**Privat de Molières** was a French mathematician who argued against Newton in favour of Descartes.

- The Congregation of the Oratory of Jesus and Mary Immaculate, often called the Oratorians, was a Roman Catholic sect founded by Pierre de Bérulle in 1611 and approved by the Pope in 1613.
- Joseph studied at Oratorian schools in Aix, Marseilles, Arles and Angers.
- At the last of these schools he studied under Charles-René Reyneau from 1698 until 1699.
- However he had a deep love of science in general, and mathematics in particular, and in 1704 he went to Paris to take up a more active scientific career.
- He argued against Newton and for Descartes' view of physics although he knew Newton's to be the more precise.
- Of course, although we now accept Newton's ideas of gravitation without much thought, it is clear if one thinks about it for a while that the idea of action at a distance through a vacuum is absurd.
- Many around this time voiced such an opinion (Newton himself realised this was a weakness in his theories) but where Privat de Molières differed from other critics of Newton's theory of gravitation is that he attempted to make a mathematically sound theory based on the idea of vortices.
- Understanding the accuracy of the theory of gravitation, Privat attempted to bring Newton's calculations into the vortex theory of matter of Malebranche.
- The problem was Kepler's laws, easily explained by Newton, but the cause of real problems for Descartes' vortex theory of planetary motion.
- Fontenelle, the secretary of the Academy of Sciences, agreed with Privat de Molières.
- Privat de Molières published Lecons de mathematiques Ⓣ(Lessons of Mathematics) (1726), a work on the principles of algebra and calculus.
- His Lecons de physique, contenant les éléments de la physique déterminés par les seules lois des méchaniques Ⓣ(Physics Lessons, containing the physical elements determined by the laws of mechanical) (1734-1739), was a four volume work based on his lectures at the Collège Royal and contains details of the mathematical theory of his elastic "little vortices".
- He also published a series of Memoirs of the Academy and in several articles in the Journal de Trevoux.
- Privat de Molières was honoured by being elected to the Academy of Sciences in 1721, and became a Fellow of the Royal Society of London in 1729.

Born 1677, Tarascon, Bouches-du-Rhône, France. Died 12 May 1742, Paris, France.

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**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive