Sunday, May 30, 2010
Acupuncture Revisited: Idiot Edition
http://news.cnet.com/8301-27083_3-20006371-247.html
I think what bugs me the most is that the idiot who wrote the article, Elizabeth Armstrong Moore, calls herself "a skeptic". It's like homeopaths calling themselves "practitioners of evidenced-based medicine".
The argument in the article is as follows: some doctors poked mice with needles, and they noticed an upswing in adenosine, and anti-inflammatory, soothing chemical. Therefore acupuncture is not a hoax, it works, and we should all carry around personal acupuncture kits.
You really can't make this shit up. Recall what we learned last time, when we looked at a recent meta-analysis of acupuncture treatments in BMJ:
"A small analgesic effect of acupuncture was found, which seems to lack clinical relevance and cannot be clearly distinguished from bias. Whether needling at acupuncture points, or at any site, reduces pain independently of the psychological impact of the treatment ritual is unclear."
Moore says that there is a "seeming lack of evidence" that acupuncture works. But the case is stronger than that. We have a seeming presence of evidence that acupuncture does not work. It "seems to lack clinical relevance". "Clinical relevance" means "works".
The problem for acupuncture is NOT that there's no plausible physical mechanism by which it might work. Our real skeptic, Orac, said this: "there are needles breaking the skin in acupuncture. It was, at least to me, not entirely implausible that that might have some sort of physiologic effect." The problem is that EVEN IF there's a plausible physical mechanism by which it works and EVEN IF it does in fact cause an increase in adenosine, we still KNOW that it isn't clinically significant. You can't improve people's health by using it, beyond what you could do by giving people placebos. It may "do something". But doing something is not the same as working. No one doubts that sticking needles into someone does something. But why do it if it doesn't relieve their pain?
Furthermore, the journalist (I don't use scare-quotes, because this is about the level of nonsense I expect from journalists) goes on to say that because mice have elevated adenosine when pricked with needles, we should download "an app, called Qpalm Acupuncture, that maps out acupoints and formulae for treating 59 diseases. and another, iLocate-Acupuncture, for finding acupuncturists near you." That's right, needles can fool the body into thinking it's been damaged. Therefore, it's important to stick needles into those exact places that ancient Chinese pseudoscientists thought were points through which the qi flowed, and acupuncture can *cure diseases*. Aaaaaaaaaaaagh! The stupid.
Skeptic my ass.
Wednesday, December 23, 2009
Pesky Truth-Tables
http://www.soulphysics.org/2009/12/where-material-conditional-gets-its.html
I tried to comment, but it didn't work for some reason. Here's how I explain the troublesome cases (where P is false, but (P -> Q) is true).
Suppose Q is true, and P false. All we really need is that Q is true:
1. Q / Q
Monotonicity gets us:
2. P, Q / Q
And then by conditional proof we derive:
3. Q / P -> Q
One final application of monotonicity:
4. ~P, Q / P -> Q
So to reject (P -> Q) when P is false an Q true, the student must reject either conditional proof or monotonicity.
Now suppose P is false and Q is also false. All we really need is that P is false:
1. ~P / ~P
Again, by monotonicity, and conditional proof:
2. ~Q, ~P / ~P
3. ~P / ~Q -> ~P
Here there are several ways to proceed (contraposition being the most obvious). Let's try Modus Tollens:
4. P / P (assumption for CP)
5. P / ~~P (double negation, 4)
6. P, ~P / ~~Q (modus tollens, 3, 5)
7. P, ~P / Q (double negation, 6)
8. ~P / P -> Q (conditional proof, 7)
9. ~P, ~Q / P -> Q (monotonicity, 8)
So to reject (P -> Q) when P and Q are both false, the student must reject conditional proof, double negation, monotonicity, or modus tollens (alternatively, the student must reject conditional proof, monotonicity, or contraposition).
Of course, as pointed out last time, modus tollens, contraposition, disjunctive syllogism, and reductio are all inter-derivable. So my explanation is really of the form: everything follows from a false premise, so get used to it.
