Joseph Beuys (1921–1986) was a German performance artist, sculptor, installation artist, graphic artist, art theorist and pedagogue of art. His extensive work is grounded in concepts of humanism, social philosophy and anthroposophy; it culminates in his "extended definition of art" and the idea of social sculpture as a gesamtkunstwerk, for which he claimed a creative, participatory role in shaping society and politics. His career was characterized by passionate, even acrimonious public debate, but he is now regarded as one of the most influential artists of the 20th century.