Criticism of William Lane Craig's Moral Argument For God

In his debate with Sam Harris, William Lane Craig makes the following argument:

1. If god does not exist, then objective moral values and duties do not exist.
2. Objective moral values do exist.
3. Therefore, god exists.

The argument seems simple enough. It consists of two premises and is in the valid logical form known as modus tollens. If we are logical, then we must accept his conclusion if we accept his premises. Fortunately, there is no compelling reason to accept either one of them.

The first premise hinges on the idea that only a fixed and unchanging objective creator can instill reality with an objective morality. Craig emphasizes that this is an ontological claim rather than an epistemological one. The difference is that the former only asserts the existence of this kind of morality whereas the latter would be a claim of what we can know about said morality. Craig very carefully chooses his language so that his argument is purely ontological; he makes no attempt to claim that there is any way for us to know what his proposed form of morality entails. 

This raises an important question: why would god create an objective moral standard (an ideal by which to live) but not grant us humans any objective means to access it? There are two ways that Craig can resolve this. The first would be to claim (as he actually does) that the abstract god whose existence he and Sam Harris debated can be specified to be the god of Abraham and the Bible. Moreover, Craig would have to argue that the Bible or perhaps the Holy Spirit or some other variation of Christian mysticism is god's way of granting humans access to the objective moral code. This obviously doesn't work because these "methods" of accessing the code have been available for centuries and yet there are almost as many interpretations of the code as there are humans interpreting it. Am I too believe that god could not devise a method of accessing his own moral code in an unambiguous way? Mathematicians and programmers have no problem writing unambiguous instructions, yet god does? The second way in which Craig can deflect this is to simply say that this is irrelevant to his claim. God simply created the objective moral code, but is under no obligation to reveal it to his creations. That's fine, but then Craig must admit that his argument implies that morality is inherently unknowable. 

Now let's approach the first premise sanely. Let's say we have the set of all objective moral values, laws, and duties, called OM. Additionally, say we have some law L that is in the set OM. The main disagreement in the debate is what makes L objectively good. In Craig's version of OM, L is objectively good simply on the basis that it is in OM, and OM was compiled by god. In Harris's version of OM, L is objectively good because it minimizes suffering and maximizes pleasure; I'll call this "L is morally optimized". 

Craig's objection then is: what is objectively good about being morally optimized? In other words, what is good about minimizing suffering and maximizing pain? If we want L to be morally optimized, then we assume that there already is some moral standard against which to optimize L. Since there is a morality more fundamental than Harris's OM, his OM can at best just be a subset of a true and more basic OM, thus his OM is not objective. What Craig fails to realize, is that the same objection can be raised against his OM. Namely, what is objectively good about L being chosen by god? Is L good because god chose it, or did god choose it because it is inherently good? If the latter is the case, then Craig's OM suffers from the same defects as Harris's. If it's the former, then there are even more issues raised. If god chose all L in OM, then that implies that he could have chosen otherwise, therefore god's OM isn't objective (similarly, the natural numbers are objective because it's provably impossible to pick them differently). Put another way, if he could have picked otherwise, then there's nothing 'objective' about it.

To summarize, it now seems apparent that god's existence and the existence of objective morality are independent of one another. The argument used to show this can be somewhat generalized to show that absolutely no moral framework is objective. Let's show this by contradiction. Assume OM' is the most fundamental and objective moral system and L is an arbitrary law of that system. One can then ask, why is L in OM'? There are two possible responses:

1. There exists some formal decision process, D(x), such that on any arbitrary moral question x, D says whether x is moral or not. For example, D("is child abuse good?") = no, D("is feeding the poor good?") = yes. Thus, OM' is the set of all moral values v such that D(v) = yes. 
2. It just is.

If we assume (1), then we can always ask why does D produce laws that are good? What is objectively good about the laws that D produces? On the one hand we can say that D is good because D says so, i.e., D("are the values that D says yes to good?") = yes, but this would be trivially circular and would not be a satisfying answer. On the other hand we can say that D decides its answers based on some more fundamental morality, but this would contradict our initial assumption. Ergo, we can conclude that (1) is not a legitimate response. 

The only other response is (2), which may not seem like much of a response, but it actually carries more weight than (1). If you think about it, what is 'objectivity' other than something that "just is"? The natural numbers are objective because they follow from a small set of axioms; they simply are. However, this sort of reasoning makes little sense when it comes to questions like "what is good?" This is because if you say something is good just because it is, you can continue to ask "why?" and still make sense. Whereas you can't reasonably have this same regress of whys about the natural numbers; they actually just are. The axioms that they arise from (the Peano Axioms for those interested), constrain them into existence, and the natural numbers manifest naturally as their consequences. It would make no sense to ask "why?" because we know why: the rules of logic joined with the Peano Axioms force the natural numbers to exist, and no other set of entities could have taken their place, hence they are objective. 

Thus, if assume the existence of an objective morality OM', we are lead either into direct contradiction or a contradiction via infinite regress. In either case, we can conclude that Craig's second and last premise is also unfounded.

Despite what I wrote about Harris's moral philosophy above, I don't want to leave the reader with the impression that his moral system is just as bad as Craig's. In terms of my general argument against moral objectivity above, Craig's OM suffers by assuming response (2), and Harris's OM suffers by assuming (1). Harris's moral system (which he outlines in The Moral Landscape) is superior for the following reasons. As already stated, Harris's OM assumes response (1), which means that there is some decision process D that determines whether something is moral or not. For Harris's OM, this D is based on socially-evolved traits, namely mutual cooperation and empathy. Things are 'good' because they minimize suffering and maximize pleasure; they benefit the species as a whole. While this decision process doesn't yield objectively good values (and in fact it can't be as per my argument above), but at least it's not arbitrary, and is in some sense universal. Furthermore, Harris's OM gives us a perfectly reasonable way by which to know it: science, the best tool with which to know anything at all. 

Although Sam Harris can never conclude that his moral system is objective, there are plenty of arguments to be made for why his system is a good one in general (need it be objective to be useful?). My conjecture is that it's probably the best system of morality that's devisable, at least in terms of fairness. If you're interested in the full debate, it can be found here: