Here’s the story how I came to distinguish between two stances: good ol’ skepticism and something new to me that I will call incredibilism.

Before I define the term, have a sneak peek at an example, courtesy of Geoff Chambers:

Let’s take an example from the familiar world of vital statistics – women’s breast sizes […] We plot them along the x axis, from A to triple F or whatever. We know that B is the mean, and that a size smaller than A is impossible, so we naturally expect a skewed distribution with a long tail trailing off into the realms of fantasy. […] What do these graphs mean? If you’re Landowsky [sic], they mean that the less you know about women, the more likely you are to think you’re going to meet a woman with really enormous ones. In your dreams. And the more you think that, the more necessary it is to be prepared to meet such a woman, because you never know, and the less you know, the more prepared you need to be. [Our emphasis.]

What matters here is not the validity of that example, but its expression of incredulity. By replacing “Landowsky” by S (for Stephan, actually Stephan Lewandowsky) and “Geoff Chambers” by G to represent the two positions expressed above, we get the skeleton of an incredulous stance against a proposition P:

[The incredulous stance] Against P (claimed by S), G claims that P is incredible: G can’t believe that P. Therefore G concludes that P can only be the result of something silly: a sleight of hand, stupidity, or else.

If we read the whole exchange, we see that G also disbelieves that anyone could believe that P. We can surmise that it’s quite common. Once we find P incredible, we could easily be led to disbelieve that people could believe that P. But this particular disbelief is not essential to the what is defined here as an incredulous stance. Rather, let’s focus on the point that G expresses the belief that P, as propounded by S, is simply incredible.

The incredulous stance relies on one’s own sense of incredulity. We can see how it limits the power of such a stance by returning to the bra example. In the sentence we emphasized in Geoff’s quote, it is not clear on what authority Geoff can presume men’s dreams. They’re certainly not mine. Let’s hope that contradicting Geoff’s sexual stereotype will encourage more study about uncertainty.


Arguing from incredulity is only a kind of argument, while incredibilism is not only an argument from incredulity: it’s an overall stance by which a proposition is being portrayed as incredible. Skepticism, on the other hand, is an overall principle which guides epistemic practices. Here’s how I would abstractly describe what I believe is the essential part of skepticism:

[The skeptical stance] S claims that P. G asks on what basis is P asserted. S offers an argument: a conclusion C following some assumptions A. G can question the choices of A; G can ask if the conclusion follows from A; G can ask how to interpret C; and so on.

This description does not replace an introduction to the overall topic of skepticism, but will have to do for the moment. For a state-of-the-art paper on the subject, I suggest **Closure Reconsidered** by Yuval Avnur.

According to our definition, endorsing a skeptical stance entails refraining from having a dog in the fight. That’s what requires to be thoroughly and only questioning every step of the argumentative process. A person who endorses the skeptical stance forces his interlocutor to come up with the best argument the exchange can produce. This is not what happens when someone endorses an incredulous stance. As underlined by the quote above, and more directly by the sentence we emphasized (in your dreams), all that obtains is the a state where an incredulous person convinced himself that he simply couldn’t believe some claim.

From an incredibilist perspective, just about anything could raise suspicion. When we reach this sorry state, the incredulous stance seems almost hermetic: if I can justify my disbelief on the grounds that a claim can’t be true, or alternatively, that it’s too cute to be true, I then might have a tough time changing my mind about any claim at all. Once I let my incredulity guide my beliefs I am immune to argument and to evidence.


So which stance would you prefer to face, the skeptical one or the incredulous one?

It is by asking myself that rhetorical question that I found the word incredibilism. I hesitated before telling this story, which I’m telling more or less the same way I told Michael the last time we met in Montreal. First, it rests on a gruesome backstory: see below. Second, it is complicated by this retrospective realization: Michael’s post about the Statues that Walked, where Michael clearly argues from incredulity. For instance:

[W]hat especially turned me back to Diamond’s side of the story was the “Statues that Walked” hypothesis. Lipo and Hunt propose that rather than rolling the massive stone obelisks down the hill, they were tilted upright at the mine, and shifted down the hill vertically! Now why the hell would anyone do that?

Indeed, that story is quite incredible. But that does not mean that it ain’t plausible: in fact, it’s way too plausible. It is so perfect that I attempted this pastiche at Keith’s.

