Stupid Evil Bastard Les Jenkins posted a link to a quick essay by Steven D. Hales.

Everyone's quite aware of the constant refrain of fundies, woos, and other creduloids, which can be boiled down to: weird, contradictory shit we've never proven the existence of...exists. A rational skeptic replies that, since we've seen no evidence for said weird, contradictory shit...no. The creduloids then declare: "Since you can't prove it's not true, then it is!" In response, as we've often explained ourselves, we have to laboriously examine why it is, in fact, impossible to "prove a negative."

That's where Steven Hales takes us on...though, strangely, he seems to think that it's the believers claiming that you can't prove a negative. It's like the guy has heard our plaintive cry, supports what we're about...and then promptly mixes it all up and decides the creduloids are the ones he heard. What, was he in the next room with the door shut?

What we're confused about, judging by Les' (and his commenters') corroborative reactions, is this: when did this become a creduloid argument? We've had pretty extensive interactions with creduloids over the years, and we've never heard a single one use the "you can't prove a negative" argument on us to back up their own beliefs. In fact, it's been quite the opposite — we've been the ones making this assertion (with clarifications, of course) when confronted with the woo argument that the burden of proof falls on skeptics to show that their pet beliefs are not real.

Usually, the conversation goes like this:

Woo: Unicorns are real.

2%: How do you back up that stupid assertion [obligatory "asshat" type reference]?

Woo: I know they exist. It's up to you to prove that they don't exist.

2%: No, moron. It's not possible to prove that something doesn't exist. To understand why, see our post called "Only God Can Prove a Negative, and There Is No God." The burden of proof is on you to prove that your fantastic claim is true.

In our experience, it's the skeptics who need to use the "you can't prove a negative" argument, not the creduloids. However, some pretty smart people seem to be indicating that they've seen this happening in the other direction. So if the creduloids are using this argument, then someone please give us an example, any example. In all sincerity, we can't recall ever seeing an example like that, and we can't even come up with a viable way (or reason!) for the woos to use this approach. It seems like, since the assertion is "proven wrong" (not really — as this Rant discusses), some skeptics are disavowing it, and attributing it to "the enemy." If you've got a link to an actual example of a creduloid trying this one on for size, or even a sample dialogue like the one above, please let us know.

It makes little sense to us. It's to the creduloids' advantage to believe that we can prove a negative — because, if it's possible to do so, but we can't actually "satisfy" them with a proof that no, their bullshit isn't real, then they've "won" (based on the "absence of evidence" stickiness, which is one logical fallacy they're all too happy to embrace, for obvious reasons). On the other hand, it's our contention that proving a negative, given the connotation they expect, is impossible. Steve gets it the wrong way round.

He starts here:

A principle of folk logic is that one can't prove a negative.

...

But there is one big, fat problem with all this. Among professional logicians, guess how many think that you can't prove a negative? That's right: zero. Yes, Virginia, you can prove a negative, and it's easy, too.

Um...Steve? You're missing the point, here.

This isn't about logicians. Nor is it about "folk logic." Nor is it solely about abstract thinking without any other field of exploration thrown in (though certainly, as with anything humans examine, we must employ abstract thinking in order to investigate it).

The problem comes when you look all the way down at the bottom of Steven D. Hales' essay:

Steven Hales is professor of philosophy at Bloomsburg University, Pennsylvania.

Ugh. And that's why Steve is missing the point.

Listen, we have nothing against philosophers who stick to philosophy. (Just as we have nothing against economists who understand that economics is not a hard — by which we mean purely empirical and mathematical — science.) And formal logic can be a pretty fun exercise — not only did we love working that stuff through way back in school, but as we often code computer applications in both a professional and personal capacity, we apply formal logic (and its corrolated axiomatic foundations and rules of reasoning) frequently.

But when we (not the believers, Steve) explain that you "can't prove a negative," we aren't limiting ourselves to the realm of philosophy. It's not about strictly formal logic absent all empirical observation and investigation.

Steve correctly invokes the law of non-contradiction — that is, if something is P, it is not not-P, and vice versa — in his effort to show that you can prove a negative. Of course you can, Steve — in formal logic, where everything (and, more to the point, every person) is cooperative.

