The influential artist who broke social conventions through their creative expressions is Marcel Duchamp. As a pioneer of the Dada movement, Duchamp challenged traditional notions of art by introducing ideas such as readymades, exemplified by his piece "Fountain". Duchamp's work questioned the definition and purpose of art, encouraging viewers to think critically about artistic intention and societal norms. His impact on contemporary art is profound, as he fostered an environment of innovation and provocation that continues to inspire artists today.