In 1992, the definition of erectile dysfunction (ED) replaced the old term of impotence that had been used for many centuries, in order to avoid the general confusion existing until today in this field. In the past, the origin of impotence had been attributed to different causes such as psychological diseases, or witches and demons. In 1764, Fusanacci described impotence that can occur in the male as well as in the female, as a defect in reproduc-tion. The main causes responsible for impotence were identified as inability to achieve erection, a very fluid seminal ejaculation, a defective organ, dryness of testicles, and lack of copulative power after many sexual intercourses with healthy women. Some decades later in 1847, Beatty affirmed that one of the most remarkable changes that can be observed in the passage from childhood to maturity is the development of the sexual organs, followed by the appearance of new sensations. He distinguished impotence that occurs only in men from sterility that for him affects women, and divided the causes of impotence into 3 classes: organic, functional and moral (today defined as psychological). For Beatty, the progress of knowledge had taken away magic and sorcery from the human mind and now it was widespread only among the lowest and most ignorant classes of humble people. In this way, he shows the evolution of medical science in XIX century in accepting only the rational explanation of the human diseases.