On astrology

Now, I'm not a fan of the Conservatives. As Conservatives go, I'm perhaps more amenable to our Boris. He communicates well (in his unique style) and gets people engaged and talking about politics, which is good. He does have notoriety as a bit of a buffoon, and I took advantage of that to make something of a jibe about 'the best argument against astrology ever'. Actually, I would be happy to say that Boris is very talented. The astrology chart post though, talks of him genius and high creativity, which is probably pushing it just a tad...

Anyway, the case of one chart and one notable person, subject to extreme selection, really tells us very little. It does tell us something, as if astrology asserted the patently false ("by this chart I can determine that Boris Johnson is actually a penguin") it'd obviously be evidence against, so the fact it's not completely misaligned might constitute extremely weak evidence, but nothing that would sway anyone from their current opinions on the matter.

Here are some of the things @angelneptustar has tweeted in my direction:

1. i did get it, I knew you were teasing me. I bet i could read your chart and descriBe you to a T.
2. Ed, have you studied astrology? i have, for 15 years. unless you have studied it, can you fairly commment?
3. your reply is silly. Would you commment on the validity of any subject, unless you had studied it? [my reply was to point to the Courtier's Reply]
4. I didn't accept astrology until I studied it in depth. Your remark is potty.
5. Still, Im sure you comment on politicis and you know nothing abut that subject either.

Now, on point 1. Clearly that's a bad way to test astrology. Anyone who has my Twitter account has my name, the link to this blog, and an ability to Google who I am and, as I make no particular effort to hide myself, find out an awful lot about me and the cynical old bugger I am. I pointed this out - "A fair test is not possible, but you knew that, right?" - it misses some details, but hey, it was a tweet limited to 140 characters.

On points 2 and 3, whether I can fairly comment on astrology. I think this is definitely a case for pulling out the Courtier's Reply, as mentioned. It's like criticising Ben Goldacre giving an opinion on homeopathy because he's not a homeopath. I don't need to understand the details of something to be able to fairly assess evidence for it and use that evidence to feed my 'belief engine' - the bit in my head that tells me whether I should change my mind on something. All I need to do is understand that someone has a model for how something should work, and understand if that model has been fairly tested, and how that model has been compared to observations. I think, being a well qualified scientist, that I can fairly comment.

Being a fairly long-time skeptic, and short-time magician taking advantage of people's profound ability to make errors at times, I also have a fairly good understanding of the kinds of errors that are made in assessing such evidence, outside those that usually afflict my particular area of science. So again, I think that makes me able to fairly assess a piece of evidence.

I should also say that my a priori belief in astrology is very low. It is inconsistent with my understanding of astronomy (which, angelneptustar, is considerable). Now me saying that we have no known mechanism by which astrology can work is not proof that it does not. The real watertight case is the lack of good evidence. But one should be aware that my current understanding of the world predisposes me to requiring quite extraordinary evidence for astrology in order to change my mind. This is an entirely rational stance to take.

On point 4, angelneptustar may well have not accepted astrology until studying it in depth. I have no particular reason to trust another person's ability to correctly assess the evidence, least of all if that someone chased up an a priori peculiar idea for however many years it takes to study it in depth before changing their mind. I think it doesn't take long to convince oneself that the current evidence doesn't support anything, and one should probably do something more productive or enjoyable. So sorry, angelneptustar, but while you might not accept my ability to fairly comment, I certainly don't trust yours. We clearly have different ways of thinking about this.

Point 5. Let me just add a few more tweets that have arrived while writing:

1. But you admit you know nothing abut astrology, which takes years of study.
2. I therefore dont take your remarks seriously, because you are totally ill informed.
3. But if you dont have to study astrology to know all about it, u r probably ignorant on most things.
4. And you are obviously not a political expert either.so yr blog cant be worth reading.

Now I'm not a political expert. I do know a bit about politics. I think politics is important, and I feel a responsibility to be some kind of informed voter. I am a member of a political party, write annoyed letters to my MP on various topics, and sometimes, but less often, happy letters to my MP. I try to keep up on the news, including that of political matters.

There certainly are areas I'm ill-informed on. Being ill-informed does not mean that I cannot make a good assessment of their validity. I am ill-informed on both the details of the nature of the polymerase chain reaction and also on details of voodoo rituals. I can make a good assessment despite that of which of those are founded in reality.

I take issue with the idea that I am "ignorant on most things", or "totally ill-informed". I think most people that know me know I'm not completely devoid of knowledge, or even close to devoid of knowledge (by human standards).

So let me come back to what I think is an important point about this discussion - that I must know the details of something to assess proof of its existence. It's a common criticism of skeptics that to assess astrology we must take complete and properly done charts and use those.

Now for one thing, it's still dead easy to test astrology under that premise (just like my previous post arguing that homeopathy can still be tested in a mass double-blinded trial with individualised remedies).

Secondly, by accumulating a lot of the right kind of data, statistics lets you tease out small signals and show up what would essentially be high-frequency changes in the data. I'd argue that it's actually the very best way to do it - that by numerical analysis you obtain a strong signal faster than by 'doing it by eye'.

The problem with this is that to do this, you practically by definition have already accumulated strong evidence that at least some component of astrology works, and you'd have everyone convinced. This hasn't happened.

If one actually needed a model of astrology of that complexity to determine if it worked at all, astrology would be nigh on impossible to discover. You have to build up such a wealth of data to determine the nature of the signal that it would be virtually impossible today, let alone in the time of Ptolemy or whatever (when he also didn't have the powerful statistical tools we can leverage today, or the computers to help analyse all the data flowing in, or the scientific protocols needed to do so fairly). By the very nature of a detailed and complex model, you need more data to determine if it is correct and what its parameters are. If that model worked, you'd also expect that there was some simplified version that operated with a few less parameters to get less good results, but was still unambiguously more powerful than the null hypothesis that astrology does not work in the slightest.

It's like seeing some shape in the mist and wondering if its an elephant, and having someone declaring you can't tell if its an elephant until you've measured its trunk. You'll certainly be in the position to tell whether there's a mammal of considerable size in your vicinity by the time you have got a good enough view to check the size of its nose.

As I said, this points to a big problem with the claimed history of astrology. How on earth could you determine a complex model of astrology way back in the ancient past? How on earth could we still be in the situation where evidence for astrology is anything less than absolutely unambiguous and impossible to deny, when it was possible to fit a multi-parameter model to it thousands of years ago? It isn't.

The historical nature of astrology, and its weak evidence base today both stand in absolute disagreement with the idea that astrology is supported but that you need to understand its complexity to assess it fairly.

Unfortunately angelneptustar has declared this blog not worth reading a priori, just as I've declared astrology bunkum a priori (although naturally I think I can make a stronger case for the latter than she can for the former), so this will likely be preaching to the choir.