# Philosophy Dictionary of Arguments

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Decision theory: is not about decidability of problems within finite time, but about the consequences of decisions. See also rationality, actions, consequentialism, consequence, practical inference, decidability, counterfactual conditionals.

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Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments.

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Nicolas de Condorcet on Decision Theory - Dictionary of Arguments

Sunstein I 25
Decision Theory/Collective Intelligence/Condorcet/Sunstein: the accuracy of the judgments to which statistically selected groups arrive is best explained by Condorcet's theorem. (1)
Definition Jury Theorem/Condorcet/Sunstein: in the case of a yes/no question with a 50% chance for each of the two outputs, the probability of a correct answer tends towards 100% if the size of the asked group increases.
Sunstein: Groups here are better than individuals and larger groups better than small ones, as long as two conditions are met: 1. the majority rule is applied, 2. each person is probably more likely to be right than wrong.
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I 26
The phenomenal success of websites such as the Zagat Survey (which deals with restaurant ratings etc.) is due to Condorcet's Jury Theorem. (2)
Democracy/Sunstein: even for justifications of democracy the theorem is used. (3)
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I 27
Conditions/Condorcet:
1. It should not matter to the participants whether their votes would be decisive.
2. The parties involved should not be influenced by the votes of the others.
3. The likelihood that a participant is right should be statistically independent of the likelihood that another participant is right. (4)
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I 28
Sunstein: it turned out that the Jury Theorem also applies if the 3rd condition is violated. (5)
Problems/Sunstein: if the probability of group members being wrong increases, the probability of a wrong overall result increases, too.
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I 29
There are examples of groups in which misconceptions prevail: For example, 93% of Americans believe that Arab terrorists destroyed the World Trade Center, but only 11% of Kuwaitis believe this. In order for Condorcet's theorem to be applied, we must assume a certain level of information from the participants.
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I 42
Errors: in many areas of knowledge, groups of participants do not have purely accidental errors, but there is a certain system of misconceptions.

1. See William P. Bottom et al., “Propagation of Individual Bias through Group Judgment: Error in the Treatment of Asymmetrically Informative Signals,” Journal of Risk and Uncertainty 25 (2002): 152–54.
3. See Goodin, Reflective Democracy, 91–108.
4. Siehe . Bottom et al., “Propagation of Individual Bias through Group Judgment, p. 153
5. ibid.

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Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments
The note [Author1]Vs[Author2] or [Author]Vs[term] is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.

Condo I
N. de Condorcet
Tableau historique des progrès de l’ esprit humain Paris 2004

Sunstein I
Cass R. Sunstein
Infotopia: How Many Minds Produce Knowledge Oxford 2008

Sunstein II
Cass R. Sunstein
#Republic: Divided Democracy in the Age of Social Media Princeton 2017

> Counter arguments against Condorcet

Ed. Martin Schulz, access date 2021-08-03