It is a commonplace that if one wants to know what is right or wrong, one goes to consult a religious leader (priest, rabbi, minister, shaman, or what have you.) For many religions, doing what is right is a matter of doing just what God wills.
According to Divine Command Theory (DCT), an action is morally right (either permissible or obligatory) if it accords with God's will. Somehow, God's will determines morality. God is seen as a lawgiver: We are of course free to chose to follow God's laws, but we certainly ought to follow them. This `ought' is all there is to morality. Thus,
Principles of DCT
A. An action X is morally obligatory iff God commands X.
B. An action X is morally impermissible iff God forbids X.
C. An action X is permissible otherwise.
DCT is a popular theory. Many, perhaps most, Islamic, Christian, and Judaic sects adopt DCT. It is worth noting that DCT has a number of advantages. It is reasonably clear cut and decisive; provided, of course, that we understand what to count as God's commands. Certainly DCT has a long and rich tradition. Moreover, DCT is consistent with the intuitions of large numbers of religious people.
Despite DCT's popularity, however, it is conceptually incoherent: ethics is independent of God's will, as the Euthyphro argument shows. Consider first how Plato put the argument.
From Plato's "The Euthyphro", Trans. Lane Cooper:
SOCRATES: Then come, dear Euthyphro, teach me as well, and let me grow more wise. What proof have you that all the gods think that your servant died unjustly, your hireling, who, when he had killed a man, was shackled by the master of the victim and perished dying because of his shackles before the man who shackled him could learn from the seers what ought to be done with him? What proof have you that for a man like him it is right for a son to prose-cute his father, and indict him on a charge of murder? Come on- Try to make it clear to me beyond all doubt that under these conditions the gods must all consider this action to be right. If you can adequately prove it to me, I will never cease from praising you for your wisdom.
EUTHYPHRO: But, Socrates, that, very likely, would be no small task, although I could indeed make it very clear to you.
SOCRATES: I understand. You think that I am duller than the judges; obviously you will demonstrate to them that what your father did was wrong, and that the gods all hate such deeds.
EUTHYPHRO: I shall prove it absolutely, Socrates, if they will listen to me.
SOCRATES: They are sure to listen if they think that you speak well. But while you were talking, a notion came into my head, and I asked myself, Suppose that Euthyphro proved to me quite clearly that all the gods consider such a death unjust, would I have come one whit the nearer for him to knowing what the holy is, and what is the unholy? The act in question, seemingly, might be displeasing to the gods, but then we have just seen that you cannot define the holy and unholy in that way, for we have seen that a given thing may be displeasing, and also pleasing, to gods. So on this point, Euthyphro, I will let you off; if you like, the gods shall all consider the act unjust, and they all shall hate it. But suppose that we now correct our definition, and say w hat the gods all hate is unholy, and what they love is holy, whereas what some of them love, and others hate, is either both or neither. Are you willing that we now define the holy and unholy in this way?
EUTHYPHRO: What is there to prevent us, Socrates?
SOCRATES: Nothing to prevent me, Euthyphro. As for you, see whether when you take this definition you can quite readily instruct me, as you promised.
EUTHYPHRO: Yes, I would indeed affirm that holiness is what the gods all love, and its opposite is what the gods all hate, unholiness.
SOCRATES: Are we to examine this position also, Euthyphro, to see if it is sound? Or shall we let it through, and thus accept our own and others' statement, and agree to an assertion simply when somebody says that a thing is so? Must we not look into what the speaker says?
EUTHYPHRO: We must. And yet, for my part, I regard the present statement as correct.
SOCRATES: we shall soon know better about that, my friend. Now think of this. Is what is holy holy because the gods approve it, or do they approve it because it is holy?
EUTHYPHRO: I do not get your meaning.
SOCRATES: Well, I will try to make it clearer. We speak of what is carried and the carrier, do we not, of led and leader, of the seen and that which sees? And you understand that in all such cases the things are different and how they differ?
EUTHYPHRO: Yes, I think I understand.
SOCRATES: In the same way what is loved is one thing and what loves is another.
