A system’s wave function is uniquely determined by its underlying physical state

Weaddress the question of whether the quantum-mechanical wave function of a system is uniquely determined by any complete descriptionof the systems physical state.Weshow that this is the case if the latter satisfies a notion of free choice. This notion requires that certain experimental parameters-those that according to quantum theory can be chosen independently of other variables -retain this property in the presence of. An implication of this result is that, among all possible descriptionsof a systems state compatible with free choice, the wave function Y is as objective as.