Imagine the following scenario:
SMITH: I know that evolution produced the biological world by naturalistic processes.
JONES: Interesting. Do you believe in God?
SMITH: No, I’m sure there’s no God.
JONES: How do you know that naturalistic evolution explains life as we see it?
SMITH: Because the evidence clearly demonstrates it.
JONES: Suppose there were no evidence for it. How would you handle that?
SMITH: What do you mean? There is evidence. Tons of it!
JONES: Of course there is. We both agree on that. I’d like to run a thought experiment with you, though, if you wouldn’t mind. It’s harmless, right? We’re talking about something we both know isn’t the case: a world where there was no evidence for naturalistic evolution.
SMITH: Sure, if you want to play thought-games, I’ll humor you.
JONES: Thanks. Now again, suppose we had Darwin’s outline of evolution, with no real evidence for it, except of course for the evidence he included in the book. How would you explain life as we see it?
SMITH: Well, I’d have to conclude there was some kind of evolutionary process, since life couldn’t have just sprung suddenly into all this complex variety. I think I’d be attracted to Darwin’s theory just on the strength of the idea, and the examples and evidence he wrote into The Origin of Species.
JONES: So if there was very little substantial evidence for evolution, you would probably be attracted to it anyway?
SMITH: Yes, because it makes so much sense.
JONES: You know that there’s controversy today over how the evidence in the natural world should be interpreted, and there are some people with genuine scientific credentials from genuine institutions of science who doubt that the Darwinian idea (or its successors) can successfully explain the evidence we have to work with.
SMITH: You spoke that very carefully, didn’t you? I was about to say that any so-called scientist who doubts evolution isn’t really a scientist after all, but you didn’t open the door for me to say that. Still, there are very few who disagree with evolution, and their alternate theory isn’t scientific.
JONES: What makes it so non-scientific?
SMITH: Other than the way they’re bucking such a huge scientific consensus, you mean?
JONES: I can’t believe you’d make that the point on which “being scientific” turns; you’d be calling Copernicus non-scientific.
SMITH: Well, sure, but here’s the other thing: they start with their theology and they move to their conclusions. That’s not science.
JONES: I suppose then you’d agree that if there’s some theory that has to be true just because the theology behind it requires it to be true, with or without evidence, that theory would have trouble being classified as scientific.
SMITH: Right! It’s a theological conclusion, not a scientific one.
JONES: But what if the people who held that theory said, “But look, we have evidence for our theory, too!”
SMITH: I’d be very suspicious. Theres’s hardly any such thing as pure evidence: it always requires interpretation. If you start out with a theory that derives from your theology, then any “evidence” you get for it is likely to be just a convenient interpretation, subject to all kinds of confirmation bias error.
JONES: Okay, I think you’re probably right about that. And do you suppose we could extend that to include not just “theology,” but any broad metaphysical beliefs about scientifically unreachable theories of reality?
SMITH: If it’s not scientific, it’s not scientific. So yes, I would extend it to any metaphysical theory.
JONES: Great, we’re still in agreement then. So again, if there’s some theory of life that has to be true just because some widely held metaphysical theory requires it to be true, that theory of life would have trouble being classified as being scientific; and if the people holding it said, “But look, we have evidence for our theory, too!” you’d be very suspicious of it. You’d think it was very likely their “evidence” had more to do with confirmation bias in their interpretation than with real science. Right?
SMITH: That’s right. So what’s your point?
JONES: If naturalism is true, could naturalistic evolution be false?
SMITH: Pardon me?
JONES: I said, if naturalism is true, could naturalistic evolution be false?
SMITH: Yes, I heard you, I just wasn’t expecting the question. Actually at this point I don’t think so. As Dawkins said, it took Darwin to make it possible to be an intellectually fulfilled atheist. It’s the only theory that works, based on naturalism.
JONES: But naturalism is a theory about the ultimate nature of reality: it’s a metaphysical theory. It’s a metaphysical theory that seems to require that evolution be true, with or without evidence. Based on what you’ve agreed to just now, doesn’t that start to make it sound like naturalistic evolution isn’t so scientific after all?
SMITH: But we have evidence for evolution, not just some metaphysical theory!
JONES: Didn’t we talk about that already? Didn’t you agree that if someone came up that answer, “you’d be very suspicious it had more to do with confirmation bias than with science”?
SMITH: But this is science! And evolution is FACT!
JONES: That’s what you say. It’s what a lot of scientists say, I know. It’s also the same thing you just described as looking very suspiciously like confirmation bias in action. And I have to wonder, doesn’t that fact bother you even a little bit? Doesn’t it bother you that you’ve reached the same conclusion with evidence—and your interpretation of that evidence—that you said you would have been “attracted to” with no evidence at all? Doesn’t it bother you to realize that you don’t need evidence to reach the conclusion you’ve reached?
SMITH: But again I tell you, this is science, and there is evidence!
JONES: Yes, yes. You said that before. Hey, I was just asking, okay?