Homeopathic remedies come in small bottles, neatly labelled. Now consider this experiment. Remove the labels from the bottles and try to decide by an examination of their contents alone which label goes with which bottle. It turns out, in our present state of knowledge, that there is no way to do this.
But there is no mystery. Homeopathic remedies are prepared by diluting a mixture of water and another ingredient to the point that it is astronomically unlikely that even a single molecule of the original ingredient remains. What explains the fact that it is impossible to tell the solutions apart and sort them into bottles is that the solutions are the the same: water.
Now homeopaths are quick to notice that, as a matter of fact, while it is true that each vial contains water, each sample of water has a distinct history. Each is arrived about by diluting different substances. What differentiates the contents of the vials is their history.
There are roughly two ways historical facts can make a difference to what something is. Sometimes historical facts confer status. And status can be very important. A penny is legal tender only if it is produced with the right authority. An object might be physically the same as an ordinary penny and, yet, still not be a penny. Or suppose I am able to copy your signature perfectly. No one can tell the difference. This doesn't make my scrawlings your signature. In order for something to be your signature, it has to be made by you.
Historical differences of this sort are not physical differences and so they won't serve any role in explaining the uses to which the items in question can be put to work in physical transactions with other things. To suppose other wise is blank superstition. Only one of the pennies in my pocket used to belong to my son. But it would be silly to suppose that this fact would make a difference to what happens, say, when I put it in a coffee grinder. Or, to give a different example, one wine may be blessed and another not. For certain purposes this might be very important. But it is obviously not going to make a difference to the way we will digest these wines when we drink them.
The other way for historical differences to make a difference is by leaving a physical trace. The fact that the trespasser stood at a particular place in the garden is what explains the existence, shape, and size of the footprints we see there now. The footprint wouldn't have the properties it now has if not for the occurrence of certain historical events. The footprint itself is a trace of these events.
Homeopaths are interested in historically-based differences of the second kind. After all, homeopaths are precisely interested in understanding why it should be the case that different homeopathic solutions have different effects on people and also why homeopathic solutions differ in their effects from ordinary water.
Homeopaths believe that the water in their remedies contains a memory or a trace of the molecules they once contained, that the structure of the water has been physically altered by the past presence of molecules in just the way that the ground in my garden has been physically altered by the man who once stood there.
This brings us back to where we started. No science, no method, no technology now in existence can discern any intrinsic difference in the contents of the different vials. It's all just water.
Of course this doesn't mean that there are no differences. Perhaps our science is simply too immature. (Indeed, one prominent scientist, Luc Montagnier, has recently begun to investigate causal properties of supersolutions.)
But even if that is so, we now have a very good reason to doubt that taking drops of different homeopathic remedies could be causally efficacious in curing ailments. Why? Because we understand very well, there's no mystery, about how and why ingesting food and other substances acts on the body. This all takes place at the rather mundane and gross scale of molecules and metabolic processes. Even if there is a hitherto-yet-undiscovered difference between homeopathic remedies and water, it's hard to see how it could be the right kind of difference to make a difference to our bodies.
Now questions start to abound. If homeopathy works, it works thanks to causal processes operating at a level that no one alive now, or at any other time, comprehends. How likely is it that these unfathomable processes operate through the mechanism of ingestion of a few macroscopic drops out of brown vials straight out of central casting's nineteenth-century apothecary? This is really counterintuitive.
It weds good-old-fashioned cause and effect with, well, with mystery. And anyway, given that there is no way of telling the difference between a homeopathic solution and mere water, given that we don't yet have the science to do it, what evidence do practitioners of homeopathy have for thinking there are such differences? How did they figure it out?
In any case, this is all moot. While it would be wrong to say that there is no evidence of the effectiveness of homeopathy, there is no conclusive evidence that homeopathy is more effective than placebo. This is is exactly what you would expect given the fact that homeopathic solutions are water.
Homeopathy is a theory and a practice. I believe the theory is untrue; it is certainly unsupported. And homeopathic medicines are, as far as we now know, causally inert.
Question: Does this mean the practice itself is ineffective? I mean the homeopathic practice of providing care to those who need care? To answer this question, we need to think again.
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