Wednesday, November 11, 2009
Independence of Reductio
Such a system seems simple and intuitive, but I don't see how to do it. At a minimum, we should be able to prove p & ~p -> q from the introduction and elimination rules alone, but I haven't been able to prove it. You can get it assuming any of the principles we've ruled out, e.g. modus tollens, contraposition, or disjunctive syllogism. For example (using / as a turnstile):
1. {p & ~p} / p & ~p (Assumption)
2. {p & ~p} / p (&-elim, 1)
3. {p & ~p} / ~p (&-elim, 1)
4. {~q} / ~q (Assumption)
5. {p & ~p, ~q} / p & ~q (&-intro, 2, 4)
6. {p & ~p, ~q} / p (&-elim, 5)
7. {p & ~p} / ~q -> p (->-intro, 6)
8. {p & ~p} / ~~q (MODUS TOLLENS, 3, 7)
9. {p & ~p} / q (~-elim, 8)
10. / (p & ~p) -> q (->-intro, 9)
The proof assuming contraposition is similar, but instead we show ~p -> ~q (using ~p where we have p in lines 5-7), contrapose, and use p and ->-elim to conclude q (rather than ~p and modus tollens). For disjunctive syllogism, the proof is even simpler:
1. {p & ~p} / p & ~p (Assumption)
2. {p & ~p} / p (&-elim, 1)
3. {p & ~p} / p v q (v-intro, 2)
4. {p & ~p} / ~p (&-elim, 1)
5. {p & ~p} / q (DISJUNCTIVE SYLLOGISM, 3, 4)
6. / (p & ~p) -> q (->-intro, 5)
What's more, we can prove any of these rules (modus tollens, contraposition, disjunctive syllogism) by assuming reductio (it's an easy exercise). So it follows that if we can prove any of these four rules from Assumption and the intro and elimination rules, our system is complete (well, it doesn't follow per se, but I could show you, if asked).
So, here's what I want to know from my readers, few though they may be. Can you prove reductio, modus tollens, contraposition, or disjunctive syllogism from just the intro and elimination rules? And if not, why not? Why does a complete propositional calculus need something other than the intro and elimination rules? I feel like this is something I should've learned in logic, but never did.
(Aside: yes, I know this post is going to make me look foolish when someone presents the answer, whatever it is. So be it.)
Wednesday, July 1, 2009
Acupuncture: Evidence
So the other day I was at a friend’s house and the topic of acupuncture came up. Now, I’m one of those hard-line skeptics about “alternative” medicine, and I happened to have read several credible sources stating that acupuncture doesn’t work (is no better than a placebo treatment). But not everyone wanted to take me on my word, so I promised to produce the evidence. Here we go.
First, a caveat for those who want to do their own internet research: there are a large number of biased websites out there, on both sides. If you go to the websites of people who practice acupuncture, you’ll find links to many articles which indicate that acupuncture is beneficial. Don’t trust them! For example, on this website:
You’ll find the oft-cited claim that acupuncture helps with in-vitro fertilization. Yet, the study linked is a poor one, and the most systematic review to date on the subject, here:
Concludes: “Acupuncture performed on the day of ET [Embryo Transfer] shows a beneficial effect on the live birth rate; however, with the present evidence this could be attributed to placebo effect and the small number of women included in the trials. Acupuncture should not be offered during the luteal phase in routine clinical practice until further evidence is available from sufficiently powered RCTs [Randomized Clinical Trials].”
Translation: poorly conducted studies are inconclusive. Internet researchers should also be warned about overzealous skeptic sites, which will publicize the negative results that suit them, but not take the time to consider studies which seem at-odds with their views.
The best place to get your scientific evidence concerning medicine is, of course, from recent, systematic meta-analyses of randomized clinical trials published in leading medical journals. Here is one such meta-analysis, published in BMJ. The article is: “Acupuncture treatment for pain: systematic review of randomized clinical trials with acupuncture, placebo acupuncture, and no acupuncture groups” by Matias Vested Madsen, Peter C Gøtzsche and Asbjørn Hróbjartsson and it is available for free here:
This article is recent, being published in 2009.
It is also systematic. A systematic meta-analysis looks at all the articles in a large database(s) that meet the inclusion criteria. According to the study’s authors: “We searched the Cochrane Library, Medline, Embase, Biological Abstracts, and PsycLIT. The last search included all trials published before 1 January 2008.”
