In October 1960, Arman, Yves Klein, François Dufrêne, Raymond Hains, Martial Raysse, Daniel Spoerri, Jean Tinguely and Jacques Villeglé, and art critic and philosopher Pierre Restany founded the Nouveau réalisme group. Joined later by Cesar, Mimmo Rotella, Niki de Saint Phalle, and Christo, the group of young artists defined themselves as bearing in common their "new perspective approaches of reality." They were reassessing the concept of art and the artist for a 20th-century consumer society by reasserting the humanistic ideals in the face of industrial expansion.