All that is to say I hold Chesterton up to a higher standard of whether or not I agree with him — I want something I can use in debate. In what you’ve presented he doesn’t give me much.

I dunno, seems to me no different than the standard presupper argument of “your strict materialism cuts its own throat by denying you the use of logic itself,” which I’ve seen in plenty of debates. The only reason the argument is not effective is because atheists don’t seem to understand it, not that they stipulate it and don’t care.

Chesterton: But if [evolution] means anything more, it means that there is no such thing as an ape to change, and no such thing as a man for him to change into.

forester: If species are always in flux, then the term “species” is illusive to the point of unreality. Ultimately there is no such thing as a species; there are only organisms, some of which can reproduce with others.

I think you subtly miss Chesterton’s point; if you look at the parts I boldened, “It means that there is no such thing as a thing. At best, there is only one thing, and that is a flux of everything and anything,” it seemed to me that what he was saying was more along the lines of, “if strong materialism/naturalism is true, then there exists nothing so meaningful as “an ape” or “a man” or any thing. So he goes beyond “there are only organisms, some of which can reproduce with each other” to “there is only a dynamic collection of matter and energy”

Chesterton: Now as a matter of fact, there is a not a shadow of evidence that this thing [the human mind] was evolved at all.

forester: I hope Chesterton fleshes out this assertion in his book.

Sadly, no.

As it appears here, he seems to neglect actual evolutionary arguments….The trend seems clear: an increasing sophistication of human thought.

But Chesterton’s statement is not directed at progress from cave paintings to now; he is asserting that the cave paintings came out of nowhere; or more specifically, that the human mind that the evidence did not gradually appear, but suddenly appeared.

I’ve never understood what justification Darwinists use for assuming cave paintings are in any way different from underpass graffiti. Any lout can crawl into a dark space and leave his mark. Just because one individual — or even one small community — did so doesn’t make that the high mark of civilizations at that point in time.

Chesterton accuses the Darwinists of missing the caveman for the caves, as it were. He redirects us away from the qualitative nature of the cave paintings (are they primitive, are they good art, are they indicative of sophisticated culture/civilization), and towards the quantitative nature: they mark the existence of abstract, imaginative thought which is radically different than anything in the animal kingdom. As you say, “any lout can crawl into a dark space and leave his mark,” but no monkey would ever! From the middle of Ch. 1 of Everlasting Man:

That is the simplest lesson to learn in the cavern of the colored pictures; only it is too simple to be learnt. It is the simple truth that man does differ from the brutes in kind and not in degree; and the proof of it is here; that it sounds like a truism to say that the most primitive man drew a picture of a monkey and that it sounds like a joke to say that the most intelligent monkey drew a picture of a man. Something of division and disproportion has appeared; and it is unique. Art is the signature of man.