Another update on North Head: Am I in danger of changing my mind?

A few years ago, Martin Butler provided me with a copy of his book, “Tunnel Vision”, which I reviewed here. Last year Martin updated his book (The front cover calls it “An Explosive Update”) which I’ve now read and am in the process of reviewing. I think it’s a better book now than it was a few years ago, although I’m not entirely convinced by all of Butler’s claims. That is by-the-by, however, because earlier this week I met Martin at the Torpedo Yard cafe, at the base of North Head, and I came away from that meeting a little swayed in my thinking. I’m not saying I’m now a firm believer in the existence of a cover-up to hide decaying ammunition in one of the country’s most expensive suburbs. I am, however, willing to go so far as to say there are some anomalies in the public record which suggest there is more to the North Head story that certain authorities would have us believe.

I’ve been mulling this over the last few days. My good friend and colleague, Lee Basham (of South Texas College) has long argued that I should not have closed my book with a declaration that the best conspiracy theory about the events of 9/11 is the “Al-Qaeda was responsible” theory. Rather, Lee thinks I should have just provided the methodology for the analysis of conspiracy theories and left the generation of conclusions to those who would employ my analysis. His argument was that my analysis does not need to be hitched to any particular claim to be useful. The North Head issue is a good example: when Martin and I met in person for the first time one of the first things he said to me was “So, you’ve been a skeptic about all of this for a very long time, haven’t you?”

Being known as a skeptic of something has, in the past, been something I’ve celebrated and shouted to the rooftops. However, now I think that it can be a bit of a millstone. I have no issue in changing my mind; I went from being a very devout theist to an atheist (of the “There’s no good proof for the existence of the gods, so I’m not going to believe in them until there is” variety), and I went from being a racist to a non-racist. I even started out writing a PhD on the warrant of conspiracy theories believing that we had grounds to claim said theories were prima facie unwarranted, and we’ve all seen where that got me.

So, being known as a skeptic of the view there might be something more to the North Head story can be a bit of problem. This is because sometimes people take skepticism to mean “Here is my view on x, and you are stupid to believe otherwise.” However, my skepticism of the Hidden Tunnels conspiracy theory has always been about a lack of good evidence (and there’s a phrase which needs careful unpacking). Meeting with Martin and seeing and hearing about some of the new evidence he has brought to light, has shifted my thinking.1

Here’s a quote from the end of my book.

When inferring to an explanation, ordinary reasoners might fail to consider:

1. The extent to which the available evidence that the phenomenon being explained renders the hypothesis probable (the posterior probability),
2. The degree to which the hypothesis is independently likely (the prior probability),
3. The likelihood of the hypothesis, relative to the other hypotheses being considered (the relative probability) or
4. The possibility that there are some worthwhile hypotheses which have not been considered.

Three of these issues are to do with how we consider the probability of a given hypothesis. The fourth is about the failure of ordinary reasoners to consider other worthwhile hypotheses.
(Dentith, M. R. X. ‘The Philosophy of Conspiracy Theories’, Palgrave Macmillan, 2014, p. 147)

Martin’s research, at least for me, means there is new evidence to consider. His new evidence consists of additional information about the military use of North Head and how North Head fitted into the military command structure across Aotearoa. Not just that, but he also has some interesting examples of inconsistencies in official correspondence. Some of this evidence changes the posterior probability of some version of the non-official, conspiracy theory because it not just opens up holes in official reports and statements from Ministers and senior personnel, but it also shows that people where either very lackadaisical with the truth or that they lied to either the public or members of the Government.

Now, I say “some version of the non-official, conspiracy theory” quite deliberately; if I can going to concede that it seems there is more evidence for a cover-up than I initially thought, that doesn’t require me to believe a specific conspiracy theory that says, for example, that there is decaying ammunition deep within North Head. I can believe there is evidence for a cover-up about something without having to believe something about what is being covered up. But, and this is important, I think Martin’s research increases the likelihood that some version of a conspiracy theory about North Head is true. The question is, does it change it such that it is the most probable explanatory hypothesis?

Obviously there is a tension between the posterior and relative probability of a set of hypotheses; as the posterior probability of some version of, in this case, the conspiracy theory goes up you should expect it to become relatively more probable than some other hypotheses for the same event. This is where I am at right now: the new evidence certainly increases the posterior probability of some conspiracy theory about North Head, but has the relative probability of the rival, official and non-conspiracy theory been lowered, such that some version of the conspiracy theory is now the most likely explanation? For the moment, I have no concrete answer. My gut tells me that the official theory is still the most likely explanation, but it’s not as likely (to my mind) as it was a week ago. But why trust my gut on this, rather than go back and re-examine the evidence?

