Anti-art is a loosely used term applied to an array of concepts and attitudes that reject prior definitions of art and question art in general. Somewhat paradoxically, anti-art tends to conduct this questioning and rejection from the vantage point of art. The term is associated with the Dada movement and is generally accepted as attributable to Marcel Duchamp pre-World War I around 1914, when he began to use found objects as art. It was used to describe revolutionary forms of art. The term was used later by the Conceptual artists of the 1960s to describe the work of those who claimed to have retired altogether from the practice of art, from the production of works which could be sold.