Connections between the Society of Jesus and astrology used to appear as unexpected at best. Astrology was never viewed favourably by the Church, especially in early modern times, and since Jesuits were strong defenders of Catholic orthodoxy, most historians assumed that their religious fervour would be matched by an equally strong rejection of astrology. This groundbreaking and compelling study brings to light new Jesuit scientific texts revealing a much more positive, practical, and nuanced attitude. What emerges forcefully is a totally new perspective into early modern Jesuit culture, science, and education, highlighting the element that has been long overlooked: astrology.