Allopathy

Allopathy is a term, widely considered archaic, coined in the late 18th century by Samuel Hahnemann, a German physician and scholar who was the founder of homeopathy. Derived from the Greek (ἄλλος, állos, other, different + πάϑος, páthos, suffering), "allopathy" describes the Hippocratic principle contraria contrariis curantur:

Diseases which arise from repletion are cured by depletion; and those that arise from depletion are cured by repletion; and in general, diseases are cured by their contraries.

The term, of which a common variant was allopathic medicine, was meant to be contrasted to Hahnemann's own theory of "homeopathy", whose underlying concept was similia similibus curentur, "let like cure like", and was based on "the principle of similars". Allopathy, therefore, according to Hahnemann, because it was based on "the principle of opposites", was intended to characterize a wide range of medical theories and applications. The word "homeopathy", also Hahnemann's creation, which is in widespread use to this day, was derived from the Greek hómoios (similar) and páthos (suffering).

The term "allopathy" was used frequently throughout the first half of the 19th century, particularly in the United States, to describe various forms of conventional medicine, even by non-homeopathic practitioners themselves. In the last half of the 19th century, however, it came under attack for two reasons. Some of the criticism was by medical associations that saw it as a bludgeon to use against other health paradigms. Other criticism of its terms of describing medicine derived from the increasing use of scientific models of biology and treatment simply did not use a concept of opposites.

By the turn of the 20th century it had fallen into disrepute. Forty years later, during which time conventional medicine had begun to adopt a firmly scientific basis, the 1941 printing of the Encyclopedia Britannica, had, in its 23-volume set, a one-page article on homeopathy, 34 pages devoted to "Medicine" and "Medical" off-shoots, but no article at all about allopathy. Even its index, comprising an entire volume of 978 pages, made no mention of it.

Sir William Osler, first professor of medicine at Johns Hopkins, whose textbook of medicine is now in its 23rd edition, was quoted in the Flexner Report:

A new school of practitioners has arisen which cares nothing for homeopathy and still less for so-called allopathy. It seeks to study, rationally and scientifically, the action of drugs, old and new."(Flexner report, page 162)

The term, however, is still used occasionally today, generally in a disparaging fashion, by some practitioners of alternative medicine to characterize what others call conventional medicine. A reason that it is considered derogatory is that mainstream medicine is not based on a theory of opposites. In many cases, medical therapy either helps replaced a failed body system (e.g., administering insulin in Type I diabetes, when the body no longer makes its own), or with drugs to reduce the acquired insulin resistance of body cells in Type II diabetes. Many new therapies directly reinforce or regulate physiologic mechanisms operating at a molecular level.

One contemporary usage, which is not considered derogatory and respects historical tradition, is used to distinguish between U.S. osteopathic medical schools that grant the Doctor of Osteopathy (D.O.) degree versus "allopathic" medical schools that grant the degree Doctor of Medicine (Latin Medicinae doctorum, or M.D.). In the U.S., both types of medical schools are recognized as "mainstream"; the osteopathic schools teach additional musculoskeletal manipulations but the core curricula are otherwise identical. In the U.K., "osteopaths" are trained only in manipulations.