Reader “Pragmatic” left the following comment on my recent homeopathy entry and I wanted to respond to it because it is very typical of what I hear from homeopaths to defend their “craft”. A decent response would be long enough for a blog entry in itself, so that’s what I did.

Steve (and all), I very well understand your feeling that “homeopathic theory makes no sense and is not even internally consistent.” I remember those feelings well from my early days (and years) as a homeopathic patient, and then as a homeopathy student. (I am now a friends-and-family practitioner.) But I persisted because over and over I saw it work, in some cases for conditions for which “everything else” had already failed. (Hay fever and other allergy; mental imbalance; behavior disorders; ADD; and a raft of more trivial complaints.)

As to the (apparent) lack of internal consistency, that is similar to the (apparent) lack of internal consistency in the field of physics, where different rules, observations, outcomes and etc. apply under different circumstances, and to different purposes (e.g. Newtonian versus quantum laws). In other words, what first appears to be “lack of internal consistency” turns out instead to be complexity, and the difficulty of learning enough of “the whole picture” to give useful context. In both cases, tho the connections are not immediately apparent, they are learnable.

The first point is the most common one I have personally heard from the users of homeopathy, “I have seen it work.” Of course, this is an appeal to anecdotal evidence. Humans are social storytelling animals – we instinctively learn by the experience of others. Ogg teased a saber-toothed tiger and the tiger ate him – lesson: don’t tease tigers (or perhaps one shouldn’t tease any vicious carnivore). This story is much more compelling than an abstract discussion of the tendency of carnivores to respond violently to provocation.

Further, the most compelling stories are our own. When we believe we have experienced something directly, it is difficult to impossible to convince people otherwise. It’s just the way humans are hardwired.

Understanding the world through stories was a good strategy in the environment of our evolutionary history but is far too flawed to deal with the complex world we live in today. In fact, the discipline of science developed as a tool to go beyond the efficient but flawed techniques we evolved. Perhaps, for example, saber-toothed tigers were generally lazy and not easy to provoke, but Ogg teased the tiger by throwing a stone at it and accidentally hit it in the gonads. Oggs friends were probably (statistically speaking) still better off just assuming it is a bad idea to tease tigers. Evolutionary pressures favored a more simplistic approach to nature, one that tended to assume that apparent patterns were real.

Now fast forward a few hundred thousand or few million year to modern society. We are confronted with a dizzying array of apparent patterns and using the simple rules of thumb we evolved to deal with them are not adequate. Whether or not a treatment works for a symptom or disease is a good example. Symptoms tend to vary over time, some may spontaneously remit, and our perceptions of symptoms are susceptible to a host of psychological factors. There are also numerous biological factors that may have an effect. If we are to make reliable decisions about the effects of specific interventions on symptoms and diseases we will need to do better than uncontrolled observation, or anecdotes.

We also have history to inform our opinions about anecdotes. Western practitioners relied upon the humoral theory of health and illness for thousands of years. Apparently thousands of years of anecdotal experience did not inform them that their treatments were worthless or harmful. Dr. Abrams became wealthy by selling a machine to diagnosis and treats ailments. His devices were widely used, with millions of people swearing by their effectiveness. It worked for them, and their experience was unshakable. When Abrams died it was discovered that his machines (previously protected from inspection) were filled with useless random machine parts. At the turn of the century radioactive tonics were popular, until prominent proponents began seeing the ill effects of radiation poisoning.

The point of these examples is that anecdotal evidence led many people to conclude that these interventions worked. They are useful examples because they are no longer accepted, humoral theory was replaced by scientific medicine, Abrams devices were dramatically exposed, and radiation therapy is directly harmful. But for treatments that are not directly harmful (and least not in an obvious way) or where there is no “man behind the curtain” to expose dramatically, all we have are the anecdotes – and clearly they are not reliable.

Even in mainstream medicine we have learned to distrust anecdotal evidence, even our own. The history of medicine is strewn with treatments that seemed to work but then were abandoned when scientific evidence showed otherwise. The classic example of this is mamillary artery bypass for cardiac angina – it seemed anecdotally to work, but it didn’t.

Also, if proponents of homeopathy believe the treatments work then they have the burden of answering why they don’t work when properly studied. I have covered the usual excuses in my previous post, but the fact is two centuries of research has failed to show a convincing or consistent effect – to show that homeopathy works for anything.

The second part of Pragmatic’s question is a false analogy between how science explored the unknown and plausibility arguments. The premise we agree upon is that science currently does not have an explanation for how homeopathy might work. Pragmatic argues that we should not conclude that homeopathy therefore is impossible but rather that we simply do not yet understand how it works. But this argument misses the big picture and misrepresents science.

Scientific exploration does indeed begin with an anomaly – something we don’t understand. Resolving anomalies is the bread and butter of science. We certainly don’t just declare any apparent anomaly impossible, or pretend that we can or should be able to explain everything. But there are two primary things to consider when confronted with an apparent anomaly:

1 – First and foremost – how sure are we that the anomaly exists. Too often I see those promoting paranormal beliefs (and I include homeopathy in this) looking for explanations for an apparent anomaly before they have proven that the anomaly exists. Step 1 is to prove an anomaly. With regard to homeopathy, this means convincingly showing that homeopathy does in fact work – or even that there is any difference among homeopathic preparations and regular water. Homeopathy proponents have failed to do this. So, at the present time there is no anomaly to explain.

2 – How big an anomaly is it? Not all anomalies are created equal. If an observation does not fit in some details with the current model, that is great. That’s an opportunity to figure out something new. Scientists confront minor anomalies every day. Moderate anomalies are increasingly rare as we learn more about nature, but they are still there and they garner a great deal of attention from scientists as great “mysteries.” But major anomalies, ones that would violate well-established laws of nature, are almost non-existent. I am not talking about the known limits of our current models, but something akin to violating the law of conservation of energy. At the very least the claim of a major anomaly should require equally major evidence – the weight of the evidence should be proportional to the weight of the anomaly. What we have with homeopathy is very weak and sloppy evidence and a seriously major apparent anomaly. Occam’s razor favors the conclusion that the anomaly does not exist. (Hey, but I could be convinced otherwise – with solid evidence, not anecdotes).

And also I would point out that Pragmatic’s interpretation of “lack of internal consistency” as meaning “anomalous phenomenon” is not actually what I meant. I meant that homeopathy states that like cure like, but then also states that remedies have to fit the person, not the symptom. There is no theoretical way to resolve this inconsistency. They also claim dramatic anecdotal evidence for effectiveness but then excuse the lack of a dramatic effect in clinical trials. So homeopathy is dramatic in uncontrolled situations but subtle under controlled observations. And they say that homeopathic preparation increases the “memory” of some substances in water or ethanol, but not others, without reason.

In conclusion, the current generation of homeopathy enthusiasts (and this was very apparent at the recent forum) are acting as if the question of homeopathy was never seriously considered before. Pragmatic characterized the mechanism of homeopathy as “not immediately apparent.” But the fact is that homeopathy is two centuries old. The battles that are being fought now were fought over a century ago – and the homeopaths lost. They lost because as science progressed it moved farther and farther away from the precepts of homeopathy, and homeopaths consistently failed to show that their ideas were correct or their treatments worked. As science progresses it is moving farther from homeopathy’s claims, not closer.

Homeopaths lost the scientific debate well over a century ago, but they won’t give up, and each new generation wants to have the debate anew. It’s over. You lost. Accept it and move on – the rest of us have.