Divine command ethics is best understood as an account of the deontological (deon = duty in Greek) part of morality that concerns duty or obligation. Moral deontology’s chief concepts are moral requirement (obligation), moral permission (rightness), and moral prohibition (wrongness). On a divine command conception, actions are morally wrong only because God forbids them; actions are morally only because God does not forbid them; and actions are morally obligatory only because God commands them. Contemporary divine command theorists disagree about how to conceive of the precise relation between, for example, being morally wrong and being forbidden by God. On one view, the property of being morally wrong is identical with the property of being forbidden by God; on another, the former property is distinct from but logically comes before God’s command. A third view is that God’s forbidding an action causes it to be morally wrong.

Monotheists of all stripes should, at least initially, be sympathetic to an ethics of divine commands. Judaism, Christianity, and Islam share the view that the Hebrew Bible has authority in religious matters. Both Exodus 20:1-17 and Deuteronomy 5:6-21, which recount the revelation of the Decalogue, portray God as a commander, instructing the Chosen People about what they are to do and not to do by commanding them. It seems natural enough to suppose that the AUTHORITY of the Decalogue depends on the fact that it is divinely commanded. It is possible, of course, to understand these divine commands as nothing more than God’s emphatic endorsement of a moral code whose truth is independent of them.

Being omniscient, God would know such moral truths, and being supremely good, God would want to communicate them to the Chosen People. On this view, commands are God’s way of transmitting important moral information to humans. But it is also possible to understand the truth of the moral code expressed by the Decalogue as dependent on the divine commands.