While seeming to imply that there are scads of reasons why you can prove a negative, Steve really only gives us three: the aforementioned law of non-contradiction (which he expands on at length in a recursive, almost "law of non-non-non-non-non-contradiction," kind of way), the power of deductive reasoning, and the power of inductive reasoning. On deductive reasoning, he says this:

Can you construct a valid deductive argument with all true premises that yields the conclusion that there are no unicorns? Sure. Here's one, using the valid inference procedure of modus tollens:

1. If unicorns had existed, then there is evidence in the fossil record.
2. There is no evidence of unicorns in the fossil record.
3. Therefore, unicorns never existed.

Someone might object that that was a bit too fast — after all, I didn't prove that the two premises were true. I just asserted that they were true. Well, that's right. However, it would be a grievous mistake to insist that someone prove all the premises of any argument they might give. Here's why. The only way to prove, say, that there is no evidence of unicorns in the fossil record, is by giving an argument to that conclusion. Of course one would then have to prove the premises of that argument by giving further arguments, and then prove the premises of those further arguments, ad infinitum.

Wow, this is maddening — no offense meant, Steve (really!), but this is what comes of philosophizing rather than diving into reality and seeing how reason and critical thought apply in real life. We often liken philosophy (for the sake of philosophy) to masturbating with ideas — even if that is offensive, we still believe it, and Steven D. Hales hasn't given us any reason to think otherwise with this essay.

See, we buy your reasoning, Steve. We agree that the three-step proof you've offered is pretty solid, since we're willing to accept the premises you assume. In fact, we can even go the next step and prove those premises with you; and the premises those premises are based on. That's why we're not the ones you should be addressing...

...because the believers are the ones who fuck up your nice, neat little package there, and not because they're claiming "you can't prove a negative." You've misaimed that attribution egregiously.

What happens, in your example, Steve, is that we offer the pretty solid logic you've written out...and the creduloids claim that the premises are incorrect. They don't do this ahead of time, of course, because none of their "hypotheses" are well-defined or thought out in the first place. But when we use the kind of logic you've demonstrated to poke holes in their hypotheses, they move the fucking goalposts.

Tell us, Steve, how would you react when, after you've presented this clever logical throughline proving that unicorns don't exist (to wit: a negative), the Unicornist purrs: "Why would there have to be fossil records of unicorns? Your first premise is flawed, Mister Smarty Science Guy."

Oh, right...explain the basics of bone structure, mineralogy, paleontology, and a few other scientific facts for them. Good thinking, Steve. Then what do you do when they explain: "No, unicorns don't have bones." Or (in a much better reflection of what these fuckholes do): "No, upon death, unicorns turn into a mystical crystalline pink powder which floats away on the wind."

Now what?

See, you seem to think that deductive reasoning holds up with people who, as you yourself state, have "a desperate desire to keep believing whatever one believes, even if all the evidence is against it." And it simply doesn't. Those of us dealing with actual believers all the fucking time, instead of simply playing games with logic and semantics, know this. They will move the goalposts every goddamn time, Steve, and your logical brilliance is not going to stop that, and it's not going to change their minds, and it's not going to do...well, pretty much anything, really.

Which, of course, is why the narrow field of "philosophy only" fails abysmally in a real world context. It's like spending your whole life as a swordsman, sharpening your sword, practicing thrusts and slashes...and never realizing that an actual, live opponent might think to block or parry your attack! Boy, would you be in for a surprise.

Steve moves on to a discussion of inductive reasoning, which is very good and all, and we agree with much of it. In fact, we use his arguments ourselves on many occasions, to deflect the usual moronic fence-sitters who think they're "enlightened" because they've come up with the ever-so-original concept that maybe we're all in the Matrix and none of what we expect is real, anyway. Steve is absolutely correct in that, in order to function in the real world, we all apply inductive reasoning not just on a daily basis, but practically a million times every minute, most of it completely unconsciously. Doing otherwise risks becoming Douglas Adams' Man in the Shack.

But his acknowledgement of the efficacy of inductive reasoning in the real world is all the more frustrating in that he can't leave his philosophical ivory tower (or even stick his head out the window) long enough to incorporate that real world knowledge into his understanding of how believer/skeptic debate works, in practice. This is very similar to why Libertarians (with a Big L) or self-professed "anarcho-capitalists" (and their ilk) fall down so fucking hard when clinging to their irrational bullshit — they rely on their own idealistic conditions as applied across the board, and fail utterly to take real world conditions into account. They miss the real world consequences of their ideas and propositions, and that's why we laugh our asses off at them.