Arguing from incredulity generally lacks credibility because it has the curious tendency to be backed up by other arguments from incredulity. When the incredulity is justified, an argument stays on the table as long as it’s not replaced by a better one. Therefore, an incredulous chap always needs another counter-argument to beat the one he finds incredible.


This is where my story ends. I’m not sure how to conclude. Sometimes, trusting one’s incredulity seems useful. Sometimes, as we saw, it’s suboptimal. In any case, the skeptical stance, as underlined above, seems like a more constructive strategy. In doubt, asking questions is rarely a bad move. Unless, of course, it leads to analysis paralysis.

The incredulous stance seems pervasive in climate blogland. The skeptical stance, as I just described, might very well be quite rare. In a way, we already knew that. I can’t believe I am writing this story. This incredulity could be hidden behind the fact that Michael Made Me Do It. He’s the one who suggested that I write this story and the backstory that follows.


Once upon a time, Stephan Lewandowsky wrote a series of posts, the last one republished here, arguing for the inescapable implication of uncertainty. This implication, that lies beyond our story, was criticized by Ben Pile in a such a fashion that James Annan, the James Guthrie Award winner for 2010, called “a really strange attempt“. So there are four posts to read before getting to our backstory. Five if we like to be thorough, and we all know that auditors like to be thorough . The Woody Award post is only mentioned to plug NG’s: please do go read NG’s if you don’t already.

Our backstory begins in the comment sections of Ben’s and James’. Among the numerous comments, the most interesting exchange, to me, was the one between Tom Fid and Ben’s guild. The less interesting one was between me and Pile, which we can’t read anymore since Ben wisely decided to delete it, thereby breaking a promise. By chance, our story is not about these 15 deleted comments or so, but please do go read the Ben’s beautified comment thread: it’s quite neat and tidy.

Our story is a small part of my exchange between Geoff Chambers and me at James’, where it can be seen that the backstory has no direct relevance to the story I told. This exchange partakes of a discussion where Geoff finds many things incredible, among them the way he gets treated at James’. Our backstory is even more insightful in the light of a related backstory at the Oil Drum, courtesy of WebHubTelescope.

In many ways, our backstory is even more incredible than our story.



  1. Well, to be fair Michael did state what his incredulity was based on, i.e. his engineering background, leading to the conclusion that statues of that size transported vertically using available technology will fall down and break a whole bunch. So his incredulity was *engineering* incredulity rather than the form of argument based on evidenceless *personal* incredulity (Dawkins' phrase IIRC) that I think you're really going after here.

    While we're on the subject, it occurs to me (didn't re-read the relevant threads, so perhaps this isn't original) that a major flaw in L&H's reasoning was to assert that contemporary Rapanuian legends of "statues that walk" transmitted over many, many generations must be literally true. More parsimonious, I think, would be to point to the human capacity for metaphor and out-and-out making stuff up. It's how we roll, after all.

  2. Steve Bloom,

    Thank you for your comment.

    I'm trying to generalize to every form of incredulous stances, including Michael's. Since my point is general, I have not tried to draw the fine line between justified or unjustified incredulity. So I won't rehearse the L&H argument with you.

    There is no problem with incredulity per se. I can't say the same with the overall stance. To me, the skeptical stance is a bit better. Both can be abused pretty easily.

    In fact, the main difference between the two stances are first and foremost rhetorical.

    The skeptical chap will ask a question, e.g.:

    - Are you sure?
    - Are you kidding?
    - Do you have evidence?
    - Does the conclusion follow from the premises?

    The incredulous chap will turn these into interjections:

    - You can be sure!
    - You are kidding me!
    - What kind of evidence is that!
    - That conclusion can never follow from these premises!

    Or something like that.

    There is still **room** to bring forth arguments against someone who adopts an incredulous stance. One can still fight the preliminary judgement, according to which one's position ranges from biased to irrational. But we have to admit that this room might not always seem inviting.

  3. While surfing my tumblog, I found this discursive pattern:

    > You have no idea what you're talking about.

    I believe this goes a bit further than incredibilism.

    We might be able to build an whole range of discursive patterns like that.

  4. Modal logic (there are many) can be used to formalize states of belief or knowledge. Such modal logics arre usually S$ or a close variant. What has been called belief logic was found be inconsistent when the ground logic is the usual (full) first order logic. However, the difficulties are removed by restricting to just that fragment of first order logic called relevant (or relevance) logic.

