This paper calls for a re-appraisal of McGee’s analysis of the semantics, logic and probabilities of indicative conditionals presented in his 1989 paper Conditional probabilities and compounds of conditionals. The probabilistic measures introduced by McGee are given a new axiomatisation—built on the principle that the antecedent of a conditional is probabilistically independent of the conditional—and a more transparent method of constructing such measures is provided. McGee’s Dutch book argument is restructured to more clearly reveal that it introduces a novel contribution to the epistemology of semantic indeterminacy, and shows that its more controversial implications are unavoidable if we want to maintain the Ramsey Test along with the standard laws of probability. Importantly, it is shown that the counterexamples that have been levelled at McGee’s analysis—generating a rather wide consensus that it yields ‘unintuitive’ or ‘wrong’ probabilities for compounds —fail to strike at their intended target; for to honour the intuitions of the counterexamples one must either give up the Ramsey Test or the standard laws of probability. It will be argued that we need to give up neither if we take the counterexamples as further evidence that the indicative conditional sometimes allows for a non-epistemic ‘causal’ interpretation alongside its usual epistemic interpretation.

本文要求重新评估 McGee 在他 1989 年的论文条件概率和条件的复合中提出的指示性条件的语义、逻辑和概率的分析. McGee 引入的概率度量被赋予了新的公理化——建立在条件的前件在概率上独立于条件的原则之上——并提供了一种更透明的构建此类度量的方法。McGee 的荷兰书论证进行了重组，以更清楚地表明它为语义不确定性的认识论引入了新的贡献，并表明如果我们想要保持 Ramsey 检验以及标准概率定律，则其更具争议性的含义是不可避免的。重要的是，它表明，麦基分析中的反例——产生了相当广泛的共识，即它产生了化合物的“不直观”或“错误”概率——未能达到预期的目标；为了尊重反例的直觉，必须要么放弃拉姆齐检验，要么放弃标准概率定律。有人认为，如果我们将反例作为进一步的证据表明指示性条件有时允许在其通常的认知解释之外进行非认知“因果”解释，那么我们都不需要放弃。