Quantum Knowledge, Quantum Belief, Quantum Reality: Notes of a QBist Fellow Traveler

Understand

I consider the "Quantum Bayesian" view of quantum theory as expounded in a 2006 paper of Caves, Fuchs, and Schack.

• I argue that one can accept a generally personalist, decision-theoretic view of probability, including probability as manifested in quantum physics, while nevertheless accepting that in some situations, including some in quantum physics, probabilities may in a useful sense be thought of as objectively correct.
• This includes situations in which the ascription of a quantum state should be thought of as objectively correct.
• I argue that this does not cause any prima facie objectionable sort of action at a distance, though it may involve adopting the attitude that certain dispositional properties of things are not "localized" at those things.