Hans Arp (1886–1966) was a key figure of the European avant garde. Co-founder of the Dadaist movement, a close friend of Wassily Kandinsky, El Lissitzky, Theo van Doesburg, and the Surrealists, he developed his own distinctive form of Concrete Art incorporating both organic and geometric forms. For the painter and sculptor known variously as Hans or Jean Arp, Concrete Art was “something that grows organically.” His inclusion of the aleatory principle in the creative process may be regarded as a means of self-objectification: what is made is replaced by what it has become.