Furthermore, it is published in a leading medical journal. According to wikipedia: “BMJ is considered to be one of the ‘core’ general medical journals; the others being the New England Journal of Medicine, (N Engl J Med), the JAMA, and The Lancet.”
The authors reached the following conclusions: “A small analgesic effect of acupuncture was found, which seems to lack clinical relevance and cannot be clearly distinguished from bias. Whether needling at acupuncture points, or at any site, reduces pain independently of the psychological impact of the treatment ritual is unclear.”
To sum up: acupuncture treatments for pain are not clinically significant, and they may not even be statistically significant, once bias is accounted for. That seems pretty damning to me.
Still not convinced? I knew you wouldn’t be. So I direct you to one of my favorite science bloggers, Orac, over at Respectful Insolence.
Orac is a medical doctor, and much more knowledgeable than me. In the above blog posts, he dissects a number of studies and meta-analyses. He testifies:
“When I first became interested in ‘alternative medicine’--excuse me, I mean ‘complementary and alternative medicine’ (
You should read his posts, or the articles he links to, and see if you aren’t equally converted.
Finally, here’s a press article to stew on:
It begins: “Ten years ago the [
Your tax dollars at work!
Sunday, June 28, 2009
Accommodationism II
Joshua Rosenau over at Thoughts from
Monday, June 15, 2009
Science's Claim to Truth
I see this on blogs now and again (I got on someone's case just the other day for saying it), and I think here's a place where a little simple philosophy can help the non-philosopher out.
1. First objection. If anyone's warranted in asserting certain matters of empirical fact, such as that chiropractic is bogus, scientists are. Some people are warranted in asserting such matters; therefore, scientists are. Anyone warranted in asserting that p is warranted in asserting that "p" is true, because "p" is true when and only when p. Therefore, scientists are warranted in asserting, for example, that it is true that chiropractic is bogus.
2. Second objection. To be warranted in asserting that p, one must know that p. This is why it is infelicitous to say "p, but I don't know whether p" (for example: "it's raining, but I don't know whether it is or not"). So if a scientist is ever warranted in asserting anything, she must know it. But scientists are sometimes warranted in asserting things; therefore scientists sometimes know things. But knowledge is factive: if S knows p, then "p" is true. So to be warranted in asserting something, it must be true; provided scientists know this (and if they didn't before, now they do), they may infer from the fact that their assertions are warranted that what they say is true.
3. Third objection. A standard scientific reasoning pattern is abduction. Thus, we argue from the correlation between a rise in man-made greenhouse gasses and a rise in global temperatures, to the best explanation: the conclusion that humans are causing global warming. But on equally good footing is the inference from "the evidence supports p" to "'p' is true"-- for what better explanation could there be of the evidence supporting p, than "p"s truth?
So there it is, blogospheric soldiers of science: lay your claims to truth.
Saturday, June 13, 2009
Accommodationism
The atheist blogs are abuzz with the accommodationist debate: are science and religion compatible, and if we think that they aren’t, ought we to say so? Jerry Coyne has a listing of all the main posts here:
1. Etiquette. Or as Forrest put it, “be nice.” Religion is a very private matter, and given that liberal religionists support church-state separation, we really have no business questioning their personal way of making meaning of the world. After all, they are not trying to force it on anybody else.
2. Diversity. There are so many religions out there, and so much variation even within particular sects or faiths. So why would we want to criticize liberal Christians, who have not sacrificed scientific accuracy, who are pro-evolution, when there are so many fundamentalists out there attacking science and trying to translate their beliefs into public policy?
3. Humility. Science can’t prove a negative: Saying there is no God is saying more than we can ever really know empirically, or based on data and evidence. So why drive a wedge between religious and non-religious defenders of evolution when it is not even possible to definitively prove the former wrong about metaphysics?
[Note, all three reasons are copied directly, and are not summaries of mine.]
I want to take these reasons in turn.
