The **Marquis de Condorcet**'s most important work was on probability and the philosophy of mathematics.

- His parents were Jean Pierre Antoine Caritat de Condorcet (1702-1743) and Marie Madeleine Catherine Gaudry (1710-1784).
- Antoine Caritat de Condorcet was a military man and was captain of the Barbançon regiment.
- She continued to dress Condorcet as a baby in white dresses until he was eight years old.
- He was kept away from others and denied the exercise and open air play that young boys would enjoy.
- In 1754 Condorcet entered the Jesuit College in Reims where he spent four years.
- In 1758 Condorcet entered the Collège de Navarre in Paris which had a high academic reputation.
- A recent development had been in 1753 when Jean-Antoine Nollet (1700-1770) had been appointed as the first professor of experimental physics and had taught in a specially constructed lecture theatre for 600 students.
- Georges Girault de Kéroudou taught mathematics and philosophy at the Collège de Navarre and he gave Condorcet a passion for mathematics so, when he graduated from the Collège de Navarre in 1760, he was determined to pursue a career in mathematics.
- In 1762 Condorcet left his home in Ribemont and went to Paris where he lived with Georges Girault de Kéroudou who had taught him mathematics at the Collège de Navarre.
- Condorcet lived in a small attic above Girault de Kéroudou's home on the rue de Jacob in central Paris, close to the University.
- Jeanne Julie Éléonore de Lespinasse (1732-1776), who ran a salon in Paris and became famed as a letter writer, was a close friend of Jean le Rond d'Alembert and she got to know Condorcet well at this time.
- We leave the reader to judge how much of his manner at the time was a result of his very protective upbringing.
- Condorcet was now undertaking research on the integral calculus and he produced a memoir which was refereed by Alexis Claude Clairaut and Alexis Fontaine.
- They saw much potential in the young Condorcet, but rejected the paper with, however, encouragement and advice on how he should proceed.
- In 1765 Condorcet's memoir Essai sur le calcul intégral Ⓣ(Essay on the integral calculus) was submitted to the Académie des Sciences and refereed by d'Alembert and Étienne Bézout who reported positively on 22 May 1765.
- He fully resolves this general problem: "Given a differential equation of a given order, which contains as many variables as one wishes, determine whether this equation, in the state in which it is proposed, admits, or does not admit, an integral of an immediately lower degree." The solution he gives of this problem, in addition to having the merit of utility, has the merit of elegance and of generality.
- The work announces the greatest talents, and those most worthy of being stimulated by the approval of the Academy.
- In the acknowledgements he thanks Alexis Fontaine for his "kindness to communicate to me, before the printing of his Memoirs, the fundamental Theorem which is found there on page 24." He also notes connections of his work on difference equations to results of d'Alembert in his memoir Recherches sur Differens Points Importans du Systeme du Monde Ⓣ(Research on different important points of the world system) (1754-56) and to Euler in his Institutions Calculi Differentialis Ⓣ(Differential calculus methods) (1755).
- As a result of this memoir and a series of other mathematics papers he published at this time, Condorcet was elected to the Académie des Sciences in 1769.
- Around this time he was a frequent visitor to Julie de Lespinasse's salon which she had opened on the rue de Belle Chasse in 1764.
- Condorcet would have deep mathematical discussions with d'Alembert who was living in Julie de Lespinasse's salon.
- However, here is a new application of these series, more important, in my opinion, than any that we have already made.
- Soon after the publication of his 1772 work, Condorcet met Anne Robert Jacques Turgot (1727-1781), a French economist, in Julie de Lespinasse's salon.
- Turgot had become an administrator under Louis XV and was appointed Controller General of Finances in August 1774 under Louis XVI.
- In the year he was appointed, he had Condorcet appointed Inspector General of the Mint.
- This marks a major change in direction in Condorcet's career.
- Turgot was dismissed from his post in 1776 and Condorcet tended his resignation in support.
- Condorcet's resignation, however, was refused and he continued to fill this post until 1791.
- In 1777 Condorcet was appointed Secretary of the Académie des Sciences.
- He had been advised by Voltaire and by d'Alembert to become an expert in writing obituaries in order to improve his chances of getting the post.
- His most important work was on probability and the philosophy of mathematics, especially his treatise Essay on the Application of Analysis to the Probability of Majority Decisions (1785).
- He presented it as an attempt to demonstrate the applicability of calculation to "questions of interest for common utility".
- It was concerned explicitly, as Condorcet explains at the beginning of the introduction, with the practice, widespread since antiquity, of submitting all individuals to the will of the greatest number.
- It was also concerned with the differences between ancient and modem constitutions to which Condorcet returned throughout the rest of his life ...
- The justification for majority voting in the ancient constitutions, Condorcet wrote in the 'Essai', was associated with "the words 'freedom' and 'utility'," more than with '''truth' and 'justice'." ...
- Condorcet makes clear, in the introduction to the 'Essai', that the decisions to be made in modem constitutions are about important social questions, including economic policy.
- Also in 1786 he again worked on his ideas for the differential and integral calculus, giving a new treatment of infinitesimals.
- The two met through their common interest in the defence of three peasant victims of judicial error and legal abuse ...
- Condorcet championed the liberal cause, he was elected as the Paris representative in the Legislative Assembly and he became the secretary of the Assembly.
- Sexual and gender differences are either the product of education and socialisation - and therefore subject to change - or they are simply irrelevant to a discussion of natural rights.
- The first category includes the different spheres of activity (public versus private) to which men and women have traditionally applied their intellect, as well as their allegedly different senses of morality or justice.
- Women, it has been said, are guided by their feelings rather than by their reason or conscience.
- He joined the moderate Girondists and argued strongly that the King's life should be spared.
- But these are not the only reasons why the 'Tableau général' Ⓣ(General table) is difficult to read: editorial blemishes were added to those contained in the manuscript, especially in the first edition.
- In that respect, although the 'Tableau général' is indeed a blueprint for future work, it also constitutes a methodological synthesis of earlier researches.
- Retrospectively, one can imagine how much care Condorcet would have given to correcting and completing the 'Tableau général' had he had sufficient time for it.
- In no case can it be considered as a contingent work which he would have "taken lightly." Why did he decide to write it at that specific time?
- One can also suggest that Condorcet, who was already living half-clandestinely, meant to leave behind a legacy, with the intention of promoting a subject of enquiry which, as he wrote a few months later, "despite the successful attempts of some mathematicians, remains, as it were, in its early stages and ...
- He did not conceive a completely original system, but he did create a synthesis of all the theories of his predecessors.
- Two days later he was found dead in his prison cell and it is not known if he died from natural causes or whether he was murdered or took his own life.
- His uncompromising directness of manner and inability to suffer illogical windbags in silence made him many enemies and few friends.
- His weak voice, lack of oratorical powers, and tendency to bore the Convention by the excessive height of his arguments was one of the tragedies of the Revolution.

Born 17 September 1743, Ribemont, France. Died 29 March 1794, Bourg-la-Reine (near Paris), France.

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Analysis, Astronomy, Geography, Geometry, Physics, Statistics

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