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Peletier, Jacques

1. Dates
Born: Le Mans, 25 July 1517
Died: Paris, July 1582
Dateinfo: Dates Certain
Lifespan: 65
2. Father
Occupation: Lawyer
His father was a prominent lawyer in Le Mans. His family was educated in theology, philosophy, and law. Peletier's family wanted him to pursue these same disciplines.
No explicit information on financial status.
3. Nationality
Birth: French
Career: French
Death: French
4. Education
Schooling: Paris, M.D.
Peletier went to Paris at a young age (1530) to study under the direction of his older brother Jean, a professor at the College of Navarre. He began studying law, but he completely abandoned this course of study at twenty-one in order to cultivate his studies of letters and philosophy. He was self taught in Greek and algebra.
Soon after he completed his Dialogue de l'orthografe, he became interested in medicine. In 1550 he began his studies in Poitiers and stayed subsequently in Bordeaux, Lyon, and Rome. He finally settled back in Paris where he received his licenciate in medicine (c. 1554).
5. Religion
Affiliation: Catholic
6. Scientific Disciplines
Primary: Mathematics
Subordinate: Medicine
From 1545-6, Peletier edited and annotated the Arithmeticae of Gemma Frisius for a Latin edition. His Arithmetic was reprinted without change six times in French, Italian and once again in Latin.
He left his position as head of the Collège de Bayeux to take up residence at the house of the printer Vascosan while he (Peletier) developed his project of reforming spelling according to pronunciation. This project culminated in a two volume work, Dialogue de l'orthografe (1550).
In 1554, he published a treatise on algebra inaugurating the use of literal symbols made popular later by Viète.
Many were hostile to his use of the vernacular in a scholarly work. Sixteen years later he had his revenge on his opposers when he published a Latin version of his Algebra with the ironical title, De occulta parte numerorum quam Algebram vocant.
Soon after the first printing of his vernacular algebra, Peletier began to study the foundations of geometry. In 1557 he published In Euclidis elementa demonstrationum in which he rejected the method of superposition.
He became embroiled in a lengthy dispute with Clavius over the angle of contact. A few months before his death he published his last contribution to the dispute, De contactu linearum. This controversy was settled nearly a century later by the mathematical work of Newton.
He did write a couple of works on medicine.
7. Means of Support
Primary: Academia, Patronage
Secondary: Medicine, Schoolmastering
After leaving school he became the private secretary to René du Bellay, Bishop of Le Mans. Through the influence of Bellay he received the position of tutor of mathematics at the Collège de Bayeux. By 1547 he was the head of this school.
After receiving his medical degree he became the physician to Marechal de Cosse as well as his mathematical advisor on fortifications. He may have been a tutor to Cosse's son.
During his travels and his studies of medicine he made a living as a surgeon and by tutoring in mathematics.
During the turmoils of the wars of religion, Peletier left Paris and traveled throughout France and to Italy. He became the head of the Collège de Bordeaux in 1572. After lengthy stays in Annecy and Savoy he returned to Paris in 1578 to become the head of the Collège de Le Mans.
There is no evidence that Peletier set up a private practice.
8. Patronage
Types: Eccesiastic Official, Aristrocrat, Court Official, Government Official
Through the influence of Bellay he obtained his postion at the Collège de Bayeux.
He was the personal physician to Marechal de Cosse.
By royal command he gave the funeral oration of Henry II from the pulpit of Notre-Dame.
He dedicated his Art poetique (1555) to Zacharie Guadart, the royal financial officer.
9. Technological Involvement
Types: Medical Practice, Military Engineering
10. Scientific Societies
Memberships: None
Among his friends were Pierre de Ronsard, the leader of the Pleiade. He shared with these seven poets a desire to create a French literature and to use the vernacular in wider scholarship. It is unclear whether Peletier became a member of this group.
  1. N.Z. Davis, "Sixteenth Century French Arithemetics on Business Life," Journal of the History of Ideas, 21 (1960), 18-48.
  2. AP2.J8
  3. C. Juge, Jacques Peletier du Mans, (Paris, 1907). PQ 1653.P6J9 V. Thebault, "A French Mathematician of the Sixteenth Century," Mathematics Magazine, 21 (1948), 147-50. QA1.N3
  4. J.A.Hazon, ed., Notice des hommes les plus celebres de la Faculté de Médecine en l'Université de Paris, (Paris 1778), pp.62-3.
  5. Maurice Thureau, "Jacques Peletier, mathematicien manceau au xvie siècle," La province du Maine, 2nd ser. 15 (1935), 149-60, 187-99.
Compiled by:
Richard S. Westfall
Department of History and Philosophy of Science
Indiana University

Note: the creators of the Galileo Project and this catalogue cannot answer email on geneological questions.

©1995 Al Van Helden
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