Steve, we don't want to laugh our asses off at you, but you're forcing our hand. You've thoroughly ignored the actual world of Believer-Skeptic Conflict in your efforts to dissect the epistemological arguments. Don't like our assessment? Then stop making statements like this one:

Which premises we should take on credit and which need payment up front is a matter of long and involved debate among epistemologists.

Such blanket statements are Ivory Tower to the Max, dude. Do you really believe that the believers (and a great number of skeptics) are going to take a time out for a sideline call from the epistemological referees? Sheesh.

Take a page from Carl Sagan — or, hell, we'll do it ourselves:

"A fire-breathing dragon lives in my garage."

Suppose...I seriously make such an assertion to you....

"Show me," you say. I lead you to my garage. You look inside and see a ladder, empty paint cans, an old tricycle — but no dragon.

"Where's the dragon?" you ask.

"Oh, she's right here," I reply, waving vaguely. "I neglected to mention she's an invisible dragon."

You propose spreading flour on the floor of the garage to capture the dragon's footprints.

"Good idea," I say, "but this dragon floats in the air."

Then you'll use an infrared sensor to detect the invisible fire.

"Good idea, but the invisible fire is also heatless."

You'll spray-paint the dragon and make her visible.

"Good idea, except she's an incorporeal dragon and the paint won't stick."

And so on. I counter every physical test you propose with a special explanation of why it won't work.

We're usually quoting this kind of thing at creduloids, ending with Sagan's comment:

Now, what's the difference between an invisible, incorporeal, floating dragon who spits heatless fire and no dragon at all?

But that part is irrelevant with you, Steve. You get that. What you don't seem to get is the horrifically true existence of the entire conversation that precedes it. That is the kind of shit we're dealing with, here outside of the ivory tower.

Logically, philosophically, epistemologically, abstractly — you are correct. Absent any real life application (or implications), you've got it one hundred percent right that we can "prove" a negative. Sure thing, man.

But in reality, we are working with specific sets (a subject you should be familiar with), specific circumstances (which you clearly aren't familiar with), and specific audiences (which you've apparently completely forgotten even exist).

Our sets are literally infinite, but in a physical (or at least conceptually physical), not purely mathematical, way. The reason why we state, to the credulous believers who throw their figurative unicorns at us incessantly, that we "can't prove a negative," is because we can't empirically prove that Santa Claus, or unicorns, or gods, or ass gnomes, do not exist anywhere and everywhere — "somewhere" in the universe (or more) that we inhabit. We have no resources, time, or abilities that will enable such a "search."

Why do we state that they don't exist anywhere? Because, as you've very correctly explained, Steve, we make good use of inductive reasoning, and by that reasoning, which is supported by and supports our deductive reasoning, there's no reason to believe that these fucking imaginary figments are anywhere at all. They don't exist.

But can we "prove" it? Not in the purely mathematical, formal logic way you're getting at. Not in the least.

We suppose our real beef with Steve's essay is two-fold.

One — in our experience, as we've explained — he entirely misattributes who is saying "you can't prove a negative." That isn't the rallying cry of the creduloids, Steve, it's our response to their constantly moving goalposts which — literally and epistemologically — give them an "infinite set" within which to hide their bullshit. In doing this, they explain (poorly) why they don't need to "prove" it. And by establishing that they don't need to prove it, they assert (incorrectly) that it should therefore just be accepted as an a priori premise regardless of a lack of proof. As we've said, we understand that you can, semantically, prove a negative; but in the real world, against outright fucking liars (or the deluded and gullible), well...to quote Tommy Lee Jones, in a quiet but biting tone: "Try it."

Two — leaving aside his utter confusion as to who is saying what — Steve does what all philosophers do: he wanks a bit. Again, we don't know you, Steve, you could be an incredibly cool guy, but philosophy without practicability is fucking masturbation, and no matter how nice masturbation might be, it's ultimately fairly meaningless, and after a while it chafes. You can explain this crap 'til you're blue in the face, but until you apply a decent understanding of the real world — and people outside of your own head — it just won't amount to anything.

