The notion and the linguistic coinage of “errore popolare” is not as old as it is commonly believed, but comes from the history of medicine when in the late 16th Century, the Sorbonne’s professors labelled as “erreur populaire” the paracelsian therapies. The definition became common in Italy and England. Another area where the idea of “errore popolare” was widespread is that of religion, where the notion of “error” borders with that of heresy, superstition and magic. However, the “scientific revolution” did not identify the mistakes with a social class or discipline but in the way knowledge was acquired: only the criteria of proof and evidence dispelled erroneous notions. Thus the “scientific knowledge” discredited the beliefs of the ancients, considered to be their major source, and confined them the sphere of imagination which was to be highly appreciated in the Romantic age. Such a change in perception and evaluation was favored by the new vision of the popular culture, folklore, seen as an autonomous cultural system.