Which is what I am going to do. More on this soon.


  1. I keep wanting to say things like “a little bit” and I’m honestly not sure whether that’s because I’m simply resistant to changing my mind on some of the issues.

Thesis Update: The Thick of It

You know, it doesn’t seem all that long ago that I promised that this blog would be all about upcoming chapter revisions, snippets of thesis writing and, well, a diary of how I was/am getting closer and closer to completion. I suspect I only really managed to keep that up for about two weeks, then I didn’t post anything for a while, and then it was back to sporadic postings borne of a need to make it look as if the blog was being updated.


Still, the Christchurch Earthquake material seems to have resonated with my now tripled-in-size audience and I have plans to spend a bit of time looking in/over the local version of the Chemtrails story. I also have enough new material to eventually write another post in the earthquake series. Indeed, I’m seeing a host of potential articles on matters local post the thesis.

Ah, post the thesis. What a wonderful term, and one I am beginning to believe has a truth value of “1.” Work has slowed down slightly; I had hoped to be at the end of the drafting process and in the final revision stage by now, but the latest chapter has spawned a child.

Chapter 7 (although it could end up being chapter four or five) is my analysis of the Inference to Any Old Explanation and how I think that explains our prima facie suspicion of conspiracy theories (because conspiracy theories require an Inference to the Existence of a Conspiracy and most, but not all, Inferences to the Existence of a Conspiracy are Inferences to Any Old Explanation) and, for a time, I thought that one way to explicate the Inference to Any Old Explanation was to talk about how we can design explanatory hypotheses to get the results we want. I have been persuaded that this design hypothesis of mine, which now goes by the much more inelegant but accurate name of “Selective Evidence,” really isn’t part and parcel of my analysis of Inferences to Any Old Explanation and is a separate idea which deserves its own chapter.

Which it is getting.

So, that’s the work in progress update. I would write more but, really, I should write less here and put the effort of the next paragraph or two into the open window on screen two, the one entitled “Inference2.tex.”


Inferring to the Existence of a Conspiracy

The current chapter, which really could have any number attached to it, is on the exciting and fallacious move that is inferring to any old explanation rather than to a good, let alone the best, explanation. As part of my introduction says:

Perhaps more novel-ly, I am going to argue now that a significant problem for conspiracy theories is their “Just So” nature, in that belief in a conspiracy theory requires what I will call an `Inference to Any Old Explanation1‘ or the “Just So” Fallacy. For belief in a conspiracy theory to be considered warranted an epistemic agent will need to make an Inference to the Existence of a Conspiracy. The Inference to the Existence of a Conspiracy is not something that merely affects bad conspiracy theories2 but is, rather, part of the process by which warranted and unwarranted \textit{conspiracy theories} are accepted. There will be instances of the Inference to the Existence of a Conspiracy which are warranted but, I contend, this will not be common and thus, typically, such an inference will be an example of an Inference to Any Old Explanation.

Originally this chapter was meant to be the primary and most important novelty in the thesis as a whole (such novelty is a required feature of doctoral work) but it is now just one of three novel analyses found in my thesis(or, at least, I will assert that this is the case); my analysis of Rumours (and their fit with conspiracy theories along with my disambiguation of what “officialness” means in respect to explanatory accounts, being the other two.

The Inference to the Existence of a Conspiracy analysis is something that Jon and I have been kicking around for a while; well, morese the precursor notion, the Inference to Any Old Explanation.

The Inference to Any Old Explanation is the more formal-sounding name for “Just So” stories, those wonderful tales of Rudyard Kipling. In a “Just So” story an explanation that fits the facts is presented for some phenomena, and such explanations are, in Peter Lipton’s words, lovely because the explanation promotes an understanding of why things are the way they are. The “Just So” stories of Kipling are wonderful because they present explanations of features that say “Someone (or thing) wanted it to be this way,” and this really does resemble some of the kind of reasoning conspiracy theorists engage in. “They” wanted the Twin Towers destroyed in the same way that they wanted the leopard to have spots; someone was responsible.

More importantly, for my analysis, such stories have a very designed feel to them. We know leopards have spots, so all we need is a god story to provide an explanation as to why this might be the case. In the same respect, we know the Twin Towers fell, so we need an explanation to explain why this was the case. In the leopard example the “Just So” story provides an explanation which is unlikely but lovely; the spots being painted on may make very little sense, given what we know about genetic inheritance, but it renders the feature with an aspect of understanding. In the Twin Towers example the notion that the American Government orchestrated the event is unlikely but, once again, lovely; the event must have occurred for a reason, so who better to make it occur than the world’s superpower?