Take, for instance, the good old philosophical "conundrum" they call the Yorick experiment. With the necessary technological capabilities, physically separate a brain from its body, while maintaining direct remote contact (i.e., by radio signals) from each brain connection to its corresponding nervous system pathway in the body. The brain controls the body, the body relays sensory input to the brain, as if everything is normal — except they might be miles away from each other. The philosophy professor's question, meant (by far too many, though not all, philosophy professors) to "stump" the students, is this: where does the person, the identity or entity, reside — in the body or the brain? Within seconds of hearing the question, we Two Percenters had no difficulty whatsoever definitively answering: "The brain," and declaring the "puzzle" fucking stupid. Here's the easy test, you daffy philosophers: given the technology required to perform the experiment in the first place, if either the brain or the body was destroyed, which one — when hooked up to another body or brain — would still be that person? Since we know, scientifically, that all actual thought (and emotion, and memories, and therefore agency) takes place in the brain, the answer is blatantly obvious. Hooking your body up to someone else's brain would give that person's brain control of your body; hooking your brain up to someone else's body would give you control of that body. The question is fucking pointless and easily answered — not at all the "stumper" that our philosophy professors expected it to be.

Which is why philosophy is masturbation — they want to ask these seemingly big, clever, intricate questions, but aren't willing to dive into what the question is about in order to answer it. If you want to know what the sensation of penis-inside-vagina (or whatever combination floats your boat) feels like, then you're going to have to fuck...not just wack off and wonder.

We choose sex over masturbation. We choose reality over fantasy. We choose discussion over philosophy. And we choose efficacy over rhetoric. With apologies to lonely people, creduloids, philosophers, and politicians: if the latter in any of these pairs is all you've got, well, rock on with your bad self...but holy hell, what a silly way to go through life.

This rant saddens me in that it has introduced an amazing quote which I don not forsee being able to use, ever: "It's called a parry, you poncy twit". Although, I may take up sword fighting just to up the odds.

Aside from that, great post. I'm not a basher of philosophy; I do believe it is useful in the development of new thought and ideas, but seriously? That question about the body or the brain is supposed to blow my mind? Please. I hear so much philosophy in school it isn't remotely funny; International Law students making arguments about how if a would happen and then b would happen, we could end starvation, genocide, and child labor! Nevermind that a and b would never happen in the real world. Philosophy has its good qualities; generally, real world application is not one of them.

I thought about this for a while, and I suppose there is a certain angle with which the woos could use the "you can't prove a negative" argument. I think it's a matter of inflection- where we say it in exasperation after hearing about psycho-psychic-i-see-dead-people bullshit, they say it as though they've made some great argument: "That's right, you CAN'T prove a negative, HA-ha!", followed by a self congratulatory masturbation session. This makes sense to them, because the only part they see is "You can't prove...". The fuckers.

Happy New Year, Two Percent! I do hope your resolution was to continue posting regularly :).

I now have a new resolution for myself- figure out how NOT to anger yor spam filter.

I agree that a purely logical approach here makes no sense, but I don't think this argument is meant to be taken in an abstract way. I think most people take it to mean, "Since you don't have the ability to look everywhere, you can't know that the mystery in question isn't hiding somewhere."

This is the basis for belief in the Incredible Shrinking God of the Gaps. It's a standard dodge for believers, used like this: "You say there's no God, but since you can't prove a negative, you can't prove that there's no God, which means you have to admit the possibility that there is one, so your atheism makes no sense. You're being logically inconsistent. At most, you might subscribe to agnosticism." Whereas claiming a positive that nobody has seen could merely mean that nobody has seen one yet.

The paleontological argument that there are no unicorns is actually problematic, because in principle, there's no reason a unicorn couldn't exist, and we do, in fact, find fossils of previously unknown species all the time. The rhino is basically a chubby, heavily armored unicorn, after all. So who knows what somebody will dig up tomorrow? I'm not suggesting we'll find unicorn bones next week, but you get the idea.

Dawkins discusses this argument in The God Delusion, albeit in a context more or less limited to Creationism (see page 125--Dawkins is referring to gaps in the fossil record and the possibility of intelligent design lurking in those gaps, but I believe the principle extends to the gaps between atoms and galaxies just as well, and I've seen it discussed by physicists and astronomers in that sense). I see this as one of the standard lines of defense for the woos. They wouldn't be happy to discover that you can, in fact, prove a negative, because that would open them to the possibility that somebody might. Since it's physically impossible to search every nook and cranny of the universe, they are smugly secure in their belief in a God of the Gaps. I don't think they'd be nearly as secure knowing that it was possible to prove a negative, but it's just that nobody has managed to yet. As long as they know it's impossible, their belief system is pretty much impregnable.

