Aphorism 21 to 30

1 The short duration of the action of the artificial morbific forces, which we term medicines, makes it possible that, although they are stronger than the natural diseases, they can yet be much more easily overcome by the vital force than can the weaker natural diseases, which solely in consequence of the longer, generally lifelong, duration of their action (psora, syphilis, sycosis), can never be vanquished and extinguished by it alone, until the physician affects the vital force in a stronger manner by an agent that produces a disease very similar, but stronger to wit a homoeopathic medicine. The cures of diseases of many years’ duration (ยง 46), by the occurrence of smallpox and measles (both of which run a course of only a few weeks), are processes of a similar character.

Samuel Hahnemann
Samuel Hahnemann (1755-1843) was the founder of Homoeopathy. He is called the Father of Experimental Pharmacology because he was the first physician to prepare medicines in a specialized way; proving them on healthy human beings, to determine how the medicines acted to cure diseases.

Hahnemann's three major publications chart the development of homeopathy. In the Organon of Medicine, we see the fundamentals laid out. Materia Medica Pura records the exact symptoms of the remedy provings. In his book, The Chronic Diseases, Their Peculiar Nature and Their Homoeopathic Cure, he showed us how natural diseases become chronic in nature when suppressed by improper treatment.