Nothing in the stories, however, suggests that the proffered (better yet, candidate) explanations are likely; genetics rules against the leopard example and the long-standing analysis, understanding and knowledge of the aims of certain terrorist groups, as well as claims about the USA’s role in Middle-Eastern politics strongly suggests that it was Al-Qaeda, the group that claimed responsibility for the event, who were behind the September 11th attacks.

Now, importantly for my analysis, an Inference to the Existence of a Conspiracy is not merely an Inference to Any Old Explanation. Some Inferences to the Existence of a Conspiracy will be warranted. Explicating just how this can be the case, and why it is so hard to do, is the task that, if it weren’t the excitement of watching the finale of “LOST” tonight overriding my feelings, consumes my every waking minute (and some minutes of sleep, I must admit).


  1. Whilst this is a new term of art, I cannot claim sole credit for the name; my good friend, teaching colleague and supervisor, Dr. Jonathan McKeown-Green and I came up with the term whilst working out how to discuss conspiracy theories in the context of a critical thinking course we taught in 2004.
  2. Where `bad’ here refers to conspiracy theories which could be incoherent or false.

Chapter 5 (or 6 or 7) – The Inference to the Existence of a Conspiracy

The final chapter of my thesis, which is number 7 (in the file directory), number 6 (according to the PDF) or number 5 (as my supervisors would have it) is my third peg, so to speak, in why I think we have a prima facie case for our suspicion of conspiracy theories; they are typically examples of Inferences to Any Old Explanation (which you might know better as “Just So” stories, ala Mr. Kipling1 ).

Originally I was going to base this chapter on large chunks of Peter Lipton’s book on the Inference to the Best Explanation (which, funnily enough, is called “Inference to the Best Explanation” and was published in 2004 (the second edition) by Routledge), and not just because he specifically mentions (and then glosses over) conspiracy theories on page 60.

“Perhaps some conspiracy theories provide examples of this. By showing that many apparently unrelated events flow from a single source and many apparent coincidences are really related, such a theory may have considerable explanatory power. If only it were true, it would provide a very good explanation. That is, it is lovely. At the same time, such an explanation may be very unlikely, accepted only by those whose ability to weigh evidence has been compromised by paranoia.”

Lipton runs a contrast between the loveliness of explanations (just how powerful they are as explanatory hypotheses, essentially) and the likeliness of such explanations (i.e. just how probable is the explanatory hypothesis); he thinks2 that conspiracy theories were good explanations only in the lovely sense as they were unlikely.

Lipton doesn’t come back to conspiracy theories, which is useful for me, because, in some important respects, it rather gives away the kind of analysis I have in kind for chapter 5/6/7.

As I wrote, my original intention was to develop Lipton’s view with specific respect to conspiracy theories, but that is no longer the case. Instead, I am developing the Inference to Any Old Explanation analysis that Dr. Jonathan McKeown-Green and I worked up for our Critical Thinking course (PHIL105 to the fans) at Auckland. The Lipton material is useful in talking about when the inferential practices of epistemic agents can be said to `go right’ but my analysis is really about when such practices `go wrong.’ It is much easier to work up a bespoke philosophy/epistemology than it is to try and make the work of someone else fit your particular analysis (ask me about my MA thesis for detailed reasons as to how that doesn’t necessarily work out for the best).

Still, I should point out that whilst I was writing this post I realised that there was a particular part of Lipton’s analysis of IBE (as the cool kids these days call “Inference to the Best Explanation”) which I could use to fill this particular hashed out section of the chapter (the “%” marks are playing the role of hashes in my LaTeX documents):

%However, we should also be aware that there is a kind of tradeoff between the probability of an hypothesis and the extent to which said hypothesis suggests the explanans.

%[This is the stuff that motivates Bayesianism. We might need to say a bit about it somewhere to help set up this discussion of the Inference to Any Old Explanation.] – Will need my Goldman…

I’m no Bayes scholar; I know how the theory works and the difference between prior and posterior probabilities (which it is important never to confuse), but the specific details… Well, I’d need to spend quite some time with a primer and a notepad to get myself sufficiently up to speed on Brother Bayes and his mathematical theorems. However, Lipton has a gloss on Bayes, since Bayesianism is often trotted forth as a contender for a theory of the Inference to the Best Explanation, and so I might use the Lipton gloss (which I’ve partially written up) after all.

Which goes to show that this new “thesis-centric” blog ethos is already delivering. Huzzah.

Next time: What it is I am actually trying to say in chapter 5/6/7.


  1. And his marvellous cakes.
  2. Well, thought; Peter Lipton is dead.