Think about the difference between the notion of the ‘powerful alien’ (a staple of science fiction) and the notion of a ‘god’ in a religion. What’s the essential difference between them? In the stories, they both do amazing, astonishing things. But a powerful alien is (ultimately, eventually) comprehensible – often in the story humans are able to figure out some way of duplicating its powers, or interfering with them, etc. Gods, though, are ’supernatural’: beyond what humans can do, and there’s no point in trying to figure out why or how they do what they do.

Think about the fact that once something’s understood, it’s not ’supernatural’ anymore. Think about all the things that have been confidently declared to be supernatural that have turned out to be perfectly explainable and comprehensible. Early in human history, practically everything was considered to be the direct result of supernatural forces, but over time more and more things have moved to the ‘explainable’ column. (BTW, it’s worth pointing out that so far as I can see, nothing has ever moved the other way, from the ‘explainable’ to the ’supernatural’ column…)

But how can we, in practice, distinguish between something ‘currently unknown but comprehensible’ and something ‘forever unknowable’? From a practical perspective, the only way to tell which category something falls into is to try to understand it; if you succeed, then it was knowable. The problem is, if you fail, you can’t conclude that it’s unknowable. It might be… but it also might be the case that you just didn’t happen to figure out something knowable, and you or someone else might have better luck on a subsequent attempt.

Accepting that there are things that we don’t know is not the same as accepting that there are things that we cannot, even in principle, know. As discussed above, the notion of ‘the unknowable’ adds nothing from a practical perspective. There is no way we can tell the difference between ’something we can never understand’ and ’something we can eventually understand but do not understand yet.’ We’ve seen plenty of cases where giving up on ever understanding something turned out to be unjustified.

So far as I can see, accepting the ’supernatural’ means, in effect, “I give up trying to understand this”.

Ummm… not quite exact. Scientific hypotheses need to be distinguishable from one another, and need to be competitively testable against each other.

Formally, Science relies on the validity of Wolfram’s Axiom (or other equivalents) for Inference via Propositional logic, the defined relation of Existential to Universal Quantification to extend to Predicate logic, the self-consistency of joint affirmation of the Zermelo-Fraenkel axioms (including Definition of the Empty Set, but independent of the Axiom of Choice), and the principle that Reality is Relatable to Evidence (synonymous with “experience”) with at most Recursively Enumerable formal complexity. Everything else (including the validity of the Experimental Method and the Principle of Cause-and-Effect) is inferences.

The problem with saying science is limited to “naturalistic” entities is that it necessitates defining non-naturalistic entitites. Such definitions may be either Recursively Enumerable complex, in which case science applies, or they require asserting existence of a Hypercomplex (or higher) relationship. Positing hypercomplexity appears to preclude any resolution of either Hume’s Problem of Induction or even Sextus Empiricus’s Problem of Deduction. Hypercomplexity mathematically precludes finite Recognition, so you can’t even tell it if it bites you on the backside.

I must not be a modernist, then. I do believe that effects usually have causes — I don’t understand vacuum fluctuation so I leave that open with “usually” — but I think emergence makes a “push-button” scheme insufficient for our understanding. I don’t believe that progress is inevitable and I don’t know anyone over the age of 20 who does; patriarchs and plutocrats have crushed progress many times throughout history and they may do so again before our species dies. I don’t think that human reason is infallible, rather, it is sufficient for survival in our evolutionary niche and that’s probably the best we can expect of it. Nor do correct ideas necessarily propagate; mental bulwarks like presuppositional apologetics serve emotional needs and as such may prove more popular than empiricism.

But I suspect that, using a heuristic developed by interviewing walking, talking modernists and listening to what they actually believe, rather than relying on an evangelical handbook’s ungenerous categorical definition, I’m probably still a modernist. I don’t see the label as being of much use, though, given that it’s a very poor tool for predicting any individual’s beliefs.

Ruse is more or less correct. The details are complicated but roughly speaking science can only talk about naturalistic entities because scientific hypotheses need to be falsifiable. It might help to read up on Karl Popper. Just because science can’t talk about something doesn’t mean that it doesn’t exist. Science is methodology, but it is a methodology that is by nature restricted to certain types of questions and answers.

The more serious problem that theists needs to deal with is that this method has worked so well. Methodological naturalism works really well. It is very hard to explain why methodological naturalism works well without recourse to some form of philosophical naturalism. But this is a distinct issue from what questions science can ask or what answers science can accept.