1. Etiquette. I don’t feel the force of this reason at all. Suppose I believe that accommodationism is false, and I base my belief on a certain array of reasons and evidence. If I write up my position and give my defenses, I will have criticized the accommodationists, because any criticism of accommodationism is ipso facto a criticism of accommodationists. So the “etiquette” principle entails I must shut up. But why should I have to shut up, while the accommodationists run around presenting their reasons and their evidence for the truth of accommodationism? That’s a sorry state for a public debate to be in, where one side is allowed to marshal its defenses and the other has to just be quiet and put up with it.
Maybe the alternative is that I’m allowed to present my case, but I must do it far away from where any accommodationist is, to avoid offense. But why? We’re told that “religion is a very private matter.” I don’t really know what that’s supposed to mean, but I imagine it’s something like: people cherish their religious beliefs, and are very upset when those beliefs are taken to task. If that’s what it means, then I can think of some other things that are very private matters: morality and well-being. But surely no-one thinks that we should just let the anti-abortionists, or the vaccine denialists and conspiracy theorists have the only say on those issues, because morality and well-being are “private matters.” And if religion is so freaking private and Ken Miller is after a “personal way of making meaning in the world” why does he have so many high profile books on accommodationism? This seems like nonsense.
Elsewhere Mooney &
2. Diversity. I find the claims under the “diversity” heading staggeringly silly. If you read Coyne’s
http://www.tnr.com/story_print.html?id=1e3851a3-bdf7-438a-ac2a-a5e381a70472
You’ll find that Coyne’s charge is precisely that the accommodationists do sacrifice scientific accuracy. He presents three specific charges (probably more, I haven’t read the piece for months): Miller-style accommodationism violates (a) the law of biology that says dead people don’t come back to life (b) the law of biology that says virgin births in mammals are impossible and (c) the (admittedly contestable) claim that human-like intelligent creatures are not inevitable products of evolution by natural selection. (a) is presumably necessary for natural selection at all, because death is the method of selection precisely because of its finality; (b) is a precondition of Fischer’s demonstration of the sex ratios; and (c), though it could be false, is certainly worth looking into and it would be absurd to suppress arguments for it on the grounds that otherwise Ken Miller is going to cry.
In fact, I don’t even know what Forrest and Mooney are thinking here. How could there be a scientific critique of accommodationism that wasn’t of the form: accommodationism sacrifices scientific accuracy?
3. Humility. Allow me to me non-humble for a moment, but what Forrest/ Mooney says here is literally stupid. Of course science can prove negatives. Here’s a go: it’s not the case that vaccines cause autism. Or, if negative existentials are your bag: it’s not the case that there exists matter at the top of a mercury barometer. Does Forrest think that it’s impossible to prove the existence of vacuums? Who is she, the Catholic Church circa 1200? What’s more, even in intuitionistic logic, you get the theorem: p → not-not-p, so a proof of anything is a proof of a negative. Suck on that!
I suspect the heart of the issue is that it’s not possible to prove the non-existence of God. But again, I think Forrest/ Mooney is trotting out methodological claims without thinking about them. It’s impossible to prove the non-existence of a deistic God; but one can certainly prove the non-existence of the accommodationist God. The accommodationist God by definition has causal traffickings with the physical world. He’s a watered down Christian God. I mean, Coyne’s whole point, again, is that science (in his opinion) tells against accommodationism. If it tells against accommodationism, it tells against the accommodationist God. Now, Coyne may be wrong in the end, but you don’t get that result for free by saying “humility.”
Just to head off one bit of criticism: yes, I know, I’ve been using “scientific proof” as a standard that delivers less than 100% credence, so it is always conceivable that accommodationism is true. But (a) if Coyne is right about the evidence, then this conceivability is on a par with, say, the conceivable propositions that the Flying Spaghetti Monster or the Invisible Pink Unicorn created the world; and (b) if Forrest/ Mooney is really saying we shouldn’t make scientific cases for claims we can’t establish beyond any doubt whatsoever, then they’re saying we shouldn’t make scientific cases at all.
OK, that’s the end. I’m sure all of these points have been made by posters and commenters elsewhere. But I plan to post more on accommodationism as the debate develops, and I thought a good first start was deconstructing this Forrest/ Mooney crap in detail.
P.S. Sorry I never got around to posting every Friday. This is difficult!