 The Principle of Conditionalization has been challenged with several putative counterexamples. This section will examine some of the most influential ones. We will see that, to save that principle, some Bayesians have tried to refine it into one or another version. A number of versions have been systematically compared in papers such as those of Meacham (2015, 2016), Pettigrew (2020b), and Rescorla (2021), while the emphasis below will be centered on the proposed counterexamples.