Last week, I spoke at MIT for the 50th anniversary of my father’s work. No one at the conference seemed surprised to learn that Fischer Black had a fairly “free-market” approach to parenting. If we started down a path that wasn’t a very good idea, he figured we’d catch on soon enough. He sometimes gave my three younger sisters and me science kits or educational gifts—but he also loved to come to the mall with us, and would wait around patiently while we tried on clothes. In a world that has become obsessed with judging and condemning, he had a gentle spirit, a nonjudgmental spirit, that I miss daily.