An old fish swims past two younger ones and nods. “Morning, boys. How’s the water?” The two swim on, and after a while one of them looks at the other and asks, “What the hell is water?” David Foster Wallace told that story in his 2005 commencement speech at Kenyon College, later published as This Is Water. His point was that the most obvious, important realities are often the hardest ones to see and talk about, precisely because they’re everywhere. The firm is one of those realities. Almost ever...