John Danaher has a nice article on the epistemological objection to divine command theory. I have talked about this before, and why I don't think it works, but it's interesting to have a more developed form to look at. Danaher gives a simple version of the objection:
(1) DCTs, either explicitly or implicitly, include an epistemic condition in their account of moral obligations, viz. you must either know or successfully receive communication (implying knowledge of divine commands in order for you to be morally bound).
(2) There are such things as reasonable non-believers (i.e., non-believers who do not violate any epistemic duties in their non-belief) and for these reasonable non-believers (RNBs), satisfaction of the epistemic condition is not possible.
(3) Therefore, on DCT, there are no moral obligations for non-believers.
This is a nice way of conceiving the objection, because I think it makes the reply very clear. As anyone knows who has read me before on DCT before, whenever faced with an objection to divine command theory, I always ask, "Would this be a problem for William Warburton, or someone like him?" And this formulation makes it relatively easy to say: he would deny both (1) and (2). The first part of (2) is the easy one; on Warburton's account, non-believers are trying to have moral obligations without a moral obliger, which he regards as a contradiction, and therefore they are not reasonable. On Warburton's account, non-believers should not be saying that there are general moral obligations; they can say that things are in bad taste or that they are stupid ways of being and doing good, but he is quite insistent that nothing can create an obligation except a wise and good agent with power of sanction, and nothing can create a moral obligation except a supremely wise and supremely good agent with universal power of sanction. And (1) Warburton would deny for exactly the same reason that we say, if a law has been promulgated, that ignorance of the law is no excuse.
In order to consider the problem with (1) a little better, it is worth remembering another thing that I always bring up when people object to divine command theory, namely, that you have to do justice to one of its clearest advantages. If you are positivist about legal obligations -- as a great many people are -- DCT is the only available unified theory of obligation that allows moral obligations to be universal in scope. If we're talking about legal obligation and moral obligation, there are only a limited number of views:
(a) Legal obligation is part of, or at least derives, directly or indirectly, from moral obligation, which does not itself depend on any kind of obligation-making process or action.
(b) Legal obligation is created by law-making process of some sort, while moral obligation is independent of any such process or action.
(c) Both legal obligation and moral obligation are created by an obligation-making process or action of some sort.
For (a), legal obligation is a kind of moral obligation, although often a qualified kind. Natural law theorists and Kantians accept such a view. A benefit of (a) is that it provides a unified theory of obligation: all kinds of obligation ultimately get the same explanation. Legal positivists have historically tended to accept (b), but (b) has the obvious disadvantage that it allows there to be two kinds of obligation, and no unified account of why they are both obligations. To get the latter, you need (c). But there are only two major forms of (c). Legal obligations are always recognized to be limited in scope, because they are formed by a process or action that is limited in scope, so the question is whether this is true of moral obligations or not. If you say, "Yes," this is some kind of social relativism: morality changes from society to society. If you say, "No," moral obligation has to be created by an obligation-making process or action of universal scope. And that, as they say, all men call God. If you are a positivist about law, you have some reason to be positivist about morality, because your reasons for being a positivist about law have analogues for being a positivist about morality; if you are a moral positivist who wants a morality that is universal, as most people do, you have reason to be a divine command theorist, because that is precisely what is offered by DCT. And thus whenever we look at an objection to divine command theory, we should always ask: Would this objection work applied to a lesser obligation, like a law passed by Congress? It is, for instance, simply not true that such laws require an epistemic condition -- ignorance of the law is no excuse, if the law was properly promulgated -- so we would need a very good reason to think that moral obligations differed on this point.
Danaher notes that some divine command theorists accept something at least like an epistemic condition; but, of course, perhaps they shouldn't. I confess I'm not impressed by the argument Danaher gives, which is that metaethicists tend to hold that moral obligations have an epistemic condition because our usual platitudes about moral obligation seem to require one. Danaher's example provides a good reason for why I'm not impressed: we tend to think moral obligations are "action-guiding and motivationally salient". It is true that an obligation can't guide your action if it's not known, but this does not mean that its being an obligation depends on its actually guiding your action. If you know it and don't act on it, it didn't guide your action; if you know it and don't care about it, it is not motivationally salient; but in neither case can we conclude that it is not an obligation. You don't get out of the obligation not to murder simply by being a sociopath who doesn't care about it and so ignores it. What we mean is that a reasonable person aware of the obligation will let it guide his action and be relevant to his motivations; it is not an account of what is required for it to be an obligation. And with 'ought implies can', Danaher's other example, Kant's own version of the maxim depends on his having an account of obligation diametrically opposed to that of divine command theory. On Kant's account of obligation, obligation is built into reason itself, and therefore, since it's impossible for a reasonable person not to have 'epistemic access' to their obligation, the only 'can' he himself ever intends is the 'can' of being able to act on it, at least in principle. But even if we ignored that, on Kant's account, it is unacceptable to do an action you are obligated to do for any reason other than that it is what you are obligated to do, but you can talk to people about the topic and discover that this is not what most people assume -- most people think that if you inadvertently did what your obligation requires, you fulfilled your obligation, even if only by luck. And if you accept that this is true, then 'ought implies can' only means that an obligation implies that you can in principle do what fulfills it, whether you know it or not.
