While offering a comprehensive review of existing Klimt criticism, this book aims to shed new light on the artist's output by arguing that his works challenge a number of established boundaries, thereby performing a continual crossing of thresholds. The present study explores Klimt's threshold universe by means of detailed analyses of a wide range of his works from all phases of his prolific career, complemented by references to his correspondence. At the same time, it assesses the painter's vision vis-a-vis both relevant debates about creativity, and the broad cultural context in which he operated.