Honore Fabri

Honore Fabri

French mathematician, physicist and theologian
Country: France

Biography of Honoré Fabri

Honoré Fabri was a French mathematician, physicist, and theologian. He believed that as long as there was no irrefutable proof for the motion of the Earth, it should be condemned by the Church. However, if such proof was found, the clergy could argue that all passages in the Bible contradicting the doctrine of the Earth's motion should be understood figuratively. After joining the Jesuit order, Fabri became a professor of philosophy in Lyon and later served as a great confessor for the Roman Inquisition. Despite his caution, he became a defendant during his time as a member of the Inquisition, albeit for a short period.

During his career, Fabri published works in mathematics and physics. His notable work in mathematics includes the "Synopsis geometrica" (Lugduni, 1669), which was among the books used by Leibniz in his study of mathematics. In this book, Fabri replaced Cavalieri's method of indivisibles with progressive movements. In astronomy, Fabri gained recognition for his polemics against the discoveries of Huygens related to the planet Saturn. These polemics, which ended in Fabri's complete defeat, were published in the works of E. de Diyinis: "Brevis annotatio in Systema Saturnium Chr. Hugenii" (Rome, 1660) and "Septempedanus pro sua annotatione in Systema Saturnium Chr. Hugenii adversus ejusdem assertionem" (Rome, 1661). Both of these works, published under the name of Roman mechanic and optician Eustachio de Divini, were largely attributed to Fabri.

In the field of physics, Fabri authored the following works: "Synopsis optica" (Lugduni, 1667; translated into French), "Dialogi physici, in quibus de motu terrae disputatur; marini aestus nova causa proponitur…" (same location, 1669), and "Physica seu scientia rerum corporearum, in decem tractatus distributa" (same location, 1669). In the first of these works, the author provided a successful explanation for the blue color of the sky and also described and explained a visual illusion. Fabri explained the tides through the influence of the moon on atmospheric pressure, which in turn affects the sea.