I don't think this line of drivel is meant to sway skeptics (though it's clearly an attempt to irritate them). I think it's designed to pull in more creduloids by appearing to appeal to reason, but cleverly (or ignorantly) ignoring the explanatory power of induction, and the massive lopsidedness of the evidence (a zillion to zero). The most powerful statement a skeptic can really make is "Well, it's true that I can't prove there's no God, but I'd bet everything that there isn't, because we've been flipping that coin for thousands of years, and it's come up tails. Every. Single. Time." At some point, you have to give up looking, because there are more important things to attend to. I think this is how most former believers break free. They just get tired of never seeing the payoff and start to think maybe there's nothing behind the curtain. That's what did it for me.

Jason Spicer:

I find myself in agreement with much of what you are saying; however, I would like it if you could clarify something for me. You make the following statement:

"The paleontological argument that there are no unicorns is actually problematic, because in principle, there's no reason a unicorn couldn't exist, and we do, in fact, find fossils of previously unknown species all the time. The rhino is basically a chubby, heavily armored unicorn, after all. So who knows what somebody will dig up tomorrow? I'm not suggesting we'll find unicorn bones next week, but you get the idea."

See, I don't find this to be problematic at all. I don't believe we will find unicorn fossils for the same reason I don't believe in a diety: after examining the evidence, my judgement tells me unicorn fossils will most likely never be discovered. I guess what I am not understanding is why the fossil thing is an issue- you make essentially the same arguement regarding fossils that believers make regarding god- "who knows what somebody will dig up tomorrow" could be applied in either arguement. Simply put, I am wondering why the paleontological argument is more problematic to you than the other believer/non-believer arguements?

Also, I think your arguement that true believers wouldn't be happy to discover that you can prove a negative is flawed, in that it implies a heavy amount of doubt on their part. I would think that the believers would be overjoyed if there were a way to investigate every part of the universe for proof, as it would validate their belief, much in the same way non believers would be thrilled- I know I would be. Your comment comes across almost as though they don't fully trust in their belief, or that they think their belief is flawed, and I don't think that's true. Part of what is so interesting(and infuriating) about those who believe is how passionately they hold onto those beliefs, even in light of all scientific proof that we may throw at them.

This is more of a general question- I am wondering if atheist and agnostic have to be mutually exclusive? I have always considered myself somewhat of an agnostic atheist I suppose: I don't believe in a god, or gods, but I do concede that there is a slight possibility I am wrong- I just looked at the evidence and made a decision. I feel strongly it is the right one, but surely even atheists must doubt? I feel that without doubt you would become just as bad as all the fundamentalists out there- an extremist is still an extemist, no matter which side of the coin you choose.

Huzzah, I beat the spam filter, and spelled YOUR properly in my post! Double win!

Connie, you're correct that the two arguments are basically the same sort of inductive leap. But the argument that maybe we just haven't found a unicorn yet is more persuasive than the argument that maybe we just haven't found god (or clairvoyance, or precognition, etc) yet, because a unicorn is just a horse with a big tooth sticking out of its forehead (unless you mean the kind of unicorn that eats fairy sparkles and does magic with its horn). God and other forms of wishful thinking, on the other hand, pretty much by definition violate the laws of physics, and moreover, we've never seen examples of anything remotely like them. But it's not terribly outlandish to think we might dig up a skeleton of a one-horned eohippus some day, because there are lots of examples of animals that are pretty similar to a unicorn. Again, I don't think it will happen, primarily because there don't appear to be any members of the horse family with horns, so it would be a bit of a stretch for the DNA in question. But there's nothing in principle that would prevent a unicorn from evolving (or from being created by a suitably mad scientist). In short, the odds, though slim indeed, are better for finding a unicorn than for finding God. Admittedly, it's the difference between one in a zillion and one in a super-duper-looper-gaskillion. I wouldn't bet on either, but if I had to choose one of the two, I'd bet on the unicorn because at least it's physically possible.

As to whether the ability to prove a negative would make most believers happy, you should not make the mistake of projecting your values onto them. They don't think of proof the same way you and I do; they regard it with fear and suspicion. Think of it this way: The ability to prove them right (by looking everywhere and finding God) might be appealing, but not at the risk that they could be proved wrong (by looking everywhere and not finding God). The track record so far isn't on their side, and they know it. They have human brains just like we do, and somewhere in there, inductive reasoning is toiling away whether they like it or not. It's an evolutionary heritage that they use every day to get along in the world. Trust me, it gets applied to the search for God. This is why "creation science" was born. It's a way to stand against the tide by co-opting the language of science to sow doubt about the method and findings of science. It's a way to try to keep the gaps as large as possible so their God doesn't disappear.

