Condorcet Marquis de, title of Marie-Jean- Antoine-Nicolas de Caritat (1743–94), French philosopher and political theorist who contributed to the Encyclopedia and pioneered the mathematical analysis of social institutions. Although prominent in the Revolutionary government, he was denounced for his political views and died in prison.
Condorcet discovered the voting paradox, which shows that majoritarian voting can produce cyclical group preferences. Suppose, for instance, that voters A, B, and C rank proposals x, y, and z as follows: A: xyz, B: yzx, and C: zxy. Then in majoritarian voting x beats y and y beats z, but z in turn beats x. So the resulting group preferences are cyclical. The discovery of this problem helped initiate social choice theory, which evaluates voting systems. Condorcet argued that any satisfactory voting system must guarantee selection of a proposal that beats all rivals in majoritarian competition. Such a proposal is called a Condorcet winner. His jury theorem says that if voters register their opinions about some matter, such as whether a defendant is guilty, and the probabilities that individual voters are right are greater than ½, equal, and independent, then the majority vote is more likely to be correct than any individual’s or minority’s vote. Condorcet’s main works are Essai sur l’application de l’analyse à la probabilité des décisions rendues à la pluralité des voix (Essay on the Application of Analysis to the Probability of Decisions Reached by a Majority of Votes, 1785); and a posthumous treatise on social issues, Esquisse d’un tableau historique des progrès de l’esprit humain (Sketch for a Historical Picture of the Progress of the Human Mind, 1795). See also PROBABILITY, SOCIAL CHOICE THE- ORY, VOTING PARADO. P.We.