Start with this observation:
- Commonly used forms of fallacious reasoning are typically distortions of good forms of reasoning.
For instance, affirming the consequent is a distortion of the probabilistic fact that if we are sure that if p then q, then learning q is some evidence for p (unless q already had probability 1 or p had probability 0 or 1). The ad hominem fallacy of appeal to irrelevant features in an arguer is a distortion of a reasonable questioning of a person’s reliability on the basis of relevant features. Begging the question is, I suspect, a distortion of an appeal to the obviousness of the conclusion: “Murder is wrong. Look: it’s clear that it is!”
Now:
Wishful thinking is a commonly used form of fallacious reasoning.
So, wishful thinking is probably a distortion of a good form of reasoning.
I suppose one could think that wishful thinking is one of the exceptions to rule (1). But to be honest, I am far from sure there are any exceptions to rule (1), despite my cautious use of “typically”. And we should avoid positing exceptions to generally correct rules unless we have to.
So, if wishful thinking is a distortion of a good form of reasoning, what is that good form of reasoning?
My best answer is that wishful thinking is a distortion of correct probabilistic reasoning on the basis of the true claim that:
- Typically, things go right.
The distortion consists in the fact that in the fallacy of wishful thinking one is reasoning poorly, likely because one is doing one or more of the following:
confusing things going as one wishes them to go with things going right,
ignoring defeaters to the particular case, or
overestimating the typicality mentioned in (4).
Suppose I am right about (4) being true. Then the truth of (4) calls out for an explanation. I know of four potential explanations of (4):
Theism: God creates a good world.
Optimalism: everything is for the best.
Aristotelianism: rightness is a matter of lining up with the telos, and causal powers normally succeed at getting at what they are aiming at.
Statisticalism: norms are defined by what is typically the case.
I think (iv) is untenable, so that leaves (i)-(iii).
Now, optimalism gives strong evidence for theism. First, theism would provide an excellent explanation for optimalism (Leibniz). Second, if optimalism is true, then there is a God, because that’s for the best (Rescher).
Aristotelianism also provides evidence for theism, because it is difficult to explain naturalistically where teleology comes from.
So, thinking through the fallacy of wishful thinking provides some evidence for theism.