 Here, one’s future self is taken as an expert to which one ought to defer. The Reflection Principle admits of a Dutch Book argument (van Fraassen 1984). There is another way to defend the Reflection Principle: this synchronic norm is argued to follow from the synchronic norm that one ought, at any time, to be fully certain that one will follow the diachronic Principle of Conditionalization (as suggested by Weisberg’s 2007 modification of van Fraassen’s 1995 argument).