Believers (the smart ones anyway) understand induction, but they consciously refuse to make the final leap from a very, very small chance to zero chance, ducking behind their faith at the last second instead. I'm sure there are plenty of believers completely blinded by their faith, but all the believers I know struggle with doubt. There is a long tradition in theology celebrating doubt as some backhanded kind of faith. Faith that overcomes doubt is stronger than faith that has never been tested. It's a weird idea, but it goes back to Doubting Thomas and further. I suspect this is the same technique as above--using the language of doubt to bolster faith. (Doubt and science are fellow travelers, of course.) And faith, after all, is of central importance to believers. If you have proof, you don't need faith, and vice versa. Another way to say that is that proof destroys faith. Since faith is a core part of their belief system, mandated, in fact, by their holy book (Torah, New Testament, or Koran, choose your poison), proof is dangerous, proof is the enemy.

Those that loudly proclaim they have no doubt are either simpletons or protesting too much. Those that say they "know" that God exists, either don't understand the verb "to know", or they are trying to convince themselves. The bottom line, and serious irony, is that faith can only endure under the protective cover of uncertainty. Proof can only do two things: Prove the faithful wrong, destroying their faith, or prove them right, destroying their faith. "You can't prove a negative" allows the faithful to continue being faithful.

Sorry about the filter, Connie — we're whitelisting now (take that, motherfucking spammers), so we're adding to the list of approved commenters as we go. You, of course, made the list now, so your further comments were not moderated.

We agree that philosophy has its uses; as we mentioned in the Rant, we have no trouble with philosophers who stick to philosophy. It's when they try and bring that fuzzy tool out of the Abstract Shed and into the Reality Yard that we get irritated. Your law student example is precisely the kind of thing we frequently talk about with regard to economists: if a and b, then maybe c...but, well, neither a nor b are particularly likely in uncontrolled circumstances (like the real world, which we don't control), and the two coinciding is so improbable as to make no odds, and a few other known and unknown factors may influence the likelihood of c resulting from them....

In short, to those who think that abstract and improbable reasoning can be readily and directly applied to real situations in the world around us: "It's called reality, you poncy twits." (That one's for you, Connie.)

— • —

Jason — we agree that we (us, and you — all the skeptics — and even the woos we're arguing with) don't take the "can't prove a negative" argument in an abstract way...but that's precisely what people like Steven Hales are doing, by ignoring the application of the argument in the real world. If you remove reality, you are talking in the abstract, period.

(Steve should also stick to his own specialty, rather than his unsuccessful attempt at paleontology, since — as you noted, Jason — the "no fossils" argument against unicorns would have worked against any number of fantastic creatures that we have since learned really existed.)

That said, after reading your example of how woos have used the "you can't prove a negative" approach, we're still confused. You said:

It's a standard dodge for believers, used like this: "You say there's no God, but since you can't prove a negative, you can't prove that there's no God, which means you have to admit the possibility that there is one, so your atheism makes no sense. You're being logically inconsistent. At most, you might subscribe to agnosticism."

So, they've used the phrase "you can't prove a negative," but they used it wrong, and it was peripheral to their argument anyway. Yeah, that sounds like a woo. However, that means that Hales' argument was not only wrong, but even if it was right, it was totally meaningless.

In your hypothetical woo's challenge, the "you can't prove a negative" part of this example is totally irrelevant. By this we mean that — with or without that particular statement — neither the intent of their argument nor our predictable response will change one iota. Look at it this way:

"You say there's no God, but since chickens have lips, you can't prove that there's no God, which means you have to admit the possibility that there is one, so your atheism makes no sense. You're being logically inconsistent. At most, you might subscribe to agnosticism."

"Chickens have lips" is about as completely relevant to this line of reasoning as "you can't prove a negative." And our response to either would eschew this superfluous statement in favor of addressing the actual point of the dissenter's argument.

Assuming for a moment that Steve's essay is accurate (we don't believe it is), we'll agree, for the sake of argument, that one can prove a negative in this context. What happens next? Do we address this point when we counter them? Should the skeptic say:

"You fool, yes you can prove a negative! Look at this essay and you'll see why! That said, though...um, yeah, it is in fact impossible to prove that there is no god. So you're right on that part, yeah, and my riposte about the negative thing turns out to be pretty silly, I guess....

"...but now let me get on to the actual answer!"

