This piece was originally published on AlterNet.

Note: I am now, once again, re-thinking this question, and am planning to write more about it soon. I think that I'm still basically standing by my position, which is that atheism both can and should be falsifiable. But I am reconsidering the question of what the word "god" even means, and whether the term can be defined in a way that is both coherent and non-trivial. So this piece is not my final word on the subject: it's still a work in progress.

Is there any possible evidence that would persuade atheists out of our atheism?

And if not -- does that make our atheism close-minded and dogmatic?

There's been an interesting debate lately in the atheist blogosphere. (The media will no doubt point to it as a sign of a terrible schism in the so-called New Atheist movement; but really, it's been a very friendly and civil conversation so far, among people who are fundamentally allies.) The debate revolves around whether there's any possible evidence that could convince atheists to change their minds... and if not, whether that makes their atheism an unshakable article of faith rather than a reasonable, evidence-based conclusion.



PZ Myers, of the famed Pharyngula blog (almost certainly the most widely-read of all atheist blogs), recently asserted that he had made up his mind. The case for atheism was just too devastating, and at this point, no possible evidence could ever convince him that any religion was correct. Jerry Coyne (author of Why Evolution Is True, the book and the blog) has expressed strong disagreement. He thinks atheism is falsifiable -- and he thinks that it should be. If there is no possible evidence that would convince us God was real, he argues, not even the most wildly ludicrous hypothetical chain of events you could dream up, then atheists really would be just as close-minded as believers claim. The debate between Coyne and Myers has extended its tendrils throughout the atheist blogosphere... so I'm getting in on the action.

I've written at length about how atheism is, and should be, falsifiable. I've even gone out on a limb, in this very blog, about what exact evidence would persuade me that God was real. And after reading Myers and Coyne and a whole lot of other atheists in this debate, and after thinking about it at some length, I've reached two conclusions:

1) I don't agree with PZ.

2) I think PZ makes some seriously important points.

I don't ultimately agree with him, but the questions he raises are making me re-think my position on this question.



Let's get the first bit out of the way: I think PZ is wrong. It seems, uncharacteristically for him, like he's not getting the rules of the game. I think he's focusing too much on existing religions, gods that people currently believe in, and on whether any of those could ever provide any evidence that would persuade him. Yes, atheists pretty much agree that no existing religion has a shred of decent evidence to support it. That's why we're atheists. If we thought any religion had supported itself with decent evidence, we'd accept that religion. That's not the game. The game isn't, "What religion that currently exists could convince you that it was right?" The game is, "What hypothetical made-up religion could convince you that it was right?"

Or, to put it another way: We're talking counter-factuals. We understand that the universe, as it is now, is overwhelming in its evidence for atheism and materialism, and against any kind of deity or supernatural realm. We get that. We're talking about alternative universes. We're asking, "What would the world look like if there were a god or gods?"



And, in pointing out how vastly different that world would be from the one we actually live in, we're not just making a stronger argument for our position. We're not even just making our position falsifiable, and thus making it philosophically stronger. We're making our position rhetorically stronger. In my debates with religious believers, I've found the "What would convince you that you were mistaken?" gun to be invaluable. When I can point out that I'm willing to consider the evidence for religion, but that no possible evidence could convince them that they were mistaken -- and that they therefore aren't arguing in good faith -- it can be very effective in getting believers to re-examine their beliefs. And it shuts down the "It's so close-minded of you to come to a provisional conclusion about religion based on the best available evidence" canard very effectively.

So it's frustrating to see one of the most prominent atheists undercut that tactic, and give the "Atheists are close-minded" brigade ammunition. (I don't think the PR point is the most important one -- if I were persuaded that PZ's position was philosophically sound, I'd stand by it even if it made atheists look bad and made our debates harder -- but since I think that philosophical soundness and good PR do dovetail in this case, I think the PR angle is worth pointing out.)

But PZ makes some important points here. In thinking over my disagreement with him, I've had to seriously re-think my own position on this question.

And I think the most important point he makes is this:

Religion has to do more than come up with some good evidence for its hypothesis.

It has to come up with a coherent hypothesis in the first place.

