I'm with you that, if you don't close the loop via experiment, you don't have science. But you have to be careful that you not go too far, and say that science is the only way we can know truth. Logical positivism is dead for a reason. (Actually, for several reasons.)
I don't disagree with Myth #3, but I had a hard time getting to it after reading Myth #2:
The scientific method assumes naturalism/materialism/atheism... This is false. The scientific method contains no assumptions whatsoever. The scientific method is simply that: a method.
I don't think that's a good way to put it. There is an assumption that this method is a valid, useful, good thing to do. A souffle recipe presupposes that you want a souffle, or you wouldn't be reading it.
The scientific method hints ambiguously at epistemological commitments, and that ambiguity is not a point in its favor. Different people make those assumptions tacitly and don't realize that they disagree with each other, and don't even apply them consistently to themselves.
I also happen to agree that the scientific method has some kind of epistemic benefit, especially as compared to the potential alternatives. But those benefits prove maddeningly difficult to nail down. The epistemic commitments always turn out to be too loose (admitting pseudosciences) or too strict (rejecting sciences that resist the kinds of experiments you'd like to do).
You could. It says "First, science never proves anything; instead it produces explanations of observations." but science doesn't have to explain an observation. There are tons of times when science tells us what we'll observe under certain conditions while never giving us an explanation for how/why it works out that way. An explanation is the ideal, but all science needs is to give us something we can reasonably predict to be useful.
> There is an assumption that this method is a valid, useful, good thing to do.
No, that is not an assumption. That is an observation. The scientific method produces theories with predictive power, and it does this better than any other known method. That is an empirical fact, not an assumption. This is the reason science is a thing.
Science has not proven that the observation will continue to hold. It happens to have worked so far, but you cannot prove that it will continue to.
You're applying the scientific method to itself, making a large-scale inference from limited data. This is precisely the grounds on which the Logical Positivists realized that they couldn't achieve their ends of putting science on a sound scientific footing.
All facts are provisional. If a validating observation does not continue to hold, that is another observational fact. At some point of replication and sigmas, it becomes another Problem, to be fed back into the scientific meat grinder.
For example, maybe vague observations of Mercury were consistent with Newton. But eventually, telescopes improved, duration of accurate records extended, many good instruments were deployed around the world. Then it became a Problem. Also note that Einstein fitted GR to Mercury, so he could not predict it as independent confirmation. It took the Eddington observation of light bending near the sun, during a solar eclipse, to provide the first evidence (even that was weak, and fixed, but the fix was on the right side of history :)
> Science has not proven that the observation will continue to hold. It happens to have worked so far, but you cannot prove that it will continue to.
Yes, that's true. So?
> You're applying the scientific method to itself
Yes, that's true too.
> This is precisely the grounds on which the Logical Positivists realized that they couldn't achieve their ends of putting science on a sound scientific footing.
Maybe, but I'm not making any claims about knowledge. The only claim I'm making is about effectiveness and that's an empirical claim. not a philosophical one. One can go on to hypothesize that science is effective because it is "true" (whatever that means). That seems plausible to me (for some reasonable definition of "true") but it's still just another hypothesis.
