 Even though the Principal Principle has important, extensive applications in Bayesian statistics as just explained, de Finetti (1970 [1974]) argues that it is actually dispensable and thus need not be accepted as a norm. To be more specific, he argues that the Principal Principle is dispensable in a way that changes little of the actual practice of Bayesian statistics. His argument relies on his exchangeability theorem. See Gillies (2000: 69–82) for a non-technical introduction to this topic; also see Joyce (2011: sec. 4.1) for a more advanced survey.