Alister McGrath has observed: “The idea that human morality might ultimately be grounded in something built into the fabric of the universe itself has obstinately refused to die out. It possesses a certain intuitive plausibility, even if its conceptual clarification has proved to be immensely difficult.”1 McGrath is surely correct on each count. In the present day, when the world is so morally fragmented, the idea of a natural and universally binding moral law perhaps seems more implausible