“It is a time for fragments,” said Marcel Duchamp. It was 1934 and Duchamp was in his studio, discussing his work The Large Glass with the author Anaïs Nin. Duchamp was suggesting that the artistic response to societal upheaval and the fragmentations of war, with its division and destruction, was an art of fragments. Other artists have worked likewise. “Time for Fragments” explores a Duchampian idea through the art of Marianna Castillo Deball, Anish Kapoor, William Kentridge, Cy Twombly, Andy Warhol, and other pioneers. —E.C.