The divine command theory (hereafter: DCT) is the metaethical theory that moral values are whatever is commanded by a god or gods.
DCT is the first horn of what has come to be known as the Euthyphro dilemma (after its first appearance in Plato's dialogue Euthyphro): “Is the morally good whatever is commanded by god, or does god command what is in fact morally good?”
The theory runs into four main philosophical problems. First, it implies that what is good is arbitrary, based merely upon god's whim; if god had created the world to include the values that rape, murder, and torture were virtues, while mercy and charity were vices, then they would have been. It's not, of course, possible to reply that god wouldn't have commanded such things because he wouldn't command evil, for on this theory it's only his command that makes them evil.
Secondly, it implies that calling god good makes no sense — or, at best, that one is simply saying that god is consistent: ‘God does whatever he commands’.
Thirdly, it commits the naturalistic fallacy; to explain the evaluative claim that murder is wrong (or the prescription that one should not commit murder) in terms of what god has or hasn't said is to argue from a putative fact about the world to a value (to argue to an ‘ought’ from an ‘is’). If I ask why I shouldn't commit murder, the DCT answer is: ‘because god commands you not to’, but I can then ask why I should do what god commands. If the answer is that god created me, I can ask why I should obey my creator, and so on.
Fourthly, it seems to lead to the conclusion that all moral values are at the same level (because what is wrong is simply to disobey god); that is, committing murder is no worse than telling a lie, because in the two cases I have equally disobeyed god.
There are also more theological or practical problems, not least of which is the fact that few if any religions claim to have god's word concerning every possible situation. These value gaps usually concern situations that the writers of ancient religious scriptures couldn't have foreseen, such as those involving advanced technologies (especially biological and medical).
Thus it's possible for a follower of DCT to want to follow god's commands, but to be helpless in the face of ethical problems not covered by any known commands. (By contrast, other ethical systems (such as utilitarianism and Kantian deontology), leave no such gaps, either because they offer a method for calculating the right course of action from very general principles (utilitarianism) or because they place the source of ethical knowledge in our own rationally-discovered intuition of the Moral Law (as in Kant).
It's possible for the religious believer simply to swallow or to brush off some or all of the philosophical objections. For example, writers like William of Ockham argue that if god had commanded murder, then murder would indeed have been morally obligatory. Indeed, Ockham goes so far as to say that god could change the moral order at any time. Thus Ockham embraces DCT wholeheartedly; his view has been characterised as being that ‘god's command is good’ is analytically true. He can be thought of as saying: ‘God could have commanded us to commit murder, and then it would have been obligatory — but he didn't, so it isn't...so what's the problem?’
Most writers, however, have felt that they need to give some response to the problems sketched above. Duns Scotus is responsible for one approach that has been influential in modern times. He argues that, for one set of moral values at least, god could not have commanded otherwise because they are necessary (omnipotence, of course, means being able to do anything, but the logically impossible is essentially nonsensical, and not part of anything). Some moral values, on the other hand, are contingent on particular decisions of god, and thus he could have commanded otherwise. Thus, for example, that murder is wrong is a necessary truth, and though god commanded us not to murder he couldn't have done otherwise, nor can he revoke his command; keeping the Sabbath day holy, on the other hand, is only contingently wrong, and god could have commanded otherwise, and could revoke his command. This is similar to a more recent approach developed by Richard Swinburne.
In developing what he calls a Modified Divine Command Theory, R.M. Adams distinguishes between two meanings of ethical terms like ‘wrong’ and ‘wrong’: the meaning that atheists can grasp (which in fact Adams explains in roughly emotivist terms), and the meaning that has its place in religious discourse (that is, commanded or forbidden by god). Because god is benevolent, the two meanings coincide; god is, however, free to command other than he has done, and if he had chosen to command, for example, that murder was morally right, then the two meanings would break apart. In that case, even the religious believer would be forced to accept that it was correct to say both that murder was wrong and that god commanded us to commit murder.
Sources & reading
- Paul Helm [ed.] Divine Commands and Morality (1981: Oxford, Oxford University Press) ISBN: 0-19-875049-8
- Brad Hooker “Cudworth and Quinn” (Analysis 61, 2001)
- Philip L. Quinn “Divine command theory” (in Hugh LaFollette [ed.] The Blackwell Guide to Ethical Theory)
- Eleonore Stump & Norman Kretzmann “Being and goodness” — in Thomas V. Morris [ed.] Divine & Human Action (1988: Ithaca, Cornell University Press) ISBN: 0-8014-9517-2
- R.G. Swinburne The Coherence of Theism (1977: Oxford, Clarendon Press) ISBN:0-19-824410-X (chapter 11)