Marie-Jean-Antoine-Nicolas Caritat, Marquis de Condorcet
b. Ribemont, France 17 September 1743
d. Bourg-la-Reine, France 29 March 1794

Due to the publication of a mathematical memoir in 1765, Condorcet came to the attention of scientists of France. He was elected as a member of the Academy of Sciences in 1769 eventually becoming its permanent secretary. Later he became a member also of the Académie Française. Due to his political activities after the French Revolution, particularly the publication of the pamphlet Avis aux français (A Warning to the French), a warrent was issued for his arrest on 8 July 1793. After a period of flight, Condorcet was arrested on 27 March in Clamart and taken to the prison in Bourg-la-Reine. He was found dead the next morning. This prompted the rumor that he had committed suicide.

Condorcet is best known for the Essai sur l'application de l'analyse à la probabilité des décisions rendues à la pluralité des voix, 1785. (At Gallica.)

As for probability, there are the following:

• A memoir on the Theory of Probability consisting of six parts. This was published in the Hist. de l'Acad...Paris. Todhunter's assessment of these papers is that they are confused. We must agree.
  
  1. First Part: "Réflexions sur la règle générale qui prescrit de prendre pour valeur d'un évènement incertain, la probabilité de cet évènement, multiplée par la valeur de l'évènement en lui-même," Histoire de l'Académie Royale... Paris 1781. pp. 707 - 720. This was read to the Academy on August 4, 1784.  One should note that Condorcet also remarks on the Petersburg Problem in this part.
     
     
  2. Second Part: "Application de l'analyse à cette question: Déterminer la probabilité qu'un arrangement régulier est l'effet d'une intention de la produire," Histoire de l'Académie Royale... Paris 1781. pp. 720- 728. Parts 1 and 2.
     
     This is related to the following:
     
     Daniel Bernoulli's "Recherches physiques et astronomiques sur le problème proposé pour la second fois par l'Académie Royale des Sciences de Paris," Recueil des pieces qui ont remporté le prix de l'Académie Royale des Sciences, T. 3, 1734.
     
     Rev. John Michell's "An Inquiry into the probable Parallax, and Magnitude of the fixed Stars, from the Quantity of Light which they afford us, and the particular Circumstances of their Situation," Philosophical Transactions, Vol. LVII. Part I, 1767, pp. 234-264.
     
     
  3. Third Part: "Sur l'évaluation des Droits éventuels," Histoire de l'Académie Royale... Paris 1782. pp. 674-691. Part 3. Here Condorcet examines the evaluation of claims on property and of annuities.
     
     
  4. Fourth Part: "Réflexions sur la méthode de déterminer la Probabilité des évènemens futurs, d'après l'Observation des évènemens passés," Histoire de l'Académie Royale... Paris 1783 (1786). pp. 539-553.
     
     
  5. Fifth Part: "Sur la probabilité des faits extraordinaires," Histoire de l'Académie Royale... Paris 1783. pp. 553-559. Parts 4 and 5.
     
     
  6. Sixth Part: "Application des principes de l'article précédent à quelques questions de critique," Histoire de l'Académie Royale... Paris 1784. pp. 454-468. Part 6. This section concerns the testimony of witnesses.  Of some small interest may be the work of Isaac Newton, referenced by Condorcet, The Chronology of Ancient Kingdoms Amended published in 1728.

• The article Probabilités in the Encyclopédie mèthodique: Éléments du calcul des probabilités, art. 4.
  
  
• Élémens du calcul des probabilités, et son application aux jeux de hasard, a la loterie, et aux jugemens des hommes 1805. (At Gallica)
  
  This work is rather curious. It was published after the death of Condorcet. The author of the introduction presents the text as a fourth volume supplement to Euler's Lettres a une Princesse d'Allemagne. The sections of the work are follows:
  
  1. (I) On the interest of money pp. 2- 31.
  2. (II) On a method to form some tables pp. 31 - 56
  3. (III) On the fundamental principal of the calculus of probabilities pp. 56 - 79
  4. (IV) On the nature of truths to which the calculus of probabilities is able to lead pp. 79 - 100
  5. (V) On the manner to compare among them some events of different probabilities, and to find a mean value which can represent the different values among them of unequally probable events (Included here is a discussion of the Petersburg paradox) pp. 100 - 120
  6. (VI) Application of the calculus of probabilities to questions where the probability is determined (Included here is a discussion of the Lottery of France) pp. 121 - 145
  7. (VI) On the manner to establish some terms of comparison among the different risks in which one can be delivered with prudence, in the hope to obtain some advantages of a given value (Tables of mortality) pp. 145 - 150
  8. (VII) On the application of probabilities to games of chance pp. 150 - 170
  9. General Tables of the Sciences which have for object the application of the calculus to the political and social sciences. pp. 171 - 210

Section 9 seems to have been reprinted from the Journal d'instruction social (22 June, 6 July 1795; Oeuvres I. 539-573). Here are Sections 5- 8. 

Encyclopedia Mèthodique

Three related articles by Condorcet were included in the Encyclopedia Mèthodique. These are Absent, Probabilité and Substitutions. See also d'Alembert and Diderot. 

Population Estimates

Condorcet, du Séjour and Laplace jointly engaged in an estimation of the population of France. The result of their work appeared in a series of six reports published in the Mémoires de l'Académie Royale des Sciences of Paris in the years 1786 (pp. 703-718), 1787 (pp. 577-593), 1788 (pp. 703-717),  1789 (pp. 601-610) and   (pp. 755-767).