It is shown that two simple principles N and P concerning probabilities of conditionals can be combined with the standard ratio analysis of conditional probability only at the expense of complete triviality: no measure that satisfies all three can assign any proposition a non-trivial probability (probability greater than 0 and less than 1). The proof of this is trivial. Moreover, N and P are shown to follow from the Ramsey Test, Import-Export, Reflexivity and a weak principle of suppositional consistency (entailed by the ratio analysis), as well as from considerably weaker plausible properties. Together the results constitute a triviality result with a very strong conclusion from very weak premises, with a trivial proof. It sharpens the question: which principle is to blame?