Law of Similarity

The law of similarity has been observed since ancient times, but the first to study and clearly enunciate it was Hippocrates. He explained in his writing that there are two completely opposite ways to face diseases: the way of opposites and that of the similar, destroying the curative use of the toxic. Any substance that in its experiment on healthy subjects has caused the appearance of a given complex symptoms will be able to influence positively a similar set of symptoms, whatever its origin, producing an increase in defense mechanisms.

Hippocrates observed that medicine approaches treatment one of two ways, depending on objective observation of the signs of illness: that of the contrary, or “contraria contrariis curentur;” and, that of the similar, “similia similibus curentur.” Both are used as a motto of the ruling forces of nature, “Vis medicatrix naturae.” Hippocrates was the first to abandon mythological and pre-scientific concepts, introducing systematic observation and methodology to medicine, favoring the inductive method which parsed the particular to the general, from effects to causes, and from concrete facts to theoretical principles, challenging all the speculative theories.

In his text, “Places in Man,” he introduces this approach, differentiating from that of opposites and affirming the need to individualize treatment, devising a plan of therapy in response to those observations: “We would cure sometimes with the contraries, according to the nature and the origin of the disease. Sometimes with the similarity, again according to the nature and origin of the disease.” And also affirm, “Most parts of diseases are curable with the same cause that they have procured,” and, “The disease is produced from the similarity and through the similarities they produce, it can bring the sick back to health from the sickness.” So strangury treatment, which did not exist before, came into existence now, as the cough like strangulate, is caused by the same things.

However, in his book there are also traces of the pre-Hippocratic theories. Regardless, it’s evident in his writing that he had a remarkable capacity for observation of all natural phenomena.

Such premises make us clearly understand why, for example, in the treatment of freezing, we can use two opposite therapeutic techniques: the identical approach of rubbing the frozen body part with ice, or the opposite by applying heat. Similarly, in treatment of overheating, we can apply heat or cold. Both techniques are effective (all people who live in snow know and apply these techniques, and know that a hot drink or shower is a very effective means to treat overheating). But there is a fundamental difference between the two methods: the use of the contrary sees the body take such action passively, and the use of similarity creates an active reaction that persists well beyond the moment of the actual stimulus, and leads to significantly faster healing.

Obviously this reactivity of the body doesn’t happen only in thermal type stimulations; the reactive model is useful with all substances presented in nature, that is, every substance is capable of causing both toxic and perturbing effects, and both reactive and curative effects. But, while in the cold and heat example, we used the identical principle, in Homeopathy we use the substance that can induce in the body of healthy subjects symptoms most similar to those appearing in the diseases that we want to cure.

For what reason? The logic of the law of similarity is strict and clear: If the symptoms, as experience shows, are a sign of positive reaction in the body, the administration of substances that produce similar reactive symptoms will determine a strong acceleration towards healing.

The law of similarity is often used empirically, perhaps even unconsciously. For example, we can quote some healing practices used by the “curandero,” real wizards of the indigenous Mexicans. They were, in fact, using various types of herbs, in many cases exploiting the capacity of “anti,” but in others with the criteria of similarity.

Curiously, the source for these cases is the magazine Veterinary Science, no. 6 of November-December, 1987.

Reading the statement of the curators is almost laughable when it comes to showing obvious concerns about contradictions of certain cited phenomenon. Let’s read verbatim: “It’s not all clear. There are apparently contradictions between the known specific activities of some plants and the use made of it by the natives. For example “the Agave cupreata” is used as an antidote to snake poison, while from the performed study, it should contrarily increase the rate of absorption and enhance its activity to some poisons. The “Crotone dragon” that contains different irritant substances, is used instead with success as anti-diarrhea and anti-keratotic. The “Rose cabbage” is given a mild laxative action. On the contrary, containing certain proportion of tannin, it would be more logical to assume that it can be equipped with an astringent action (petals are used in infusion). The “Sida Acuta” traditionally used as anti-diarrhea contains alkaloid that should cause diarrhea.

It’s obvious that the writers of the article don’t understand Homeopathy. They cannot express more concern about the facts mentioned, while they are nothing more than a perfect application of the principle of similarity.

However, for such empirical applications, two fundamental principles are missing – those of dilution and succession. And we can’t talk about homeopathy without simply considering its effects as being due to herbal medicine.

By doing so, however, might there be a risk to seriously worsen the disturbed patient? Going back to the freezing example, if we continue to rub with ice for an indefinite time, we will get the opposite result of what we want, thereby delivering the subject to the so-called “white death.” Stimulations by way of similarity have to be minimal and measured, and for that reason, homeopathic substances are used in infinitesimal doses. Hahnemann used the technique of progressive dilution to avoid worsening of patients. This technique has remained unchanged since then.

It is important to consider the law of similarity in determining a course of treatment, with awareness of both advantages and disadvantages of the various approaches, and to design treatments in such a way that best serves the patient.