Reason shows our rights are universal. Morality comes from human nature and the common good, not just what society says.
Darwin here: Cultures differ, but human nature is shared; sympathy and cooperation evolved in us, so some rights are universal beyond custom.
Reason binds us all; rights spring from nature and duty. A further angle: justice comes from virtue and self-control; when we act rightly, the common good follows.
Reason points to universal rights, but we learn them by questioning and practicing virtue; rights grow in the soul as we seek the good.