And thus far, religion has completely failed to do this.

Religions haven't just failed to support their assorted hypotheses with good, solid, carefully gathered, rigorously tested evidence. They've failed to come up with hypotheses that are even worth subjecting to testing. They've failed to come up with hypotheses that are worth the paper they're printed on.



Religions are notorious for vague definitions, unfalsifiable hypotheses, slippery arguments, shoddy excuses for why their supporting evidence is so crummy, and the incessant moving of goalposts. Many theologies are logically contradictory on the face of it -- the Trinity, for instance, or an all-powerful/ all-knowing/ all-good God who nevertheless permits and even creates evil and suffering -- and while entire books are filled with attempts to explain these contradictions, the conclusions always boil down to, "It's a mystery." And the so-called "sophisticated modern theologies" define God so vaguely that you can't reach any conclusions about what he's like, or what he would and wouldn't do, or how a world with him in it would be any different than a world without him. They define God so abstractly that he might as well not exist. (Either that, or they actually do define God as having specific effects on the world, such as interventions in the process of evolution -- effects that we have no reason whatsoever to think are real, and every reason to think are bunk.)

And when I ask religious believers who aren't theologians to define what exactly they believe, they almost always evade the question. They point to the existence of "sophisticated modern theology," without actually explaining what any of this theology says, much less why they believe it. They resort to vagueness, equivocation, excuses for why they shouldn't have to answer the question. In some cases, they get outright hostile at my unmitigated temerity to ask.



Even when religions do make falsifiable claims -- like "Prayer is effective in treating illness" or "The world was created 6,000 years ago" -- their defenders slip and slide and squirm away when their claims actually do get falsified. They find the most convoluted rationalizations for why the evidence doesn't count... or they just stick their fingers in their ears and ignore the evidence altogether. The beliefs are falsifiable in theory -- but in practice, they're unshakeable articles of faith.

So in order to persuade me that it was probably true, a religion would have to do more than just provide some decent evidence for its hypothesis. It would have to provide a decent hypothesis in the first place. It would have to provide a hypothesis that explains existing evidence, makes accurate predictions about future events, can be tested, can have those tests replicated, is consistent with what we already know (or provides a better explanation for it than existing theories), and is internally consistent.

What's more: This hypothesis would have to do more than just explain whatever new evidence might appear to support it.

It would have to explain the utter lack of good supporting evidence in the past.

It would have to explain why, in thousands and thousands and thousands of years of human history, supernatural explanations of unexplained phenomena have never once panned out... and a natural explanation has always, always, always turned out to be right.



This is another hugely important point that PZ, along with others defending his position, has been making in these debates. Atheists aren't just atheists because we don't see any good evidence here and now for the God hypothesis. We're atheists because, in all of human history, there has never once been any good evidence for the God hypothesis. We're atheists because, as Julia Sweeney said in Letting Go of God, "The world behaves exactly as you would expect it would, if there were no Supreme Being, no Supreme Consciousness, and no supernatural." The world behaves that way -- and it always has. We're atheists because, every time in history that we've come to a better understanding about the world, that understanding has always been one of physical cause and effect. We're atheists because claims from the past about miracles and so on have always come from unreliable sources, and have never once been substantiated. We're atheists because, over the decades and centuries and millennia, religions have risen and fallen, not because they've been better supported with good evidence, but for social and psychological and political reasons, entirely consistent with them being entirely made up. We're atheists because religion has had millennia to prove itself right -- millennia in which it has dominated the intellectual and scientific discourse, for all but the past few decades -- and has utterly failed. We're atheists because the religion hypothesis has been tested -- and tested and tested and tested, and tested again, and tested yet again, and then tested one more time to be sure, and given the benefit of the doubt and tested again, and then again, and again -- and has never, ever, ever panned out.



So to persuade us -- me, anyway, and I suspect many other atheists -- that a religion was correct, it would have to do more than show evidence of a few miracles in our time. It would have to explain why those miracles were happening now... and yet had somehow never happened before. It would have to explain why the world had always been best explained by physical cause and effect, but now, overnight, that had changed. Even if a 900-foot Jesus appeared in the sky tomorrow, healing amputees and unambiguously stating his message in all languages and whatnot, a religion would have to explain why God was making all this happen now... and not at any other time in human history.

