Harold Rosenberg's seminal work investigates the evolving nature of art in the mid-20th century, questioning the very definitions and boundaries that had previously governed artistic creation and reception. Through a series of critical essays, Rosenberg examines the shift from art as a mimetic representation to art as an event or action, deeply influenced by the rise of abstract expressionism and conceptual art.

Harold Rosenberg's 'The de-definition of art' is widely regarded as a foundational text in art criticism, offering a prescient analysis of the radical shifts occurring in the art world during the latter half of the 20th century. Critics and scholars frequently cite Rosenberg's concept of the 'action painting' and his broader arguments about the dissolution of traditional artistic categories as essential to understanding contemporary art. The book's enduring influence lies in its intellectual rigor and its challenge to conventional ways of thinking about art's purpose and value.