Condorcet's Terrifying Assumption

Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode! A French aristocrat proved that majorities converge on the truth. The proof needs one condition, and he spent his life building the very things that destroy it. In this episode The jury theorem built from scratch, on three people, with no equations Why 101 jurors reach 98 per cent while a referendum reaches nothing at all What thirty per cent correlation does to a crowd of a hundred The theorem running in reverse — below fifty per cent competence, large groups become reliably wrong Krishna Ladha's repair: correlation as a budget rather than a veto Franz Dietrich's objection, which is that the premises are never justified at the same time Why the theorem's best case looks like Galton's queue in Plymouth and nothing like an election Sources The paper Condorcet, marquis de (1785). Essai sur l'application de l'analyse à la probabilité des décisions rendues à la pluralité des voix. Paris: Imprimerie Royale. https://archive.org/stream/bub_gb_RzAVAAAAQAAJ/bub_gb_RzAVAAAAQAAJ_djvu.txt The modern reading, and the objections Paulson, L. (2023). A brief history of collective intelligence, democracy, and governance. In Boucher, Hallin & Paulson (eds.), The Routledge Handbook of Collective Intelligence for Democracy and Governance. Routledge. Ladha, K. K. (1992). The Condorcet jury theorem, free speech, and correlated votes. American Journal of Political Science 36(3), 617–634. Dietrich, F. (2008). The premises of Condorcet's jury theorem are not simultaneously justified. Episteme. https://www.cambridge.org/core/journals/episteme/article/abs/premises-of-condorcets-jury-theorem-are-not-simultaneously-justified/066FBBE781B9E25B2F8A2D3075121C6D Condorcet himself Condorcet (1781, as 'Joachim Schwartz'). Réflexions sur l'esclavage des nègres. https://classiques.uqam.ca/classiques/condorcet/reflexions_esclavage_negres/reflexions_esclavage_negres.html Condorcet (1790). Sur l'admission des femmes au droit de cité. https://blog.univ-angers.fr/dictionnairefeministes/2017/01/30/condorcet-jean-antoine-nicolas-caritat-marquis-de/ Encyclopaedia Britannica, Marquis de Condorcet. https://www.britannica.com/biography/Marie-Jean-Antoine-Nicolas-de-Caritat-marquis-de-Condorcet Credits Written and presented by Niccolò Pescetelli. A PSi production. Sources for every episode are in the show notes.