Define moral realism as the claim there are objective moral truths and that we know some of them. Consider the argument:

  1. If no religious beliefs are true, moral realism is false.
  2. Moral realism is true.
  3. So, some religious beliefs are true.
I won't argue for (2), but only for (1). For my argument I will assume a form of reliabilism. (I think the arguments here work well to establish (1) on non-reliabilist epistemologies. The present argument plugs the weakness of that argument.)

Here is the line of thought. Start with this plausible observation:

  1. If no religious beliefs are true, the correct explanation of our moral beliefs is that moral beliefs were beliefs about unobservable realities that evolved to help prevent defection in prisoner's dilemmas in cognitively sophisticated hominids.

Now, if reliabilism is true, the question is whether the process, P, of evolutionarily forming beliefs about unobservable realities to help prevent defection in prisoner's dilemmas is reliable: is likely to produce true belief. But now observe that if no religious beliefs are true, very likely our religious beliefs also arose out of P . Positing supernatural judges who can see if one is sneakily defecting in prisoner's dilemmas is obviously quite helpful. Thus, we have two families of beliefs produced by P: moral and religious. If the religious ones are all false, the process is unreliable. If the process is unreliable, then its outputs are not knowledge. And so if no religious beliefs are true, we have no moral knowledge, and hence moral realism is false.

Of course, we have the usual tricky thing with reliabilism: What is the relevant level of description of the belief-forming process? Is it: "evolutionarily forming beliefs about unobservable realities to help prevent defection in prisoner's dilemmas", or is it something narrower that is special to the moral case, and not present in the religious case? I think it would be difficult, however, to formulate a description narrowed to the moral case without being completely ad hoc.

Many people believe that there is: 1) no greatest number, 2) no greatest possible world, and 3) a greatest being (person, agent). The reason many people believe 1 and 2 is that there seems to be procedures to take a number (or world) and return a larger (or better) one. For any number (cardinal), take the powerset to get a larger number. For any world, stick some happy people in a far off corner to get a better world. (Of course, there is far from universal agreement on this second point.) The question arises: Is there any way to take a being, and return a better one?

One way is to try and link beings with the worlds they create. The idea would be that a being who creates a surpassable world is a surpassable being. This line of thought gives rise to a whole body of literature, some quite recent. Going in a different direction, here is another way that any being might be surpassable. Let us imagine that some virtues, e.g. courage, are traits wherein one wants to be at the mean that lies between extremes. We might imagine that 'courage-level' runs along a continuum from 0 (totally cowardly) to 1 (totally rash). Then, speaking loosely, somewhere in the middle is best. But, is it clear that any specific point is best? That is, what if the function, F, from courage-level (which runs from 0 to 1) to the value or goodness of the being goes as follows: F(x) = x for x in [0, 0.5] and F(x) = 1.01 - x for x in (0.5, 1]. Then there is no greatest being, as for any being, there is a better one. There is no greatest being, as beings get better as they approach 0.5 from the right on courage-level.

If there is an optimal point on a trait, call that trait 'closed'. If there is not an optimal point on a trait (for any level a being takes on the trait, there is a better level), as in the courage example above, call that trait 'open'. The question is, are all traits are closed? Or, what is the best argument to the conclusion that all traits are closed? In the absence of an argument regarding open and closed traits, the principle of indifference might suggest that courage is open with 50% probability and closed with 50% probability.

(One way to respond is to argue along these lines: certain traits/properties are fundamental (e.g., power, knowledge, freedom, goodness), these traits take maximal levels (individually and together), all other traits follow logically from these, and thus all traits take optimal levels and so are closed. Is there a relatively simple and convincing argument along these lines? Also, are there other ways to argue that all traits are closed? In particular, and thinking of approaching the question from a non-theistic angle, am I missing some sort of simple argument or reason as to why all traits are closed?)

Let Contingentism be the thesis that no concrete thing must exist. Define 'concrete thing' as anything that can cause something, or leave it as primitive. (Side note: Contingentism is hotly debated among philosophers of religion. But surely it is a thesis of metaphysics; so why aren't metaphysicians debating this?)

Arguments against Contingentism typically take the following form:
1. Every fact of type T has an explanation (else: is explicable)
2. If Contingentism is true, then there is a fact of type T that has no explanation (else: is not explicable)
3. Contingentism is not true.

Committed Contingentists usually either end up denying the principle of explanation employed by (1) or withholding judgment. After all, such explanatory principles tend to be very far-reaching.

But here's another strategy. We count costs. Rather than searching for sound philosophical arguments for/against Contignentism, we identify costs and benefits of Contingentism. That may be a lot easier. And it can help us make progress without having to make converts: for a committed contingentist can, in principle, come to agree that there are certain costs of Contingentism.

I'm going to propose one cost--to get this strategy started. (I do not claim this is the most serious cost, or that there aren't counter-costs that ultimately outweigh it.)


In The Second-Person Standpoint, Stephen Darwall notes the fact that "we speak of being grateful for good weather" as a possible objection to his view that reactive attitudes are 'second-personal'. He goes on to dismiss the objection on grounds that such gratitude "evidently involves the conceit that the weather is a free gift, as if from God" (p. 73). This remark struck me because I have known people who feel a sort of psychological need to believe in God in order to have someone to be grateful to (or, in other cases, angry at) for events beyond human (or animal, or presumably space alien) control. At first glance, it certainly appears (to me, at least) that belief based on this kind of psychological need would be irrational. Perhaps, however, the matter is not so simple. Consider the following argument:

  1. Human beings are so constituted as to generally feel reactive attitudes in appropriate circumstances.

  2. Many human beings feel reactive attitudes about, e.g., the weather.

  3. Therefore,
  4. It is appropriate to feel reactive attitudes about the weather (inductively, from 1 and 2).

  5. It is only appropriate to feel reactive attitudes about events which are actions of some agent.

  6. Therefore,
  7. Weather events are actions of some agent (from 3 and 4).

A lot of moral theories seem to be committed to (1). (2) is empirically verified. The strength of the inductive inference will depend on how reliable our tendencies to feel reactive attitudes in appropriate circumstances are, and also on how common it is to feel reactive attitudes about the weather (and other similar things). So that might be a weak point. (4) is pretty widely held and intuitively plausible, and (5) follows deductively from (3) and (4).

Personally, I think the kind of reliability we have in (1) is pretty limited (we get things wrong a lot), so I don't think the argument is very compelling. Still, it does seem that there might be people whose epistemic situation is such that their credence in the existence of God can be justifiably boosted by an argument along these lines.