 A number of important formal results, known as “representation theorems”, show that this claim about describability can be derived from a set of prima facie plausible general principles, aka “postulates” or “axioms”, pertaining to the agents’ preferences over acts. Furthermore, not only are these axioms collectively sufficient to derive SEU’s claim, but a significant proper subset of them also turn out to be individually necessary. Unsurprisingly then, much of the work on assessing the empirical adequacy of SEU has focused on the testing of the aforementioned axioms. Such tests could, in the best case, undermine a key reason to endorse the claim and, in the worst, provide grounds to reject it. Accordingly, a brief sketch of Savage’s own early result is in order.