 This norm implies that one should have a credence in a logical truth (indeed, a credence of 1) and that, when one has credences in some propositions, one should also have credences in their conjunctions, disjunctions, and negations. So Probabilism in its standard version asks one to have credences in certain propositions. But that seems to be in tension with the fact that Probabilism is often understood as a coherence norm. To see why, note that coherence is a matter of fitting things together nicely. So coherence is supposed to put a constraint on the combinations of attitudes that one may have, without saying that one must have an attitude toward such and such propositions—contrary to the above version of Probabilism. If so, the right version of Probabilism must be weak enough to allow the absence of some credences, also called credence gaps.