Marin Mersenne (September 8, 1588 - September 1, 1648) was a French theologian, philosopher, and mathematician. He is best known amongst mathematicians for his search for a formula to generate prime numbers, based on what are now known as "Mersenne numbers." However, he was also influential in publicizing and disseminating the work of some of the greatest thinkers of his age.
He studied at Le Mans and at the Jesuit College of La Flèche, where he formed a lifelong friendship with Descartes, who was a fellow student. After his studies, Mersenne was sent to Nevers as professor of philosophy, between 1614 and 1620, where after he returned to Paris.
His first publications were theological and polemical studies against Atheism and Scepticism, but later, he devoted his time almost exclusively to science, and published a number of works on mathematics.
His chief claim to fame, however, is the encouragement which he gave to fellow scientists of his time. He took an active interest in their work, often making, or asking, stimulating suggestions and questions. He counted Gassendi and Galileo amongst his friends; and it was Mersenne who reined in Descartes from his free and dissipated life, bringing him back to more serious pursuits and directing him towards the study of philosophy.
However, the attacks against Descartes' Meditations aroused Mersenne's suspicions for a time; but Descartes' answers to his critics restored Mersenne's faith in his friend's orthodoxy and sincere Christian spirit.
Mersenne also requested that, after his death, an autopsy be performed on his body, thus making sure he served science until the very end.
- "Quæstiones celeberrimæ in Genesim" (Paris, 1623), treatise against Atheists and Deists; only a part has been published, the rest still in manuscript form
- "L'impiété des déistes et des plus subtils libertins découverte et réfutée par raisons de théologie et de philosophie" (Paris, 1624); "La vérité des sciences contre les sceptiques et les pyrrhoniens" (Paris, 1625);
- "Questions theólogiques, physiques, morales et mathématiques" (Paris, 1634);
- "Questions inouïes, ou récréations des savants" (Paris, 1634);
- Les mécaniques de Galilée" (Paris, 1634);
- "Harmonie universelle, contenant la théorie et la pratique de la musique" (Paris, 1936-7);
- "Nouvelles découvertes de Galilée", and "Nouvelles pensées de Galilée sur les mécaniques" (Paris, 1639), both translations;
- "Cogitata physico-mathematica" (Paris, 1644);
- "Euclidis elementorum libri, Apollonii Pergæ conica,Sereni de sectione coni, etc." (Paris, 1626);
- "Universægeometriæ mixtæque mathematicæ synopsis" (Paris, 1644).