Il medico "mago" e il suo pubblico: Galeno tra prognosi e divinazione

The paper aims, at first, to provide a synoptical view on the practice of prognosis, and on its methodological status, according to Galen's works. Then the author, analyzing a selection of texts coming from the galenic corpus, tries to throw light on Galen's point of view about the relationship between prognosis and divination. Both these technai aim at forecasting the future but, according to Galen, only one of them -prognosis, of course- is able to provide accurate information about the patient's health, and a reliable prediction of the future outcome of a certain disease. That's why the physician has to be careful when he pronounces a prognosis, since ignorant people may confusse his predictions with those made by the diviners, which are commonly known with the Greek word manteiai: this could result in a loss of credibility by the physician. But, in some cases, says, Galen, pronouncing a sensational prognosis -though based on evidence obtained by the observation of the symptoms- could give to the physician the opportunity to impress the crowds and gain popularity and prestige.