Modern art giants Jean Dubuffet, who died in 1985, and Pierre Soulages, who is now 100 years old, both defied the rules handed down by the art world establishment. They were both fascinated by the unprecedented expression of prehistoric art, as well as the powerful energy of African and Oceanic art. Opera Gallery places work by Dubuffet and Soulages alongside pieces, on loan from private collectors, that inspired their breakaways from tradition. —E.C.