“My icons do not raise up the blessed savior in elaborate cathedrals,” says the artist Dan Flavin. “They are constructed concentrations celebrating barren rooms. They bring a limited light.” Dan Flavin makes art out of long fluorescent bulbs. The light sometimes has color, sometimes not. It is both intense and diffuse. His work imbues a space with a touch of transcendence. It highlights the powerful beauty of simplicity. —E.C.