And then the skeptic can go on to explain how the odds of that god existing are as close to zero as makes no odds, we expect a certain level of certainty from reality, and so on, all the usual goodies?

See, frankly, in this hypothetical situation, the creduloid is correct — because we can't prove this particular negative (or any like it) in the realm of accessible reality. Thus, the creduloid's "argument" (that one can't prove a negative) is, in fact, quite accurate and on point...it's the extension of the argument and where the creduloid goes after that which present problems that must be addressed.

In short, perhaps the woos you've presented to us are using the "can't prove negative" argument like this...but if they are, then they are using it correctly (and Steven's argument doesn't successfully counter it). However, they are then failing to draw the correct conclusions that follow from the assertion, and which logically hold up to scrutiny.

However, in our experience, this doesn't seem to be how these arguments are presented. In order to actually "strengthen" their argument (at least from their point of view) — and this is what we personally have witnessed across the board — the creduloids would instead insist that we can prove a negative, and demand that we do, and could then claim victory when we aren't able to prove this specific negative that counters their assertion.

Our personal observations hold up even truer when you consider two typical creduloid behaviors: conflating incompatible paradigms (Second Law of Thermodynamics, anyone?), and stealing "Real Smart Guy" work to (inaccurately) use as their own.

Like Steven Hales, they conflate the abstract, purely logical form of "proving a negative" with the concrete, real world exploration of "proving a negative." The former is possible in a system of pure reason, absent the need for tangibles (though it requires more rigor than Steven applied — we'll give him the "just illustrating it" benefit of the doubt). The latter is impossible without...well, frankly, omniscience.

On the theft: these fucks love, love, love latching on to the latest "intellectual" research they can twist to suit their own purposes. The woos have been doing it with quantum physics (or rather, their own piss-poor non-understanding of it) and "vibrations" and "resonances" and so forth for years; the creationists (no matter what they want to call themselves any given week — "Intelligent Design"? Fuck you, asshats) have been doing it with every new biological study or paleontological discovery. Steven Hales is not the first pedant (said with love and fellow pedantry, Steve, we swear) to throw this stuff on the table, and we've watched woos and religiosos use the words of logicians (whom they barely understand) to hurl our eye-rolling complaints back at us: we explain why you can't "prove a negative" in the real world; they steal epistemological rationales and say we can, and that since we haven't, we are therefore simply wrong.

The further confusion we have with your proposition is based on our own observation. We don't think you'd offer this scenario without believing that you yourself have seen creduloids using "you can't prove a negative" in the manner you've suggested. But again, as we explained in our Rant, we've never personally seen it happen. We've seen exactly the opposite happen in every permutation of the situation we've observed. We can point to a lot of places on our site where we've had to assert that we're unable to prove a negative; we can't point to a single one where the creduloid has thrown it at us. So we're having a tough time understanding why this seems to be the baseline "agreed reality" that our fellow skeptics are working from.

At the very least, with such a baseline assumption, we'd expect that it would at least be common (if not frequent) for creduloids to use this argument. If so, though, then why would we — with several years of experience dealing with these asshats in just the sorts of fora where these arguments take place — be completely unaware of it? And, in fact, have only seen the exact opposite hypothesis in action?

The funny thing is, you offer a quite different example (one with which we can quite agree!) in your follow-up response:

Proof can only do two things: Prove the faithful wrong, destroying their faith, or prove them right, destroying their faith. "You can't prove a negative" allows the faithful to continue being faithful.

See, this sounds less like the creduloids are arguing that you can't prove a negative, and more like they're arguing that you can't prove anything. Now that approach we've seen — dozens and dozens of times over — "You can't prove whether god exists or not, so therefore my beliefs are unassailable." But that isn't the same as "you can't prove a negative."

The statement that "you can't prove a negative" accepts, as a given, the idea that proof is possible in the first place; otherwise, it wouldn't be necessary to specify that "a negative" is what can't be proven. Someone clinging to faith wouldn't just say that it's impossible to prove that god doesn't exist — they would also assert that it's impossible to prove that he does exist, thus alleviating them of the need to provide proof to back up his existence.

This kind of approach is pretty standard, and we can buy that, because we've seen it so often. We can even understand if that's what might have confused some of our fellow skeptics into believing they've seen creduloids offer a "you can't prove a negative" argument. However, they're really not the same thing, and we're a little concerned that conflating the two devalues the correct assertion that skeptics must maintain in their arsenal: that, in a real world setting, with real world tools at our disposal, and the whole universe to search, you really just can't prove a negative.

