 QBism (originally short for ‘quantum Bayesianism’) is a view of quantum mechanics developed by Chris Fuchs and co-workers, which has made current the idea that subjective probabilities à la de Finetti can be used also in quantum mechanics (see the entry on  quantum Bayesian and pragmatist views of quantum theory).  The position is more radical than this, however, in that it does not only claim that the quantum probabilities as defined by the quantum state should be interpreted subjectively, but that the quantum state itself is merely an expression of an agent’s degrees of  belief.[39]