In a recent discussion of steelmanning, I observed that few people around here seem interested in steelmanning young earth creationism. In the resulting subthread, someone suggested Yvain's steelman of the Time Cube as illustrating what a steelman of of young earth creationism might look like. But steelmanning the Time Cube may be too much of a stretch, it's a little too incoherent to steelman effectively without changing it into something else entirely. In contrast, once I thought about it it wasn't hard to come up with some ways to steelman young earth creationism in a way that was very much in keeping with the spirit of real young earth creationist writings.
The way to do it, I think, is to approach it from a philosophy of science angle. For example, here's a quote from an article titled "Creation: 'Where's the Proof?'" on Answers in Genesis, a website run by young earth creationist Ken Ham (who recently debated science guy Bill Nye):
Creationists and evolutionists, Christians and non-Christians all have the same evidence—the same facts. Think about it: we all have the same earth, the same fossil layers, the same animals and plants, the same stars—the facts are all the same.
The difference is in the way we all interpret the facts. And why do we interpret facts differently? Because we start with different presuppositions. These are things that are assumed to be true, without being able to prove them. These then become the basis for other conclusions. All reasoning is based on presuppositions (also called axioms). This becomes especially relevant when dealing with past events.
You find a lot of this kind of thing on Answers in Genesis. For example, they're willing to concede that on certain assumptions, radiometric dating is a strong argument that the earth is a lot more than 10,000 years old, but they deny that they need to accept those assumptions.
I honestly don't think it's much of a stretch to steelman this into something that would look a lot like some of the things the philosophers of science I studied in graduate school said. I started writing a long post spelling this out, but then I started worrying I was going too far in playing devil's advocacy for creationism (even for an exercise in exploring the weaknesses of steelmanning). So instead, I'll just mention some places too look for material in such a project: The Duhem-Quine thesis, confirmation holism, underdetermination of scientific theory. Fun fact: Pierre Duhem regarded the existence of atoms as a metaphysical question that could not be settled by experiment, and this has not stopped him from being regarded as an important contributor to philosophy of science. I suppose Feyerabend belongs on the list too, but that's almost too easy (even though, yes, I did have to study Feyerabend in grad school).
Oh, and I could even find material for my steelmanning of young earth creationism in the writings of Robert Pennock, a philosopher of science who testified against Intelligent Design at the Dover trial. Some philosophers, while thinking creationism is dead wrong, have criticized the reasoning used in that and other court decisions that have kept anti-evolutionism out of public schools in the US. Pennock wrote a response, titled "Can’t philosophers tell the difference between science and religion?" where he argued, among other things, that methodological naturalism (MN) is essential to science and supernatural claims are inherently untestable. A relevant quote:
The second misunderstanding arises in a different way, with ID proponents and even some opponents... claiming that science can indeed test the supernatural... For instance, both Laudan and Quinn cite the young-earth creationist view that God created the earth is 6,000 to 10,000 years ago as a hypothesis that is testable and found to be false. But this and other examples that are offered to show the possibility of tests of the supernatural invariably build in naturalistic assumptions that creationists do not share... The point here is that we cannot overlook or ignore, as Laudan and company regularly do, the fact that creationists have a fundamentally different notion from science of what constitutes proper evidential grounds for warranted belief. The young earth view is certainly disconfirmed if we are considering matters under MN, but if one takes the supernatural aspect of the claim seriously, then one loses any ground upon which to test the claim.
So on Pennock's view, testing young-earth creationism and thereby demonstrating it to be false is not possible without relying on naturalistic assumptions. This creates an opening for the creationist to question whether science needs to rely on naturalistic assumptions, and argue that one could create an equally valid version of science based on (fundamentalist) Christian assumptions.
You might conclude Pennock is wrong about this, and young-earth creationism really has been straightforwardly refuted by science, but this creates a different opening for the creationist: argue that if Pennock is wrong, his ideas really shouldn't be the basis of court decisions about whether creationism can be taught in public schools. Evolutionists could respond by arguing for some other philosophical basis for rejecting creationism, but then they'd probably have to make some contentious philosophical claims and we shouldn't be determining what children can learn based on contentious philosophical claims either.
An argument along the above lines could also be used for a different purpose, by someone who rejected creationism but wanted to make a show of being fair-minded towards their opponents and generally more rational than most of their peers. The thing to do is to say that while young earth creationism can be decisively refuted, most scientists and philosophers botch the philosophy required to do that, and this indicates their rejection of creationism is mostly tribalistic, and the young-earth creationists don't actually come out looking so bad by comparison.
Speaking as Chris Hallquist and not some hypothetical alter-ego, I think that if a philosophy of science makes young earth creationism come out looking good, that's a reductio for that philosophy. I think educated people who reject young earth creationism are generally rational to do so, even if their philosophy isn't that hot. Still, I'd be curious to know what else people on LessWrong can come up with in the way of steelmanning young earth creationism.