I read Hales' essay some time ago and came out of it thinking some similar things to you 2%ers, but when he spoke about woos using "you can't prove a negative," what sprung immediately to mind is that favorite canard of the religious and woos of every stripe: "Absence of evidence is not evidence of absence." These are very similar things to say.

And, strictly speaking, they're mostly right when they say it. It's just that, like dragons in garages, absence of evidence provides no reason for belief, and that's what matters to skeptics: methods rather than conclusions. We don't believe until there is a presence of evidence. They believe what they want until it's been disproven to their satisfaction (that is to say never).

But there are situations when they're flat wrong with the "absence of evidence" canard. Sometime skeptical blogger (and commenter here) Infophile called it the "Modus Tollens Exception," because it usually takes the form of a modus tollens argument, i.e.:

P1: If a large nuclear bomb exploded in Cleveland, then Cleveland would be reduced to a rubble pile teeming with dangerous radioactivity.
P2: Cleveland is not a rubble pile teeming with dangerous radioactivity.
C: A large nuclear bomb did not explode in Cleveland.

Some things necessarily leave behind evidence to indicate their existence, and if that evidence is absent, it really is evidence of absence. In that sense, using real-world facts and not just philosophical navel-gazing, you kind of can prove a negative. At the very least, the person arguing that a large nuke blew up in Cleveland will have to do some interesting things with the definitions of "large," "nuke," and maybe "Cleveland" to maintain that the lack of evidence doesn't conclusively show that there was no large nuclear explosion there.

I also think that Hales' point can be taken rhetorically rather than abstractly, too, in the sense that if you and the woo agree to the same set of rational criteria, "proving a negative" to him might convince him to change his mind, even if you didn't actually "prove" a negative inductively. The problem there is, however, exactly what you said: woos don't tend to follow the same rules as we do, so tying up your rhetoric with a neat bow and expecting all the woos to say "Oh, I've changed my mind! How silly I have been!" is completely unrealistic.

You can put together rhetoric that convincingly demonstrates a negative, but only if the other person is able to be convinced.

Curse you twopercenters for forcing me to do actual research, as opposed to lazy reflection. I'll see if I can dig up an example or two. I've certainly heard plenty of woos demand that skeptics prove that something doesn't exist (apparently in the believe that that is possible). But I'm pretty sure there are woos who believe in proof (or think they do), and hide their faith behind a special category of unprovability. Like I say, I'll have to go hunting for quotes.

And Akusai, you're forgetting the possiblity that a very large bulldozer scraped the radioactive rubble of Cleveland off the bedrock and dumped it in Pittsburgh, making way for a very talented landscape designer to put a perfect replica of the old Cleveland back in the crater. I'm thinking maybe that guy that designed Norway's fjiords in Hitchhiker's Guide. Or maybe that other guy that placed millions-of-years-old dinosaur fossils in the the geological strata of a 6,000-year-old Earth. Trickery abounds.

I'm not sure if Cleveland is quite crinkly enough round the edges for Slartibartfast, Jason....

And exactly, Akusai — you can't "win" (or even conclude) a game if your opponent throws down without any kind of agreement over the rules in the first place.

But you're forgetting that absence of evidence and evidence of absence are essentially the same thing...if we're willing to accept similarly shaky equations, like the idea that Steven Hales' use of the law of non-contradiction suffices to conclusively demonstrate that you can prove a negative.

Obviously, I don't buy that, but I generally go with my own home-grown aphorism on this subject: "Absence of evidence is not evidence of absence, but it sure as fuck isn't helping your case any."

Quoth Prof. Hales:

The only way to prove, say, that there is no evidence of unicorns in the fossil record, is by giving an argument to that conclusion. Of course one would then have to prove the premises of that argument by giving further arguments, and then prove the premises of those further arguments, ad infinitum.

Is it me, or this quote simply an extremely roundabout way of acknowledging that, in effect, you can't prove a negative?

Like you said, philosophers, or for that matter most professors/academics at universities, mostly interact with educated people who enjoy playing with thoughts. If you tell them most people don't use reason and logic, or compasion for that matter, the response is usually that those people are just a minority, because in their world this is true. Sometimes you can tell how long someone's been an academic by the rosy sheen in their world view.

But the brain and body question was supposed to be difficult? Are you sure that's not some type of basic philosophy meant for kids?