"You Can't Prove Homeopathy Doesn't Work"

The title is the repeated mantra of homeopathists (i.e homeopaths and their apologists). The point is that we don't have to: they are shifting the burden of proof.

They make the claim that homeopathy works, so the burden of proof is upon them. Until then, as the late Christopher Hitchens put it, "That which is asserted without evidence may be dismissed without evidence."

I can only assume that homeopathists are ignorant of how proof of efficacy works.  This is not written for those people (even if they do understand it, they will likely pretend not to), but for open-minded people who are not aware of this. (This lack of awareness is not entirely surprising, given that this is not the sort of thing that is taught in school unless one is studying statistics, at A level in the UK, and probably a similar level elsewhere.) What follows is somewhat over-simplified, but serves to illustrate the point it seeks to make.

When one conducts a scientific test, one needs what are called "controls"; the purpose of these is to ensure that any changing observations are due to the parameter that the experimenter is changing. When testing pharmacologically active compounds for potential use as medicines, if it is ethical to do so the control usually takes the form of a placebo.

You may have encountered the saying that "you can't prove a negative". For this reason, the test takes the form of disproving a negative. The experimenter formulates what is called the "null hypothesis" (the negative). This takes the form of a testable statement of the form: "There is no statistical difference at a significance level of [p-value given] between [test substance] and placebo in their effect on [specify condition being tested]." (NB: Significance testing and "p-values" are minefields that are poorly understood by most people. If you are interested in why, there is a superb article on this on the Royal Society's website.)

The tests are then conducted, adhering to experimental protocols that are established before the test is conducted and should include "blinding" (neither the experimenter nor the test subjects know if the latter are being given the placebo or the test substance) and "randomising" (the selection of the control group is random in order to prevent bias). This adherence to protocols means that, for example, if you are testing something for its analgesic properties and you suspect from the outcomes that it may have, say, antihypertensive effects, you must design a new test for the antihypertensive effects.

A key point is that the experiment determines whether or not the null hypothesis (i.e. the statement that there is no statistical difference) is refuted. The outcome is binary, i.e. there are exactly two possible outcomes: either the null hypothesis is refuted or it isn't refuted. There are no other possibilities. If the null hypothesis is refuted, the test is deemed positive for the test substance. Otherwise, the test is deemed to be negative. There are no intermediate states such as the "inconclusive" one so beloved of quacks; what they term "inconclusive" is what honest researchers call "negative".

The test is then written up in detail and published to enable other scientists to evaluate and replicate it (outcomes that can't be replicated aren't a lot of use!).

Another key point is that the burden of proof of a claim is placed where it belongs, i.e. it is for the person who claims that a substance is efficacious to prove it, not for others to disprove the claim. The touts for homeopathy do not like this, but this simple fact remains:

There is no such thing as an independently replicated robust-quality double-blinded randomised control trial that demonstrates that homeopathy is distinguishable from placebo for any condition or purpose.

 

So how can we be sure that it doesn't work?

First of all, homeopathy is not medicine. It is a marketing tool for pseudomedicine that pretends that magic is real and relies upon the gullibility of the people whom its practitioners cynically target in the cause of profit.

It is made by serial dilution of an original substance (“mother tincture”) and “succussion”, i.e banging it against a resilient surface (the inventor, Hahneman, reputedly used a leather-bound Bible). This banging, we are told, transfers the “essence” (or “vitality”, depending on which homeopath is quacking) of the original substance to the solvent. Nobody seems to be able to tell you how many bangs are necessary for this magic to occur.

In the homeopathic “C” scale, each dilution is 1 part of “magic” per 100 parts of solvent, so by the time you get to 30C, the dilution is 1 part per 10⁶⁰ parts of solvent. There are several problems with this:

• The solvent would also dissolve minuscule amounts of the containing vessel; hence, if this was a glass vial, borosilicate glass would be dissolved. For some unexplainable reason, the “magic essence” from the borosilicate is selectively excluded from being transferred to the solvent.
• Back to the 10⁶⁰: if a sphere the size of Earth’s orbit around the Sun was filled with water, it would contain “only” 4.25x10⁴⁹ molecules, i.e. in a sphere that big containing the homeopathic “remedy”, there would be less than a 1:10,000,000,000 chance of a single molecule of the original substance existing.

We are then invited to suspend our critical faculties and believe that further serial dilution and succussion makes the substance more potent. The 30C dilution previously mentioned is referred to, by homeopaths, as a “low potency”. Something like the flu remedy touted by Boiron (a multi-million pound/dollar/euro manufacturer of this implausible magic) is what the homeopaths call “high potency”: 200C, ie a concentration of 1 part per 10⁴⁰⁰ . Given that there are only about 10⁸⁰ atoms in the known Universe, you would need 100,000 Universes to have a probability of one molecule of the original substance existing!

Obviously, this is nonsense. Nothing can be diluted even as far as the “low potency” 30C level. The homeopaths try to get around that by pretending that water in the solvent has a magic memory of what has been dissolved in it. Somehow this memory is very selective: it remembers only the stuff the homeopaths wants it to remember and selectively forgets all the other stuff that it has dissolved in it (so-called “pure” water is never actually 100% pure). Remember the borosilicate! Anyone who believes this guff cannot possibly have a brain, but merely skull-water with the memory of a brain.

One of the apologists for homeopathy that regularly posts on Quora states that this water memory phenomenon was endorsed by winner of the Nobel prize for Physics, Prof. Brian Josephson, FRS. It was, but what the apologist neglects to tell us is that Josephson did not actually study it, but merely attended a lecture given by a proponent of the water-memory hypothesis, Jacques Benveniste, who published a paper on the subject in Nature. When corroboration was sought, it could not be found and neither Benveniste nor anyone else has been able to replicate it.

A very short duration “water memory” phenomenon does appear to exist, but it endures for only a few femtoseconds.

Water memory of the type proposed by homeopaths exists only in the homeopaths’ own deceptions (and delusions?).

Could there be some other explanation? Homeopaths claim any number of things, almost always from a position of profound ignorance of the science involved, ranging from quantum mechanics, through some as-yet undetectable “energy”, to an unknown mode of operation unknown to science (or anything else, for that matter). They can produce no evidence, or even a plausible scenario, for any of these things.

For homeopathy to work, most of what we know about chemistry and physics, including the bits that enable me to post this blog and you to read it, would have to be wrong: if homeopathy was plausible, the modern world could not exist. 

 

So why do some people believe in this stuff?

I contend that there are three main things that contribute to the anti-scientific magical-thinking belief that homeopathy works:

1. The disinformation and dishonest marketing ploys used by the touts for homeopathy.
2. A combination of human credulity/gullibility and the failure of science education to adequately counter this.
3. A phenomenon whereby people tend to credit the last “remedy” or “treatment” they took for the “cure” (aka the post hoc ergo propter hoc fallacy). If, for example, somebody is taking medicine for a condition, but does not seem to improve, but then tries a pseudomedical intervention like homeopathy and seems to improve, they attribute the improvement to homeopathy and not to the possibility that the medicine takes a while to work. Similar phenomenon with self-limiting conditions.

This explains why the "skill" of a "good" homeopath lies in "treating" self-limiting (or, better, non-existent) ailments with nothing. For profit. Then you have the other kind of homeopath. These will pretend to be able to treat anything from malaria to autism to cancer with nothing. For profit.

It's worth repeating:

There is no such thing as an independently replicated robust-quality double-blinded randomised control trial that demonstrates that homeopathy is distinguishable from placebo for any condition or purpose.