Specifically, the purpose of this post is to explain in simple terms the nature and purpose of homoeopathic dilution, or what homoeopaths are inclined to call "potencies". For many, of course, this is a matter of some humour, because homoeopathy is routinely ridiculed and rubbished by the skeptical and has been for over two hundred years. What homoeopaths call "potencies" the skeptical call "water". There are many excellent jokes on the subject. Here is one:
Readers will probably be aware of the reason for the mirth. Homoeopathic dilution - potentization - consists of diluting the original substance (usually a toxin) in graded steps, shaking or "succussing" the dilution at each step, until, at length, there is absolutely no trace of the original substance remaining. Undetettered by this physical fact, though, the homoeopath swears that he has made a "potency" of the original substance, the essence of which has somehow been imprinted upon the neutral medium of dilution (water or alcohol). The homoeopath calls it a "potency" and claims that it has curative properties - the rest of the world calls it "water" and claims that it is nothing more than quackery.
It is not our purpose here to mount a defence of the homoeopath's position, or to rehearse the evidence for the powers of homoeopathic dilutions, nor to rebutt the dreary predictability of the skeptics who have rattled on with the same objections ever since the days of Samuel Hahnemann, modern father of homoeopathic medicine. Instead, our single purpose is merely to clarify why it is exactly that homoeopaths make and use "potencies" and to elucidate for skeptic and believer alike the basis upon which a homoeopath selects a potency in any given case. There are many potencies that might be used. There are several different scales of dilution. The most common is the so-called C scale, whereby the original substance (tincture) is diluted by increments of 99 to 1 (centesimal). Others use a decimal scale of 9 drops of dilutant to one drop of tincture. Thus:
In any particular instance the homoeopath must select not only the medicine to be applied to the patient but also its potency. Such potencies are usually referred to as "low" or "high". A low potency means that only a few dilutions have been made. For example, a common low potency is called 6x. This means there have been six steps of dilution on the decimal scale. Similarly, 6c is regarded as a low potency on the centesimal scale. But often medicines (remedies) will be chosen at so-called "high" potency - 200c, for example, which is to say one drop to 99 has been taken and succussed (shaken) in two hundred steps. There are potencies as high as M, one million dilutions, CM, one hundred million, and so on. Generally, the point at which there ceases to be any physical substance remaining in a dilution is about 12c. Conventional science, therefore, supposes that all potencies "higher" than that are necessarily inert, and potencies as high as M or CM are simply ridiculous.
Practising homeopaths are sometimes divided on the question of potency. Some are low potency men and some reach for the high potencies and swear by their powers. Others will use low or high potencies according to various criteria and according to the perceived needs of a given case. Ever since the beginning of modern homoeopathy, though, the entire question of potency has never been very clear and has often been a cause for controversy and dispute. In some jurisdictions - such as France - the low potency advocates have been successful in getting high potencies banned by law. In other places, such as India, high potencies are the norm and low potency prescribing is deemed dangerous because low dilutions are still likely to contain traces of actual toxins that can harm patients. Homeopaths deal in very nasty substances: snake and spider venoms, toxic metals, poisonous plants. These toxins will still be active ingredients in low dilutions. Peddlers of low potency homoeopathy are condemned as reckless by their high potency colleagues.
Other questions arise too. Some homoeopaths suppose, for example, that high potency medicines act upon the mind while low potencies are centred upon the physical body. Some suppose that very high potencies act upon the spirit or soul - and it is here that homoeopathy, much to its detriment, adjoins spiritualism. Others suppose that certain potencies are suited to certain remedies. It is commonly held, for example, that white arsenic (Arsenicum album) is most potent at a dilution of 200c, or that the venom of the cobra (naja tripudians) is best at 30c. Still other practitioners select potency according to the so-called 'constitution' of the patient. A patient with a cold, sluggish constitution might require higher potencies than someone of a more sanguine and reactive temperament, for instance.
All of this, in fact, amounts to a certain degree of confusion. Indeed, no other aspect of homoeopathy causes more confusion and less agreement than the question of potency. In any given case, a dozen different homoeopaths might all agree upon which remedy is required, but none of them will agree on potency. Let us, therefore, try to set the matter straight. What is the guiding principle for selecting potency in homoeopathic medicine? When does one use low potencies and when does one use high potencies? What are the particular uses for particular potencies?
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The basis for selecting a homoeopathic remedy is much clearer. The basis is: similitude. Medicines are selected according to the similitude that exists between their known properties and the symptoms displayed by the patient. Belladonna poisoning, to cite a crude example, will include fever and dilated pupils. If a patient has these symptoms then the homoeopathic medicine is belladonna. The law of cure in homoeopathy is: like can cure like. That is the whole basis of homoeopathy, both ancient and modern. When a person is sick, the homeopath tries to find a substance (toxin) that will create similar symptoms in a healthy person upon the assumption that like can cure like. This is a much more defensible aspect of homoeopathy. The power of substances to cure the very symptoms they induce has been known since the ancient Greeks, at least. It is the issue of dilution and potency that invites the ridicule of skeptics. And, frankly, it is confusion on the question of potency, more than anything else, that has brought homoeopathy into wide disrepute. It is a matter than needs clarification.
