Saccheri, Giovanni Girolamo


1. Dates
Born: San Remo, Genoa, 5 Sept. 1667
Died: Milano, 25 Oct. 1733
Dateinfo: Dates Certain
Lifespan: 66

2. Father
Occupation: Lawyer

Giovanni Felice Saccheri was a notary.

No information on financial status.

3. Nationality
Birth: Italian
Career: Italian
Death: Italian

4. Education
Schooling: Religous Order, D.D.

He entered the Jesuit novitiate in Genoa in 1685. Sent to Milan in 1690, he studied philosophy and theology at the Jesuit College of Brera. Here he was influenced to study mathematics by Tommaso Ceva. As an ordained Jesuit professed of the fourth vow, he would have had a doctorate in theology.

5. Religion
Affiliation: Catholic

He entered the Jesuit novitiate in 1685, and was ordained a priest in 1694 at Como.

6. Scientific Disciplines
Primary: Mathematics
Subordinate: Mechanics

His two most important books, the Logica demonstrativa (1697), an explanation of logic more geometrico, and the Euclides ab omni naevo vindicatus (1733), were virtually forgotten until they were rescued from oblivion--the Euclides by E. Beltrami in 1889 and the Logica by G. Vailati in 1903. Much of his logical and mathematical reasoning has become part of mathematical logic and non-Euclidean geometry.

In 1708 he also published Neo-statica, a work in the tradition of peripatetic statics.

7. Means of Support
Primary: Academia, Church Life

1685-1690, taught at the Jesuit college in Genoa.

1694-1697, taught philosophy at Turin.

1697-1733, taught philosophy and theology at the Jesuit College of Pavia.

1699-1733, taught philosophy, then occupied the chair of mathematics in the University of Pavia (also called the Università Ticinese) until his death. Saccheri was appointed to this chair by the Senate of Milan.

8. Patronage
Types: Government Official, Aristrocrat, City Magistrate, Court Official

Saccheri dedicated his first book, Quaesita geometrica to Guzman, the governor of Milan.

He dedicated Logica demonstrativa, 1697, to Count Filippo Archintio, a Milanese senator.

He dedicated Neo-statica, 1708, and Euclides vindicatus, 1733, to the Senate of Milan, which had called him to the university chair.

Saccheri taught in Torino for three years and came to know Vittorio Amadeo II, Duke of Savoy, who called upon him many times for complicated calculations. Later, in 1713, the Duke tried to bring Saccheri back to Torino as a professor of mathematics. There is also a story that Vittorio Amadeo wanted to elevate Saccheri to a bishopric, but several sources deny the story, asserting that there is no evidence for it.

Venice also tried to bring Saccheri to Padua, to the very chair that Galileo had once filled.

In Milan Saccheri was welcomed into the Academia Claelia Vigilantium, organized by Countess Clelia Grillo-Borromeo, Gambarana mentions that during vacation periods at the university Saccheri spent his time in Milan with the Colleggio di Nobili.

In 1716 he arranged a celebration plus the inevitable volume of sycophancy in celebration of the birth of Prince Leopold.

9. Technological Involvement
Type: None

10. Scientific Societies
Memberships: None

One of his teachers at the Jesuit College of Brera was T. Ceva. Under Ceva's influence he published his first book, Quaesita geometrica (1693). Through Ceva he became a correspondent and friend of Giovanni Ceva and Viviani.

Sources
  1. P. Fr. Gambarana, S.J., "An Account of the Life of Girolamo Saccheri," in A.F. Emch, The logica demonstrativa of Girolamo Saccheri, Ph.D. diss., Harvard, 1934 (from a manuscript in Modena). A. Pascal, "Girolamo Saccheri nella vita e nelle opere," Giornale di matematica di Battaglini, 52 (1914), 229-51. QA2.I8G4 H. Bosmans, "Le Géometre Jérome Saccheri S.J.," Revue des questions scientifiques, 4th ser., 7 (1925), 401-30.
  2. Q2.R38
  3. E. Carruccio, "Saccheri," in Enciclopedia italiana di scienze, lettere ed arte, (Rome 1936), 30, 389-90.
  4. "Introduction," in G. Saccheri, Euclides vindicatus, ed. and tr.
  5. George B. Halsted, (Chicago, 1920).
  6. Carlos Sommervogel, ed. Bibliothèque de la Compagnie de Jésus, (Brussels, 1891), 7, 360-2.

Compiled by:
Richard S. Westfall
Department of History and Philosophy of Science
Indiana University

The Galileo Project Development Team
galileo@rice.edu

Non-Euclidean Geometry