    Stating "that's incredibile" is certainly a statement of belief. The brief description in the prior paragraph points out the necessity of a somewhat narrow stance in making logical arguments for or against it, in order to remain relevant.

  5. Good of you to link to our exchange, since it enables readers to ascertain for themselves that everything you say about me and the argument from incredibilism is false.
    My apologies for getting Lewandowsky’s name wrong.

  6. David B. Benson,

    Modal logics are certainly the most natural kinds of logics to talk about knowledge and belief. Though it seems possible to represent reasoning about time and knowledge in first-order logic. For instance, Belardinelli & Lomuscio proposed a sound and complete axiomatization for message-passing systems:

    As you also note, relevance logics are another way to refine quantification. For instance, Mares & Goldblatt interpret universal quantification (V) this way:

    > ‘VxA’ is true at a world a if and only if there is some proposition X such that (i) X entails that A holds of every individual and (ii) X obtains at a.

    To formalize what I'm saying would certainly be a great idea. But a formalism only helps when we already have a fairly good idea of what we're exploring, which was the point of my note on incredibilism. So I would like you to clarify what you have in mind with the "necessity of a somewhat narrow stance in making logical arguments for or against it, in order to remain relevant."

    The incredulous stance is certainly related to something like a disbelief operator: if Bp means "believing that p", the disbelief could maximally be read as NEC(~Bp), i.e. "It is impossible to believe that p". But that's not how we should portray this.

    A skeptic questions the justification of a claim, whereas an incredulous disbelieves this same justification. There is a difference, because the incredulous believes something whence the skeptic suspends his belief. Nevertheless, in principle, both are open to the possibility that the justification of a belief could itself become justified.

    So perhaps we could explore justification logic, for which the Stanford entry provides a nice introduction:

    Thank you for your comment,


  7. And to enable readers even more, here's another sneak peek:

    [willard] consider the fact that what you're saying so far sounds a lot like an appeal to incredulity”.

    [Geoff] YES! That’s EXACTLY what I’m saying! (though some call it scepticism)

  8. Regarding the Easter Island kerfuffle, I have no more expertise as a mechanical or civil engineer than the next person, except for an elegant required course as an undergrad in the mathematics of structures like steel bridges. I have no idea why they required it of EEs, but it was one of my favorites. But is has no bearing (no pun intended) on the problem of moving obelisks with ropes and logs.

    That said, Steve Bloom's point is roughly on target. Allow me to elaborate.

    My incredulity stems from this: the whole Easter Island mystery stems from the question of how a primitive culture with a small population mustered enough surplus energy (in the literal sense of calories expended) to erect something like as many massive statues as you will find in Paris. And Lipo and Hunt's "answer" is to make the problem harder by increasing the amount of extra work required. My incredulity stems from the fact that their "answer" is incoherent to the main quantitative issue.

    That everything else in their "narrative" can be seen as neatly designed to do two things 1) protect the cultural self-image of the Rapa Nui people themselves and 2) deny the importance of the events as a parable of modern excess strongly suggests that their suggestion is all about confirmation bias and not at all about fair-minded weighing of the evidence. In short, another instance of denialism.

    But the key point is that to the question "how the hell could those poor sods afford a new Mercedes?" Lipo and Hunt propose the answer that "there was no Mercedes, there were twelve Lexuses and an eighty foot yacht". This kicks off incredulity, which in turn kicks off examination of the rest of their argument.

    I think you will find that the roots of incedibilism are the same. If you make a claim that calls core beliefs into question (in my case conservation of energy, in G's case, perhaps a core belief that one country has no rights to object to the internal behavior of another country) the natural response is to find holes in the argument and construct a counter-narrative.

    The distinction between our incredibilisms, I contend, is that G's core belief is contingent and may change given circumstances, while mine is a feature of the physical structure of the universe and beyond human intervention.

    That is, if it were true that the universe were constructed that there is no possible way that the internal behavior of one country could affect other countries, then the whole global warming narrative would be deeply implausible, and the correct response would be to look for its flaws.

