“Sunlight and shadow are the same.” Quoting Emerson’s paradox, the late Ethel Roosevelt Derby opened a photographic laboratory she had established in the basement of the Harvard Semitic Museum in memory of her daughter, who had died young a few months before. That paradox succinctly summarizes the physical basis for photography and epitomizes as well something unique about culture and the human spirit: adversity often brings blessings “in disguise.”