Despite what its sundry critics propose - and indeed despite the fact that it often attracts the harebrained and the half-baked and deserves all the criticism it attracts - homeopathy is remarkably rational and systematic. It is one of the great ironies of our age that such a rational system of medicine, a product of the Enlightenment, has come to be associated with quackery and spiritualism. It is constructed from careful axioms and a systematic empiricism. The selection of potency, as much as the selection of remedy, is a matter of science. In fact, the two things are directly connected.
To understand, we need merely to realise what it was that led Hahnemann to dilute medicines in the first place. Because in the beginning he used raw tinctures. At first, experimenting with the principle like can cure like, he tried administering raw toxins to his patients. Not surprisingly, this made them sick. He therefore - very sensibly - started using smaller and smaller doses. Even so, however, he observed the following: if there was a near similitude between the patient's symptoms and the chosen remedy, even a small dose will aggravate the patient's condition before it begins to cure. Hahnemann observed aggravation. Thus, for example, belladonna might cure a patient with fever and diluted pupils, but before it cures it will aggravate. The more similar the toxin is to the symptoms of the patient the more the toxin will aggravate. Let us say that again: The more similar the toxin is to the symptoms of the patient the more the toxin will aggravate.
This is what led Hahnemann to experiment with succussed dilutions (potencies) - sometimes called Hahnemanian dilutions. He was looking for a way to avoid the effect of aggravation. There are, of course, degrees of similitude. Some types of fever are very similar to the fever typical of belladonna poisoning, other types of fever less so. Again: Hahnemann noted that the greater the degree of similitude, the more likely a toxin was likely to bring about a cure, but also the more likely it was to first aggravate the condition. Similitude is the principle of cure, but it is also the basis of aggravation. If you select a remedy the toxicology of which is very similar to the symptoms of a patient, then you have found an agent for cure, but that same agent will - for the same reason, namely similitude - aggravate. How do you retain the curative power but avoid aggravation? This is the problem that led Hahnemann to develop so-called "potencies".
The whole point of "potencies", that is to say, is to avoid aggravation. The objective, always, is to cure without aggravating. The greater the degree of similitude, the greater the danger of aggravation. This makes plain sense. If someone looks like they have belladonna poisoning and you give them ten drops of tincture of belladonna, you are going to multiply (aggravate) their symptoms: like plus like. Hahnemannian potency is an attempt to retain the curative effect of like can cure like but avoid aggravation. And this fact reveals the basis for selecting potency. That is, one selects whatever potency is likely to cure without aggravation. And in general, one selects the potency according to the degree of similitude. The greater the similitude, the higher the potency. Potency is not magic. Or spiritual. The whole purpose of potency is to avoid aggravation.
Homeopathy rests on this demonstrable foundation: the organism is super-sensitive to the similar remedy. If the homoeopath can locate a toxin that is very similar in its effects to the symptoms of the patient, then the patient will be super-sensitive to that toxin. If you have the symptoms of belladonna poisoning, you will be very sensitive to belladonna. Thus, very little of the similar remedy is needed. But conversely, only a small amount will trigger an aggravation. This is the art of choosing the potency. In any given case, the homoeopath must choose a potency that cures without aggravating. Too low a potency will aggravate. Too high a potency will either have no effect at all - other than placebo - or else will distort the symptom picture of the patient in question.
This is the guiding principle of homoeopathic potencies. The mistaken idea that high potencies are for mental symptoms arises from this, because - in most cases - mental symptoms will only be present where there is a high degree of similitude. Belladonna again: one of its mental symptoms is delirium. If delirium is present, as well as fever, and diluted pupils, then there is a deeper level of similitude between the patient's symptoms and the toxicology of the poison. In most cases mental symptoms, so-called, indicate a deep level of similitude. Thus mental symptoms typically call for higher potencies (in order to retain curative power but avoid aggravation.)
Whether or not this principle can be extended beyond the limits of physical substances into imponderable dilutions is another matter. Even if we concede that the organism is super-sensitive to the similar remedy, does this make it super-sensitive to a remedy in which not a single molecule of the original substance is present? This is the mystery of Hahnemannian dilution. Thus far, we must admit, the homoeopathic fraternity has not been able to provide a rationale for the action of such dilutions consistent with known physics. But at least we can be clear as to why it is homoeopaths use such dilutions: they are looking for a dose of the similar remedy that will be sufficiently large to cure but sufficiently small to avoid aggravation. It is unfortunate that homoeopaths are rarely clear about this important facet of their art.
Harper McAlpine Black