Studies using macrophages treated with different homeopathic medicines resulted in a significant increase in the ratio of activated / resident macrophages compared to control (water, hydroalcoholic and untreated) groups. Different macrophage receptors have been altered in both expression and distribution, as well as altering the production and release of different cytokines and reactive products derived from oxygen and nitrogen. And this is simply amazing if we remember two important things: 1) the treatment that most altered was usually in a great power, that is, highly diluted, type Belladona 200c; distilled water that once came in contact with a substance and which, at present, we detect nothing inside. 2) Macrophages are immune cells present in all tissues and organs, including the central nervous system, responsible for organic homeostasis. In Hahnemann’s day, none of this was known, which makes the discovery of homeopathy even more incredible, for we can easily call this quest for homeostasis, this quest for balance, “life force.” A good doctor, with a good capacity for observation, with much knowledge, and some genius, was Christian Friedrich Samuel Hahnemann (1755 – 1843).