Sigurd Jorsalfar pointed out that Stephen Law has a recent post related to this subject of more and less reasonable beliefs.

Beliefs can be more or less reasonable. There is, if you like, a scale of reasonableness on which beliefs may be located. Unfortunately, that reasonableness is a matter of degree is often overlooked. It’s sometimes assumed that if neither a belief A, nor its denial B, are conclusively “proved”, then the two beliefs must be more or less equally reasonable or unreasonable. As we will see, this assumption is false.

I suspect that happens more with discussions of theism and atheism than with any other kind of discussion, because it’s so damn convenient. We know that most theists don’t like being told that their beliefs aren’t very reasonable, so it’s nice to have reasons for not saying that. There are already reasons based on tact and the like, but they don’t apply to all situations. They don’t apply for instance to situations in which frank, open discussion is expected and taken for granted and freely engaged in. That’s probably why there’s so much obfuscation of the “better or worse reasons” aspect of the god/no god debates.

Of course, it’s contentious where some beliefs lie. Take belief in the existence of God, for example. Some consider belief God is no more reasonable than belief in fairies. Others believe it is fairly reasonable – at least as reasonable as, say, belief in extra-terrestrial intelligence. Those who claim to have had direct experience of God, or who think miracles and so on constitute fairly good evidence that God exists, may place belief fairly high up on the scale (even while acknowledging that their belief is not “proved”).

But they’ll be wrong.

Having set up the scale of reasonableness, let’s now look at a common mistake people make when assessing the reasonableness of a belief.

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Here’s a philosophical example. Even if we cannot conclusively prove either that God does exist or that he doesn’t, it doesn’t follow that the belief that God exists is just as reasonable or unreasonable as the belief that he doesn’t. It might still be the case that there are very good grounds for supposing God exists, and little reason to suppose he doesn’t. In which case it is far more reasonable to believe in God than it is to deny his existence. Conversely, there might be powerful evidence God doesn’t exist, and little reason to suppose he does. In which case atheism may be far more reasonable. We should not allow the fact that neither belief can be conclusively proved to obscure the fact that one belief might be far more reasonable than the other.

[We also, by the way, shouldn’t refer to “God” as “he” since that implies some knowledge about “God” that is also not reasonable to consider “knowledge.”]

[I altered the last sentence in the quoted passage, because there was what I think was a stray “not” in it that (of course) reversed the meaning. I reported the (I think) typo in a comment there.]

Unfortunately, theists sometimes respond to atheist arguments by pointing out the atheist has not conclusively proved there is no God, as if that showed belief in God must be fairly reasonable after all. Actually, even if the atheist can’t conclusively prove there is no God, they might still succeed in showing that belief in God is very unreasonable indeed – perhaps even as unreasonable as belief in fairies.

And by the same token, theists and accommodating atheists sometimes respond to atheist arguments by pointing out the atheist doesn’t know there is no god. As I said in the two sheds post, that’s true as far as it goes, but it doesn’t go all that far. The atheist has plenty of good reasons to think god doesn’t exist, and I don’t know of any good reasons to think god does exist. If there are good reasons to think god exists, please, somebody present them.