In response to a post by Victor Reppert, I left the following comments on his blog.

Victor — I’m very late to this thread, but I hope you’ll respond to this comment.
I read the linked article. Maybe I misunderstood it, but it seems to me that even if everything that article said were correct, it wouldn’t follow that materialism cannot explain beauty. What that article talked about is one recent attempt by neuroscientists to offer a (neuro-)scientific explanation for beauty, an attempt which apparently didn’t work out very well. Have I missed something?
I don’t identify as a materialist because I understand materialism to be logically incompatible with abstract objects. Since I deny the existence of supernatural beings but allow for the existence of abstract objects, I identify as a metaphysical naturalist.
I’m aware that some philosophers (including Swinburne) have argued that beauty is evidence favoring theism over atheism (or naturalism). While I can usually understand why theists find various theistic arguments convincing, that’s not the case with the argument from beauty. I am baffled why anyone finds *that* theistic argument convincing.
In my experience, defenders of arguments from beauty usually (1) conflate the existence of beauty with the existence of observers who can appreciate beauty; and (2) assume without argument that the concept of “objective beauty” is coherent. I, for one, find the concept of “objective beauty” to be unintelligible. And if beauty is not objective, then beauty does not favor theism, since evolutionary naturalism can explain beauty, including non-utilitarian beauty, as well as theism. (As TaiChi has pointed out, not every inherited trait need be adaptive.) If, on the other hand, beauty is objective, then it’s far from clear why theism is a better explanation for non-utilitarian beauty than, say, neo-Platonism about beauty.