“At the heart of liberty is the right to define one’s own concept of existence, of meaning, of the universe, and of the mystery of human life.” So said Justice Anthony Kennedy in the 1992 Supreme Court case Planned Parenthood v Casey. This viewpoint that defines humans by their capacity to choose is pervasive in American law and policy, but it disregards a stubborn fact – we are naturally limited to be dependent on others. Carter Snead has more.