A French Jesuit, Honoré Fabri studied theology at Lyon from 1632 to 1636. His main fields of interest were mathematics, physics, and astronomy. He engaged in a harsh controversy with Christiaan Huygens (1629-1695) about the structure of Saturn's system. In 1646, he moved to Rome, where he remained in close contact with Michelangelo Ricci (1619-1682). He corresponded with the Accademia del Cimento and prominent figures such as Gottfried Wilhelm Leibniz (1646-1716), René Descartes (1596-1650), and Marin Mersenne (1588-1648).