Astrology With New Eyes: The Telescope in Astrological Prognostication

Telescope observations and celestial novelties of the early seventeenth century impacted not only in astronomy and science but in many other fields of culture, philosophy, and art. But what consequences did the telescope have to astrology, the body of knowledge with the closest ties to astronomy? Curiously, very little research has been made on this topic and current opinion seems to assume that astrology continued to be practised following much of the same premises it had for the previous centuries. In this paper, we present evidence that suggests otherwise: a common astrological judgement of a solar eclipse in 1652 (Lisbon, Biblioteca da Ajuda, Cod. 49-III-20, no. 15a) which includes prognostications made by interpreting the appearance of Venus when observed through a telescope shows that at least some astrologers were not unaffected by the telescope and this, in our opinion, opens a new line of research.