 Although it is easy to generate plausible examples of partial beliefs, it is harder to say exactly what is meant by a degree of belief. An agent's degree of belief in \(P\) may reflect their level of confidence in the truth of \(P\), their willingness to assent to \(P\) in conversation, or perhaps how much evidence is required to convince them to abandon their belief in \(P.\) A venerable tradition, receiving classical expression in Ramsey (1926) and de Finetti (1937), holds that degrees of belief are most directly reflected in which bets regarding \(P\) an agent is willing to accept. At least since Pascal (ca. 1658/2004), mainstream philosophical opinion has held that degrees of belief are well-modeled by probabilities (see Hacking (1975) for a readable history). To this day, subjective, or ‘epistemic’, probability remains one of the dominant interpretations of the probability calculus. 