判断聚合理论述评——关于社会选择理论的一种新进展

A Commentary on Theory of judgment aggregation:On a New Development of Theory of Social Choice

判断聚合理论的核心问题是如何摆脱"不可能性"困境,而"不可能性"困境的标志是包括投票悖论在内的衍申困境。衍申困境直接破坏了基于多数投票规则的集体选择的逻辑合理性,从而向多数投票规则的民主性提出了挑战。为了挽救集体选择的逻辑合理性,判断聚合理论不得不对多数投票规则加以限制甚至摒弃,同时力求避免向独裁规则退化。换言之,该理论在保留判断聚合的逻辑合理性的前提下,尽可能少地丧失聚合规则的民主性。然而,这一努力的结果却是难以令人满意的。

The core problem of theory of judgment aggregation is how to avoid the dilemma of impossibility, and the mark of the impossibility is the discursive dilemma which includes the voting paradox. The discursive dilemma destroys directly the logical rationality of collective choice that is based on the majority voting rule, therefore it makes a challenge to the democracy of majority voting rule. For saving the logical rationality of collective choice, theory of judgment aggregation has to place some restrictions on, even abandon, the majority voting rule, meanwhile tries to avoid degenerating towards the dictatorship rule ;or other, the theory tries to reduce the loss of democracy of aggregation rules as far as possible, presupposes that the logical rationality of collective choice can be retained. However, the result of this effort is not satisfactory.