    But it is true that people cannot expend more energy than they have, and in a culture without domesticated animals or machines, that is no more energy than what they eat minus what they need to maintain their metabolism. Clearly they used a huge proportion of their surplus on statue-building. How and why are the key mysteries of Easter Island. It is nothing resembling a solution to the mystery to make the work more difficult. I find it incredible not on cultural but on physical grounds.

    So my claim is that while this sort of incredibilism based on core scientific principles is extremely valuable, basing it on social norms is a shabby and indefensible thing. One commonly finds the nonscientific ones attached to the most indefensible of institutions and habits of thought. For instance, that the South cannot abandon slavery, because slavery is part of the culture of the South. Or that we can never make peace with Muslim nations, because Muslim nations do not like us. Or that we can never put a cap on carbon emissions, because people do not like taxes or rationing. This sort of incredibilism is what will kill us, and it commonly amounts to little more than begging the question.

    But when I say something like "woot - you just violated the second law of thermodynamics" only two possibilities present themselves. Either my analysis is wrong such that your position can be reconciled to the second law, or your claim is incorrect. The second law itself is not disputable in any reasonably mundane context. Attachment to the second law is far more justifiable than attachment to any political or social generalization, be it Iron or otherwise.

    In short, I claim an unique epistemologically privileged status for scientific knowledge, and that without that status for science, no understanding of the world is adequate.

  9. willard --- Thank you for the links; I've started on the justification logic intorduction.

    My comment was (and still is) intended only to mention that (for me) the argument (even if informal) for one or another stance of credible/incredible needs close attention to relevancy (defined formally if possible). There is no hint or suggestion that the essay on this thread does not meet this standard of relevancy.

    Without delling on just why, I vastly prefer a formalistic approach (even if 'wrong' and so subjecft the modification). In priciple that ought even to apply to establishing a formal reasoning sysytem, although that rarely happens.

    Once again thank you the links in your thoughtful reply. I see that I shll be rather occupied with reading those just now.

  10. So Willard, in this circumstance would it have been preferable for Michael to have taken the skeptical approach you outlined above rather than the one he did? If so, would that not have involved a degree of dishonesty, or less pejoratively of form disconnected from substance? To what end? Just to be polite, or to seek some advantage? I'm reminded of Woody Allen's comment about sincerity...

    Just to clarify a point re H+L, they seem to have backed into the upright statue moving idea as a way to counter the proposal that the palms got used up as rollers or skids. Except, except... the palms are indeed all gone (and went rather quickly), and if they went from one or more of the apparent alternatives, burning for crops or direct consumption (palm hearts being edible), or indeed some combination of all of these, it seems to beg the question of what point H+L are really trying to make.

  11. So Willard, in this circumstance would it have been preferable for Michael to have taken the skeptical approach you outlined above rather than the one he did? If so, would that not have involved a degree of dishonesty, or less pejoratively of form disconnected from substance? To what end? Just to be polite, or to seek some advantage? I’m reminded of Woody Allen’s comment about sincerity…

    Just to clarify a point re H+L, they seem to have backed into the upright statue moving idea as a way to counter the proposal that the palms got used up as rollers or skids. Except, except… the palms are indeed all gone (and went rather quickly), and if they went from one or more of the apparent alternatives, burning for crops or direct consumption (palm hearts being edible), or indeed some combination of all of these, it seems to beg the question of what point H+L are really trying to make.

  12. Umm

    "an unique epistemologically privileged status for scientific knowledge"

    Are we talking to ourselves yet? I am totally on board that knowledge is deserving of respect, and accumulated knowledge worthy of study, but seriously ... epistemologically?

    We do have problems with meritocracies because people like to think they are as good as the next guy, but blinding them with polysyllabism doesn't seem to me to solve anything.
    Moving on, I blame the explosion of acquisition, particularly instant media devices, that allow kids to ignore almost all of school. In addition, we encourage contempt for teachers by, among other things, paying them badly.
    Sorry, this is a shallowish comment but I hope this shows I both agree and disagree but wish we'd stop being so fond of using all that language we worked so hard to acquire. It hasn't a snowball's chance in hell of convincing anyone outside the choir.

  13. Well, my excuse is that Willard attracts an unusual audience to begin with. He's studying rhetoric but I'm interested in epistemology.

    So my point in plain language is that I admit my argument resemble's G's rhetorically, per Willard's observation. Still I maintain that my confidence is not based on my personal arrogance, but on the claim that my pre-existing set of accepted ideas has a stronger foundation.

