Jacques Rohault (; 1618 – 27 December 1672) was a French

philosopher A philosopher is a person who practices or investigates philosophy. The term ''philosopher'' comes from the grc, φιλόσοφος, , translit=philosophos, meaning 'lover of wisdom'. The coining of the term has been attributed to the Greek th ...

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

and

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

, and a follower of

Cartesianism Cartesianism is the philosophical and scientific system of René Descartes and its subsequent development by other seventeenth century thinkers, most notably François Poullain de la Barre, Nicolas Malebranche and Baruch Spinoza. Descartes is of ...

Life

Rohault was born in

Amiens Amiens (English: or ; ; pcd, Anmien, or ) is a city and commune in northern France, located north of Paris and south-west of Lille. It is the capital of the Somme department in the region of Hauts-de-France. In 2021, the population of ...

, the son of a wealthy wine merchant, and educated in

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...

. Having grown up with the conventional scholastic philosophy of his day, he adopted and popularised the new

Cartesian physics ''The World'', also called ''Treatise on the Light'' (French title: ''Traité du monde et de la lumière''), is a book by René Descartes (1596–1650). Written between 1629 and 1633, it contains a nearly complete version of his philosophy, ...

. His Wednesday lectures in Paris became celebrated; they began in the 1650s, and attracted in particular

Pierre-Sylvain Régis Pierre Sylvain Régis (1632–1707) was a French Cartesianism, Cartesian philosopher and a prominent critic of Spinoza. Known as a philosopher, he was nominated to the French Academy of Sciences in 1699.''Science and social status: the members of ...

. Rohault died on December 27, 1672, in Paris.

Works

Rohault held to the

mechanical philosophy The mechanical philosophy is a form of natural philosophy which compares the universe to a large-scale mechanism (i.e. a machine). The mechanical philosophy is associated with the scientific revolution of early modern Europe. One of the first expos ...

, and gave qualified support to its "corpuscular" or atomic form of explanation, assuming that "small figured bodies" were the underlying physical reality. His ''Traité de physique'' (Paris, 1671) became a standard textbook for half a century. It followed the precedent set by

Henricus Regius Henricus Regius (; July 29, 1598 – February 19, 1679) was a Dutch philosopher, physician, and professor of medicine at the University of Utrecht from 1638. Biography Regius was born in Utrecht (city), Utrecht, and was also known by his birth na ...

in separating physics from

metaphysics Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...

. It also included the theory of

gravitation In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stron ...

Christiaan Huygens Christiaan Huygens, Lord of Zeelhem, ( , , ; also spelled Huyghens; la, Hugenius; 14 April 1629 – 8 July 1695) was a Dutch mathematician, physicist, engineer, astronomer, and inventor, who is regarded as one of the greatest scientists of ...

, given in terms of an experiment. The translation of

Samuel Clarke Samuel Clarke (11 October 1675 – 17 May 1729) was an English philosopher and Anglican cleric. He is considered the major British figure in philosophy between John Locke and George Berkeley. Early life and studies Clarke was born in Norwich, ...

(initially into Latin) gained an independent status, and numerous editions, through its annotations that purported to correct it with reference to the theories of

Isaac Newton Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a "natural philosopher"), widely recognised as one of the grea ...

. Rohault's experimental orientation remained popular, despite the criticisms of his theories. The ''Traité'' referred to a model of the eye that Rohault had worked on. A wide range of experiments used by Rohault included some mentioned by Descartes, and two well-known ones of

Blaise Pascal Blaise Pascal ( , , ; ; 19 June 1623 – 19 August 1662) was a French mathematician, physicist, inventor, philosopher, and Catholic Church, Catholic writer. He was a child prodigy who was educated by his father, a tax collector in Rouen. Pa ...

, but also others taken from medical men: Gaspard Asselli, Louis Gayant,

William Harvey William Harvey (1 April 1578 – 3 June 1657) was an English physician who made influential contributions in anatomy and physiology. He was the first known physician to describe completely, and in detail, the systemic circulation and proper ...

Jean Pecquet Jean Pecquet (9 May 1622, Dieppe, Seine-Maritime – 26 February 1674) was a French scientist. He studied the expansion of air, wrote on psychology, and is also known for investigating the thoracic duct. Furthermore, he studied the nature of visi ...

, and

Nicholas Steno Niels Steensen ( da, Niels Steensen; Latinized to ''Nicolaus Steno'' or ''Nicolaus Stenonius''; 1 January 1638 – 25 November 1686French philosophers French physicists 17th-century French mathematicians 1618 births 1672 deaths 17th-century philosophers French male non-fiction writers 17th-century French male writers {{france-physicist-stub