Throughout most of its history, astrology was considered a scholarly tradition. It was accepted in political and academic contexts, and was connected with other studies, such as astronomy, alchemy, meteorology, and medicine. The zenith of Astrology took place between the 15th and 16th centuries, renaissance scholars such as John Dee, Michael Nostradamus, Johannes Kepler and Galileo Galilei were all also astrologers predicting events, and advising diagnosing and prescribing for physical or mental illnesses. This underpinned a system in which people, the world, and the universe, were understood to be interconnected.  Astrology co-existed with the principles and practices related to mythology, magic, religion, and spirituality. At the end of the 17th century, new scientific concepts in astronomy and physics advanced by Isaac Newton called astrology into question, however astrology continued into the 18th century in almanacks and chapbooks.