Is Value Under Hypothesis Value?

In the context of two recent yet distinct philosophical debates—over choice under conditions of moral uncertainty and over transformative choices—several philosophers have implicitly adopted a thesis about how to evaluate alternatives of uncertain value. The thesis says that the value a rational agent ought to attach to an alternative under the hypothesis that the value of this alternative is x, ought to be x. I argue that while in some contexts this thesis trivially holds, in the context of the two debates in which the thesis has been adopted, it does not. I also discuss several implications of this failure.