  14. Funny, reminds when when I took up Timothy Chase on objectivism, and was humbled, though I'm still agin' it. Teleologically speaking ... well, had to look it up, and that's just sloppy. But can't resist since I was exposed to both words at roughly the same time.

    I'm all for your brand of arrogance - somebody has to have authority, and I'd rather it's somebody who actually learns and works at understanding.

  15. Steve Bloom,

    I'll try to comment in more detail later this week.

    First, I want to point out that you're basically asking me Michael's question:

    Now Hunt and Lipo show up. (Diamond, whom I invited, so far has not.) So, should I not have given my ideas, or should I back off them? The sequence matters here. You are so sure I did something wrong and offer me a learning experience. Fine, teach me.

    But what? Where did I go wrong?

    I believe that my post shows both that Michael's reaction makes sense, and that Michael's reaction might not have been optimal.

    I won't pursue this point for now, and will simply share with you this thought PDA recalled on his tumblog a while ago:

    > If you want to realize the truth, don’t be for or against. The struggle between good and evil
    is the primal disease of the mind.

    Please bear in mind that my take on all this is primarily descriptive. In other words, I don't give a damn how people interact towards one another. I do take for granted that the Internet is a dog eat dog world and am not here to tone troll anyone.

  16. Michael,

    You seem to presume that unless a scientist is willing calling BS when he sees it, he has no INTEGRITY(tm).

    First, in a public forum, it could be tough to distinguish collegiality from contempt.

    Second, appealing to incredulity is an appeal to authority, on a subject you have none.

    Third, the call preceded paying due diligence to the authors' argument, and was based on their own storification.

    Fourth, to "call BS" is unnecessary for BS to be shown.

    Fifth, criticism should be reserved to stuff that matters, ergo stuff that is not utter BS.

    Sixth, sincerity is not compromised by saying only what needs to be said for the conversation to get going.

    Seventh, whereas expressing incredulity toward such and such argument is justified and even required in face of the complex world we try to understand, rejecting someone's work by piling on incredulity arguments is usually quite weak.

    I hope these are enough reasons to convey that I remain unconvinced by your justification.

    Not that I don't undersand it, mind you.

  17. OK, apologies all around, for not RTF text. Turns out my father shares MT's favorite "epistemology" so we had quite a discussion about it this morning.* While continuing to push against obscure arguments and long words in the dangerous present, when getting people to share understanding is key, I now have a better understanding of what started this discussion.

    As to the original article, I quite liked incredibilism as a description of one aspect of the public fog, but the more I read the explanation the more fogged I became. The male-centric example didn't help either.

    Some of the links were interesting though.

    *Turns out I could describe some of my preoccupations as an interest in the science (sic) of what we *don't* know, or perhaps can't know. One problem prevalent in these arguments is that people dismiss expertise and distrust that which is over their heads (except when they need it, as in medicine or plumbing).

  18. Willard asked me if the example were tasteless, and I said "slightly, but we'll get away with it". I hope it's not too distracting.

    It doesn't do G any credit that this is the example he constructed. Perhaps it is a cheap trick to discredit incredibilism to use an obviously ludicrous example. I guess this means Willard is not above rhetorical tricks himself.

    I think "incredibilism" as "stance" is quite insightful. It is a particular form of denial, and once you start looking for it, it is not hard to find examples.

  19. An earlier comment bought up conservation of energy as epistemically superior. I will now briefly demonstrate that the law of energy conservation is a justified true belief.

    I simply accepted the professor's word for it. Only rather recently have I discovered what the textbook (and the professor) ought to have communicated: Emmy Neother's (first) theorem. Not even the exact statement of it, as being too difficult for freshmen, so certainly not the proof either. Rather, the direct consequence that for every (suitable crafted) physical experiment, a physical conservation law. Here it is for energy conseravtion:

    Set up a billard shot on the pool table, conduct to observe which pocket the billard ball went into. Now set it up again, take the shot and observe the same result.

    Therefore, by Emmy Noether's (first) theorem, energy is conserved; 'energy conservation' is now a justified true belief.

