 Now, suppose that a person with this credence distribution receives E as new evidence. It seems that as a result, there should be some change in credences. But how should they change? According to the second norm, called the Principle of Conditionalization, the possibility incompatible with E (i.e., the rightmost possibility) should have its credence dropped down to 0, and to satisfy Probabilism, the remaining credences should be scaled up—rescaled to sum to 1. So this person’s credence in hypothesis H has to rise in a way such as that depicted in  figure 2.  