Marcel Duchamp’s ready-mades transformed the very definition of art. By presenting ordinary industrial objects as artworks, he dismantled notions of originality, skill, and aesthetic value. Fountain (1917), a porcelain urinal turned on its back and signed “R. Mutt,” remains one of the most radical gestures in art history, an ironic provocation that shifted the focus from object to idea. Art became not what was crafted, but what was chosen. In this conceptual revolution, the artist’s will replaced the hand, making thought itself the medium.