Dmitri Gallow has recently proposed an ingenious accuracy-first vindication that our credence should be updated in accordance with conditionalization. This paper extends his idea to cases where we undergo only a partial learning experience. In particular, I attempt to vindicate, in the spirit of accuracy-first epistemology, that when we undergo what is called ‘Jeffrey partial learning’ in this paper, our credences should be updated in accordance with Jeffrey conditionalization, or at the very least, the update should be rigid. In doing so, I propose what I call the ‘Jeffrey-accuracy function.’ This function is not strictly proper and, at first glance, seems to rationalize ill-motivated credence updating. However, this turns out not to be the case.

Certain hypotheses cannot be directly confirmed for theoretical, practical, or moral reasons. For some of these hypotheses, however, there might be a workaround: confirmation based on analogical reasoning. In this paper we take up Dardashti, Hartmann, Thébault, and Winsberg’s (2019) idea of analyzing confirmation based on analogical inference Bayesian style. We identify three types of confirmation by analogy and show that Dardashti et al.’s approach can cover two of them. We then highlight possible problems with their model as a general approach to analogical inference and argue that these problems can be avoided by supplementing Bayesian update with Jeffrey conditionalization.

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.