Abstract

The state of a classical system represents physical reality by assigning truth values, true or false, to every proposition about the values of the system’s physical quantities. I present an analysis of the Frauchiger-Renner thought experiment (Frauchiger D, Renner R: Single-world interpretations of quantum mechanics cannot be self-consistent. arXiv eprint quant-ph/1604.07422, 2016), an extended version of the ‘Wigner’s friend’ thought experiment (Wigner E: Remarks on the mind-body question. In: Good IJ (ed) The scientist speculates. Heinemann, London, 1961), to argue that the state of a quantum system should be understood as purely probabilistic and not representational.