 Other philosophers have provided arguments against strict (and Jeffrey) conditionalization: van Fraassen (1989) holds that rationality does not require the adoption of a particular update rule (but see Hájek, 1998 and Kvanvig, 1994). Arntzenius (2003) uses, among others, the “shifting” nature of self-locating beliefs to argue against strict conditionalization, as well as against van Fraassen’s reflection principle (see van Fraassen 1995; for an illuminating discussion of the reflection principle and Dutch Book arguments see Briggs 2009a). The second feature used by Arntzenius (2003), called “spreading”, is not special to self-locating beliefs. Weisberg (2009) argues that Jeffrey conditionalization cannot handle a phenomenon he terms perceptual undermining. See Huber (2014) for a defense of Jeffrey conditionalization.