leading intellectual figures of the 20th century. Yet much of his work, particularly his theoretical writing, remains elusive. This book offers a new, comprehensive interpretation of Benjamin's ""oeuvre"", focusing on the central ideas of mourning and melancholia. According to Max Pensky, the contradictions in Benjamin's thought - from his early ""mystical"" theory of literary criticism through his adoption of Marxist and surrealist doctrines to his final version of ""materialist historiography"" - can be understood as his long-term personal and theoretical response to these two ideas. For Benjamin, melancholia was both a subjective disposition that threatened the individual with incapacitating sadness and a highly sophisticated mode of understanding that provided a form of spiritual insight into the structure of historical reality. Benjamin's goal, in Pensky's view, was to transform his own melancholy character into an instrument of critical acumen and, ultimately, revolutionary action. Through close readings of the ""Origin of the German Play of Mourning"" (Ursprung des deutschen Trauerspiels), the essays on surrealism and Baudelaire, and the massive, unfinished ""Arcades Project"", Pensky demonstrates that Benjamin's attempt to work through this ""melancholy dialectics"" lies at the core of his mature thought.