Jason Thibodeau over at The Secular Outpost has written a thoughtful discussion and response to the critique I made of Walter Sinnott Armstrong’s arbitrariness objection in my article, “Is Ethical Naturalism more Plausible than Supernaturalism: A Reply to Walter Sinnott-Armstrong.”
Jason suggests that when you disambiguate the premises of Armstrong’s argument, it is formulated as follows:
(1) Either: (i) there is a reason, r, why God prohibits rape; or, (ii) there is no reason, r, why God prohibits rape.
(2) If there is no reason, r, why God prohibits rape, then God’s commands are arbitrary.
(3’’) If there is a reason, r, why God prohibits rape then r is what constitutes the wrongness of rape.
(4’’) If r is what constitutes the wrongness of rape then God’s commands are explanatorily superfluous.
The word “constitute” in premises (3”) and (4”) is a technical term for a particular kind of explanatory relationship. Mark Murphy explains, “The sense of explanation at stake is that of informative identification, as we explain the nature of water by identifying it with H2O or explain the nature of heat by identifying it with molecular motion.”
In my paper, “Is Ethical Naturalism more Plausible than Supernaturalism“, I argued that (4’’) was false; (4’’) relies on a particular principle:
PI: If A is constituted by B, and someone has reasons, r, for bringing about B, then A is constituted by r.
However, PI is false. Consider a counter-example drawn from Stephen Sullivan. Consider Giorgio who is bachelor. Giorgio is unmarried because he prefers to live alone. Given that the property of being a bachelor is constituted by the property of being an unmarried man, and Giorgio’s love of living alone provides a reason for him to be an unmarried man, PI entails that the property of being an unmarried man is constituted by the property of preferring to live alone, but this is clearly false. Giorgio’s preference for living alone provides him with a reason for being a bachelor, in the sense that it is what motivates him to continue to be one, but his preferences do not constitute him being a bachelor. There are, after all, many people who are bachelors who would prefer not to live alone.
Thibodeau agrees that this counter example refutes PI, he suggests a repair:
“Is Flannagan correct that the arbitrariness argument relies on PI? I don’t see that it does. PI is extremely implausible on its face and does not capture the insight involved in the argument. In any event, the argument does not need it. A defender of AA need not be committed to PI but to something much more narrow in scope. A defender of AA can accept that PI is not generally true but assert that it is true of phenomena that involve reasons in the way that moral obligations do.
Morality involves reasons in two different respects; if I am morally obligated to do something, then I have a reason (or reasons) to do it. But, more than this, if I am obligated to do something, then there are reasons that I am under that obligation. For example, a parent is morally obligated to care for her children. But there are also reasons for this obligation. A parent is so-obligated because she is partly responsible for bringing the child, who is helpless on his own, into existence. A stranger living 500 miles away from the child has no reason to provide for that child and, again, there are reasons for this lack of obligation (namely, that the stranger does not know the child (or even that the child exists) and so does not have a special connection to the child and can do very little in any event).”
For this reason Thibodeau suggests that instead of PI, the inference in (4’’) should be based on a more specific principle PR:
“PR: If A is constituted by B, A is grounded in reasons and is itself a reason, and someone has reasons, r, for bringing about B, then A is constituted by r.
This enables the inference in (4’’) to go through and it is not subject to the Giorgo counter example.
This is a thoughtful response, and a considerably better one than the one proposed by Richard Carrier. Despite this, however, I suggest that PR is false for the same sort of reasons PI is.
Consider a second example drawn from Stephen Sullivan. Certain laws are constituted by an Act of Parliament. Laws constitute reasons for action, they tell us what we can and what we cannot do. There are reasons why citizens are under laws. Parliament has reasons for passing particular Acts of Parliament. However, it is clearly not the case that Parliament’s reasons can be informatively identified with a law. The reasons existed prior to that law. Even if Parliament irrationally ignored the reasons and did not make a particular law, the reasons for that particular law would still exist while the law would not.
Consider another example. Under certain circumstances a decision made by a Family Court Judge constitutes a Protection Order, judicial decisions constitute reasons for action and there are reasons why we have court decisions of this sort. Consequently PR entails that if a judge, reflecting on the evidence submitted, decides that he or she has good reasons for ruling a particular way then those reasons themselves constitute the Protection Order, prior to, and independent of, any judicial decision. But,that is clearly false. These reasons existed before the judge’s decision and would exist, even if the Judge ruled the other way, yet no Protection Order exists unless and until the Judge makes the ruling. So the reasons cannot be identical with the Protection Order.
Examples like this, I think, illustrate the problem with arguing that if God has reasons for issuing the commands he does then those reasons themselves, and not his commands, constitute our obligations.
 Mark C Murphy, “Theism, Atheism, and the Explanation of Moral Value”, in Is Goodness without God Good Enough: A Debate on Faith, Secularism and Ethics, Eds Robert K Garcia and Nathan L King (Lanham: Rowman & Littlefield Publishers, 2008) 127.
 Stephen Sullivan, “Arbitrariness, divine commands, and morality” International Journal of Philosophy of Religion 33 (1) (1993) 37-39.