Over the last fifteen or so years, Paul Copan has written a variety of articles, chapters, and books which argue against ethics without God. (To be precise, Copan argues against atheistic or naturalistic metaethics.) As I interpret him, Copan offers several independent arguments against ethics without God. I call one of those arguments “Copan’s Noseeum Moral Argument” and that is the argument I want to discuss here.
The basic idea of the argument is this. since we see no ontological foundation for objective moral values in a naturalistic universe, there are no objective moral values in a naturalistic universe. This argument is highly similar to one of William Rowe’s evidential arguments from evil, according to which our failure to see an outweighing good for every evil in the world is evidence that there is no such outweighing good and hence that God does not exist. Just as Stephen Wykstra has labeled Rowe’s argument “Rowe’s Noseeum Argument from Evil,” I shall call Copan’s moral argument “Copan’s Noseeum Moral Argument.” Copan writes this:
What is it within [an atheist’s] worldview that furnishes us with such an ontology or metaphysic of personhood as being of intrinsic value or worth? Nothing, so far as I can see.
I simply do not see that his worldview has the ontological resources to bring about this remarkable transformation [of moral value].
What we have, then, is the following inference:
P. We see no ontological foundation for objective moral values in a naturalistic world; so, it is quite probable that
Q. There is no ontological foundation at all for objective moral values in a naturalistic world.
Copan’s argument contains an implicit premise that objective moral values (OMVs) exist. Copan’s argument also seems (?) to implicitly assume that if OMVs exist, then they must have an ontological foundation. Let’s call this assumption “OF.”
Copan seems to suggest that the combination of Q and OF entail that there are no OMVs in a naturalistic world. In his words, “the atheistic worldview lacks such [ontological] resources.” In contrast, he says, theism provides the necessary ontological foundation for OMVs and hence OF is true. Hence, on Copan’s view, OMVs are much more probable given theism than given naturalism and, hence, any evidence for OMVs is also evidence for theism and against naturalism.
It seems to me there are at least two problems with that inference. First, it’s far from obvious that OF is true. On the assumption that OMVs exist, it ‘s possible that OMVs exist without any ontological foundation. At least, it’s not obvious that it’s impossible. If Copan has an argument against that possibility, he hasn’t told us what it is.
Second, the inference from P to Q is justified only if we have no good reason to be in doubt about whether, if there is an ontological foundation for ethical truths, we would quite likely see that foundation. Assume that metaphysical naturalism is true, OMVs exist, and OMVs have an ontological foundation. In that scenario, why should we believe that it’s more likely than not that humans would have discovered by now the ontological foundation for OMVs? Perhaps the foundation is simply elusive or inscrutable. Again, if Copan has an argument here, he hasn’t told us what it is.
In fairness to Copan, I want to end by mentioning two points. First, Copan nowhere formally presents the argument I have called the “Noseeum Argument.” This is a reconstruction of that argument, based upon an interpretation of one of his essays. Copan may or may not agree that he, in fact, offered the argument I just attributed to him. (As an aside, in the interest of clarity, I wish Copan would explicitly state the logical form of his arguments in his writings.)
Second, even if my interpretation is correct and Copan did make a “noseeum argument,” Copan also defends many other arguments against ethics without God. The argument I’ve considered here is probably the weakest of the bunch, so it would be a mistake to judge Copan’s total case based upon this one argument.
 Stephen John Wykstra, “Rowe’s Noseeum Arguments from Evil” The Evidential Argument from Evil (ed. Daniel Howard-Snyder, Indianapolis: Indiana University Press, 1996), 126.
 Paul Copan, “Can Michael Martin Be A Moral Realist?: Sic et Non,” Philosophia Christi, Series 2, 1/2 (1999): 45-72 at 50. Italics are mine.
 Copan 1999, 54. Italics are mine. See also the reference to “no obvious [ontological] resources” on p. 56.
 Copan 1999, 61.
 Copan 1999, 56.