 Probabilism is often regarded as a coherence norm, which says how one’s opinions ought to fit together on pain of incoherence. So, if Probabilism matters, the reason seems to be that coherence matters. This raises a question that divides Bayesians: What does the coherence of credences require? A typical Bayesian thinks that coherence requires at least that one’s credences follow Probabilism. But there are actually different versions of Probabilism and Bayesians disagree about which one is correct. Bayesians also disagree about whether the coherence of credences requires more than Probabilism and, if so, to what extent. For example, does coherence require that one’s credence in a contingent proposition lie strictly between 0 and 1? Another issue is what coherence requires of conditional credences, i.e., the credences that one has on the supposition of the truth of one or another proposition. Those and other related questions have far-reaching impacts on applications of Bayesian epistemology. For more on the issue of what coherence requires, see  section 3.