Lange (2000) famously argues that although Jeffrey Conditionalization is non-commutative over evidence, it’s not defective in virtue of this feature. Since reversing the order of the evidence in a sequence of updates that don’t commute does not reverse the order of the experiences that underwrite these revisions, the conditions required to generate commutativity failure at the level of experience will fail to hold in cases where we get commutativity failure at the level of evidence. If our interest in commutativity is, fundamentally, an interest in the order-invariance of information, an updating sequence that does not violate such a principle at the more fundamental level of experiential information should not be deemed defective. This paper claims that Lange’s argument fails as a general defense of the Jeffrey framework. Lange’s argument entails that the inputs to the Jeffrey framework differ from those of classical Bayesian Conditionalization in a way that makes them defective. Therefore, either the Jeffrey framework is defective in virtue of not commuting its inputs, or else it is defective in virtue of commuting the wrong kinds of ones.

中文翻译：

---

交换性、规范性和整体论：再访朗格

Lange (2000) 著名地认为，尽管 Jeffrey 条件化在证据上是不可交换的，但由于这一特征，它并没有缺陷。由于在不交换的更新序列中颠倒证据的顺序不会颠倒支持这些修订的经验的顺序，因此在经验水平上产生交换失败所需的条件将不成立在证据级别上获得交换失败。如果我们对交换性的兴趣从根本上说是对信息的顺序不变性的兴趣，那么在更基本的经验信息水平上不违反这一原则的更新序列不应被视为有缺陷。本文声称，作为对 Jeffrey 框架的一般辩护，Lange 的论点失败了。Lange 的论点意味着 Jeffrey 框架的输入与经典贝叶斯条件化的输入不同，这使得它们有缺陷。因此，要么 Jeffrey 框架由于不交换输入而存在缺陷，要么由于交换错误类型的输入而存在缺陷。