All abortion is wrong. All human life is precious. On those simple principles there should be no uncertainty. But should all abortion be against the criminal law? Western societies have grappled with that question for at least half a century. It is part of a wider issue: the right relationship between the moral and the civil law. This is a particularly acute question for the Catholic Church, and it would be over-optimistic to say it has reached a settled conclusion. But by constantly challenging the acceptance of abortion the Church does a great service to the common good, for public debate needs some voice that argues from fundamental moral principles even if the majority cannot, on reflection, accept all of them immediately.