On the meaning of wave function

Questions on the meaning of wave function are still very puzzling in the spite of remarkable success of quantum predictions. Any answer substantially depends on how quantum theory emerges from an underlying pre-quantum theory (if there is any). Recently, it has been shown that interpreting the wave function as representation of knowledge about some underlying reality, contradicts quantum theory. Here we show that this reasoning is valid only for a specific class of pre-quantum theories, usually called as hidden-variables. We elaborate a different possible class where quantum theory is deduced “just as thermodynamics is deducible from statistical mechanics”. We show that aforementioned reasoning is not valid any more for this new class of pre-quantum theories. In fact,here the wave function represents only knowledge about an underlying reality.