Lightness and darkness, an age-old motif in the visual arts: artists’ perpetual preoccupation with light. It also represents the concept of the duality of all existence that one encounters in nearly every culture. Günther Uecker reduces this to a very simple “formula”: two spirals that rotate around themselves, one dark, the other light. As material, he uses—in addition to a little paint on the unprimed ground—his universal material, the nail, which here describes circling lines, just as, with Fontana, the cut of the knife describes straight lines. Uecker combines the materiality of the nail with the aspired ideality of the image. After 1960, the artists of the ZERO group, to which Uecker once belonged, countered the Nouveau Réalisme of their friends in Paris with a “new idealism.” Uecker’s two-part object was acquired by the Friends in 1984.