It's worth thinking about why we say that ignorantia juris non excusat. And the reason is found in another legal maxim: Leges instituuntur cum promulgantur, laws are imposed when they are promulgated. We require that laws be published with signs that they are from the appropriate authority and intended to be published as law. But if laws are instituted simply in their being communicated in this way, whether someone learns about it is irrelevant to whether they are obligated by it. You can honestly not know that you have to pay your taxes, and you can still be obligated to pay your taxes, if the law requiring you to do so was promulgated as such by the appropriate authority. We might take your ignorance into account in determining punishment; but not in determining whether you were obligated. And the only exceptions to this are the exceptions that prove the rule -- that is, the only time this is the exception in the case of legal obligation is when the law itself provides for ignorance being an excuse.
Danaher's defense of (2) seems to me to be marred by a confusion between "having epistemic access to X" and "knowing X". His point, of course, is that since rational non-believers don't believe that something is a divinely promulgated law, they can't know it. But whether they believe it or not is irrelevant to the question of whether they have epistemic access to it. I think part of the problem may be that he is assuming that if you have epistemic access to something you will know it if you fulfill your epistemic duties; but this, I think, is quite generally false. For instance, I have epistemic access to how many shirts I have in the dryer, and I am not in any way currently violating any epistemic duties with regard to my shirts, and yet I don't know how many shirts I have in the dryer because I haven't gone to look -- I have no duty to do so. But, that aside, Warburton would reject (2) in part because he doesn't think it's possible for anyone to reasonably posit that you have an obligation that no one made obligatory, as noted above, but also he would deny you have any actual duties unless someone has obligated you to perform them. We can say that it's stupid not to do something, or it's bad taste not to do something; but Warburton's account of obligation, if accepted, applies to any kind of obligation. So on his account either we don't actually have much in the way of epistemic duties, or each one implies an authority capable of imposing general epistemic duties, which is an apparently divine legislative power.
Danaher does consider matters related to this. He argues that legislative signs are easy to fake; but, of course, this is true of laws, as well, and, again, this doesn't affect the obligatory character of laws. Even reasonable doubt about whether something is a law does not make it so that it's not a law for you.
But here's an interesting question: suppose the argument is sound. Does this cause a problem for DCT? For some versions perhaps. But while Warburton would reject the conclusion because he thinks moral obligations have universal scope, if the conclusion were right it wouldn't be a problem for the basic account of obligation. Warburton holds that when we talk about morality we talk about three different things -- good and bad taste, based on sentiment; good and bad sense, based on rational recognition of what is appropriate to what; and obligation and prohibition, based on authority. Why would anyone be bothered with whether atheists are obligated on such an account? When atheists claim they have a moral obligation, they can only do so on the basis of sentiment or reason, anyway. Warburton will simply say that things grounded on these are not actually obligations, and that treating them as if they were is incoherent, but the content itself will not be affected -- if incest is icky, it stays icky whether it is prohibited or not, and if helping someone in need is reasonable, it stays reasonable whether it is obligatory or not. So all the moral reasons atheists give can perfectly well be right; Warburton would just regard the talk of obligations as something that they are illicitly borrowing from theists. (It's worth comparing with Anscombe's article, "Modern Moral Philosophy", in this regard.) We can perfectly well make sense of some people having obligations that others don't; for instance, one of the reasons you might be given special obligations, is because you are given responsibilities or privileges others aren't. So the objection, even if sound, is not a direct problem for divine command theory as such, but for trying to combine DCT with universal moral obligations. It's true that it removes one apparent advantage of DCT over social relativism -- that it allows obligations of universal scope -- but it doesn't seem to affect anything else.
Various Links of Interest
* Nick Davis explains why professional psychiatric ethics needs the Goldwater Rule.
* Gracy Olmstead, How Jane Austen Proves that Prudence Is at the Heart of Happiness
* David Benton and Hayley Young look at the current science regarding losing weight.
* Sean Hermanson, Implicit Bias, Stereotype Threat, and Political Correctness in Philosophy
* The ideals of chivalry in the works of Bl. Ramon Llull
Katharine Burdekin, Swastika Night
Giambattista Vico, The New Science
Mary Astell, The Christian Religion, as Professed by a Daughter of the Church of England
Martha Nussbaum, The Fragility of Goodness