    However, while this should convince even the most skeptical, I hasten to point out that, even locally in time and space, it isn't actually precisely so: Einstein's special relativity is enough to establish E=mc^2 and so one now has to write 'mass-energy conservation'. Matters become even more complex at the scale of the observable universe.

    So 'energy conservation' is a justified (almost) true belief.

  20. Somewhat related:

    > Generally, if one is trying to convince others of the validity of one’s ideas, it pays to be modest and willing to learn about points where one may be less expert than the person one is trying to convince.

  21. Michael,

    Knowledge could be defined as justified true belief:

    What I believe David is trying to show that energy conservation is knowledge.

    The tricky part, in this adequation, is the truth part: truth is easier to preserve with claims that look less empirical and more formal.

    That said, being able to tap in a knowledge base like the conservation of energy is a great asset. This is a privilege I would like to have. It does not guarantee that people like to conserve energy (this comment provides an existential proof), but it's an upper bound for what people can do in general, and in statues in particular.

    Being able to have a law of energy of conversation would be nice.

  22. Willard, all your enumerated points are arguably justifiable except point five. Easter Island matters.

    This is the lesson of post normal science. Things that matter engender controversies that would never be tolerated on less significant issues. If Easter Island were not of particular interest in its reflection on other controversies, Lipo and Hunt would either never have been published or never have been noticed. I pointed out that L + H had all the stigmata of academic denialism.

    But you are right, I suppose, that the fact of being angry and contemptuous did not necessarily tactically justify my expression of contempt. Yet, the Easter Island thread was the most successful thread on the site, in terms of the dialog it started. So our culture does not reward dignified understatement. Being on the web amounts to contention for attention.

    That confessed, make no mistake. My anger toward what I still take to be L + H's shoddy and pre-motivated scholarship is unabated and unfeigned.

  23. Michael,

    My point is that if what Lipo & Hunt say about Easter Island matters, then what they say can't be complete BS.

    What is not BS must be distilled from what you believe is complete BS, at the very least to underline the specific points of controversy.

    This has the advantage of focusing on the real, specific points of controversy, and not Lipo & Hunt's academic opportunism. This emphasis on the controversy is important, as you say, if only it amounts to more eyeballs.

    This emphasis elevates the importance of the debate: we need to preserve what's good in our knowledge about Easter Island, we need to understand the importance of Easter Island, etc. Promoting a considerate debate centered on a controversy could have a positive impact, and still attract eyeballs.

    I'm not sure we can make people read any news without narrating or editorializing about a controversy. But I'm sure we need more eyeballs.

    And not only the usual eyeballs.

  24. I basically agree with avoiding polysyllabism for polysyllabism's sake, but there's no entry for "epistemologically" in my thesaurus. I'm not even sure how one would reword the phrase to avoid using the ten-dollar word.

    A wiser man than me suggested everything ought to be made as simple as possible, but not simpler.

  25. "My point is that if what Lipo & Hunt say about Easter Island matters, then what they say can’t be complete BS."

    Why not? What is said at Watts' site is often complete BS, but people who don't know better add it to their pile of suspicion and hostility towards genuine expertise on these matters. Charlatanry like this for instance does not matter to science, but it is one more brick in the wall of delusion and so it matters to discourse.

  26. > Why not?

    Because it's not worth your time.

    At the very least, one should study why utter BS is so attractive.

    But then, if it's attractive, it's not utter BS, isn't it?

    In other words:

  27. Michael Tobis --- When I took Physics 1 I accepted that energy is conserved based solely upon the professor's authority. Appealing to Emmy Noether's (first) theorem enables one to empirically demonstrate the validity of the law of (local) energy conservation.

    My apologies for not making the point clear.

  28. I note this reminder of how sincere efforts at communication can be wasted or even counter-productive if the target audience is insincere (as Jeff Id also, which Gavin and Eric clearly knew at the time of that exchange but Michael apparently did not).

    It's interesting how Obama has done himself considerable damage by compromising with his opposition's positions rather than with the opposition itself, amounting to some unpleasant slides of the Overton window. To all appearances he will spend the next four years doing the same.

  29. True. It is puzzling that Obama, who has daughters, has bought the product from the denial PR machine. He is neither illiterate nor has he been deprived of access to people who know what they are talking about. I used to think it must be blackmail. Now I am baffled as climate evidence in real time piles up, with cost implications that should be startling to someone who is even moderately observant.

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