EUTHYPHRO: Of course.
SOCRATES: Tell me now, is what is carried carried because something carries it, or is it for some other reason?
EUTHYPHRO: No . but for that reason
SOCRATES: And what is led, because something leads it? And what is seen, because something sees it?
EUTHYPHRO: Yes. certainly.
SOCRATES: Then it is not because a thing is seen that something sees it, but just the opposite-because something sees it, therefore it is seen. Nor because it is led, that something leads it, but because something leads it, therefore it is led. Nor because it is Carried that something carries it, but because something carries it, therefore it is carried. Do you see what I wish to say, Euthyphro? It is this. Whenever an effect occurs, or something is effected, it is not the thing effected that gives rise to the effect; no there is a cause, and then comes this effect. Nor is it because a thing is acted on that there is this effect; no, there is a cause for what it undergoes, and then comes this effect. Don't you agree?
EUTHYPHRO: I do.
It has been said that the best way to detect a person's philosophical talent is to ask them the question, is what is holy holy because the gods approve it, or do they approve it because it is holy? It it an incisive question, one which amounts to a powerful argument against DCT.
|The Euthyphro Argument|
|1||DCT is true.|
|2||If DCT is true, then morality is dependent on God's will.|
|∴||3||Morality is dependent on God's will.||1&2|
|4||Either an action X is morally right because God commands X or God commands X because X is morally right.|
|5||If an action X is morally right because God commands X, then God could have commanded otherwise.|
|6||If God could have commanded otherwise, then morality is arbitrary.|
|∴||7||If an action X is morally right because God commands X, then morality is arbitrary.||5&6|
|8||If an action X is morally right because God commands X, then X is good just in case X is commanded by God.|
|9||If X is good just in case X is commanded by God, then God's commands are good just in case they are commanded by God.|
|10||If God's commands are good just in case they are commanded by God, then goodness is meaningless.|
|∴||11||If an action X is morally right because God commands X, then goodness is meaningless.||8,9&10|
|∴||12||If an action X is morally right because God commands X, then morality is arbitrary and goodness is meaningless.||7&11|
|13||It is not the case that morality is arbitrary and God's goodness is meaningless.|
|∴||14||It is not the case that an action X is morally right because God commands X.||12&13|
|∴||15||God commands X because X is morally right.||4&14|
|16||If God commands X because X is morally right, then morality is not dependent on God's will.|
|∴||17||Morality is not dependent on God's will.||15&16|
|∴||18||DCT is not true.||1,3&17|
The argument is valid. It is in the form of a Reductio Ad Absurdum. We start with a premise (1), draw an inference from it (3), and infer its negation (17). Hence the theory implies a contradiction, so it must be false.
It seems to me that this is more than just valid. It is indeed a sound argument, but perhaps an example would help reinforce intuitions.
In the famous ten commandments of the Judeo-Christian tradition, God commands us to honor our Mothers and Fathers. Thus, according to DCT, it is morally obligatory (right) to honor our Mothers and Fathers. But if honoring our Mothers and Fathers is right merely because God commanded it, then what if God had commanded otherwise? By hypothesis, there's nothing independent of God's will making the honoring of our Mother's and Fathers right. Had God commanded, say, be mean to your Mother and Father, then being mean to our Mothers and Fathers would be right. There is nothing constraining what God commands, since the rightness of the action is solely a matter of just what God happens to command. Thus, because God could have commanded otherwise, morality is arbitrary. Even the DCTist must agree that this is a deplorable result.
But if morality is not arbitrary, then it's not the case that an action is right because God commands it. Rather, it must be the case that God commands the action because the action is right.
There's the rub. If God commands an action because it is right, then there must be some conception of morality which is antecedent to or independent of God's will. The rightness of the action is determined by something other than God's will. Whether or not God commanded or forbade an action, it would still be right, or wrong, as the case may be.
What the Euthyphro Argument shows is that DCT implies a contradiction: morality is dependent on God's will and morality is not dependent on God's will. Hence DCT fails the Standard of Coherence.