Now -- and here, again, is a point I think PZ is missing -- the fact that religion has utterly failed to do this in thousands of years doesn't mean that it never, ever could. I could imagine, for instance, a malevolent trickster god, who's deliberately hidden all traces of his existence from us for hundreds of thousands of years... but who today, just to screw with us, has decided to show his existence: by healing amputees, by moving Earth into Pluto's orbit without anyone getting chilly, by writing his name in the sky in letters 100 feet tall in every language known to humanity, by making all members of the Wisconsin Evangelical Lutheran Synod, alone among all other religions, healthy and wealthy and successful beyond anyone's wildest dreams.

That's clearly not a god who's posited by any religion I know about. Not even the Wisconsin Evangelical Lutheran Synod. But he's hypothetically possible. And if this series of events happened, I would change my mind about my atheism, and I would accept this god's existence. I wouldn't necessarily worship him -- I'd probably conclude that he was a jerk, and I'd only worship him out of purely self-interested fear of getting smacked down -- but I'd conclude that he was real.



Now. Many people at this point will play the "super-advanced space alien technology" card. They'll point out, as Arthur C. Clarke did, that any sufficiently advanced technology is indistinguishable from magic. And they'll argue that "super-advanced space alien technology" would be a more plausible explanation for all these weird phenomena than supernatural gods.

And they'll have a point. You could argue, as I do, that in the face of a sudden, massive onslaught of the violations of known physical laws -- and in the face of a clear verbal message saying, "Yes, I am Loki pulling all this crap, I really am a god, so make with the burnt offerings already" -- the god hypothesis would be the most reasonable and parsimonious one. But you could also argue that the space alien hypothesis would be the most reasonable and parsimonious. After all, we know that physical life and technology exist; we don't know that supernatural beings exist. And when it comes to conflicts between natural and supernatural explanations of unexplained phenomena... well, again. in all of human history, natural explanations have won that fight time after time. Natural explanations have an entirely unbeaten, millennia- old record over supernatural ones. They should always be our go-to choice.



I don't want to get into that particular argument right here. What I do want to point out is that my conclusion -- my acceptance of the trickster god hypothesis in the face of healed amputees and changed orbits and Loki's name in the sky and so on -- would be provisional. It wouldn't be a fundamental axiom or a tenet of unshakeable faith. It would be a provisional conclusion, based on my best understanding of the best currently available evidence. If I concluded that the trickster god hypothesis was the best explanation of these weird phenomena, and then someone showed me convincing evidence that it was really super-advanced alien technology... I'd change my mind. I would renounce Loki. It'd be a provisional conclusion; a falsifiable hypothesis.

Making it completely unlike any God hypotheses I'm aware of.

Do I think my atheism could hypothetically be mistaken? Sure. I've already stated what kind of evidence would persuade me out of my atheism: I've gone out on that limb, and I stand by that limb. On that limb. Whatever. I still think atheism is falsifiable -- and I still think it ought to be falsifiable. I think it makes our atheism more philosophically sound. (Not to mention better able to stand up in a fight.)

But to persuade me that my atheism was false, I'd have to see more than just evidence for the religion hypothesis. I'd have to see a religion hypothesis that was coherent. I'd have to see a religion hypothesis that was testable, capable of making useful predictions, not shot through with internal inconsistencies and logical contradictions. I'd have to see a religion hypothesis that was worthy of the name "hypothesis." And I'd have to see a religion hypothesis that explained, not only any new evidence that seemed to support it, but the complete lack of good evidence supporting it for the thousands and thousands of years before now.

Rejecting religion isn't an unquestioned axiom. Rejecting religion is a conclusion, based on an overwhelmingly mountainous pile of unignorable evidence. And even for those atheists who are now totally convinced that this conclusion is correct, it's still a conclusion. It's not that atheism isn't falsifiable. It's that thousands of years of history have utterly failed to falsify it.

It could still happen. The trickster god could still show his 900-foot face and wow us all.

But I'm not holding my breath.