Non-Locality Versus Locality:. the Epistemological Background of the Einstein Bohr Debate

In its core, the non-locality-locality debate is a discussion about the concept of the physical reality. The difference between the measurement bases of classical and quantum mechanics is often interpreted as a loss of reality arising in quantum mechanics. In this paper it is shown that this apparent loss occurs only if one believes that everyday experience determines the Euclidean space, instead of considering this space, both in classical and quantum mechanics, as a theoretical construction needed for measurement and representing one part of a dualistic space conception. From this point of view, Einstein's program of a unified field theory can be interpreted as the attempt to find a physical theory that is less dualistic. However, if one regards this dualism as resulting from the requirements of measurements, one can hope for a weakening of the dualism but not expect to remove it completely. Further, it follows from the requirements of measurements that the Heisenberg cut cannot be arbitrarily far moved towards the observer.

Epistemological discussions on quantum mechanics yield two insights: (i) To acquire physical knowledge, means of cognition are always necessary, and measurement provides this means. (ii) The space of measurement and the space of the representation of physical dynamics must be distinguished conceptually; both coincide factually in classical physics, but not so in quantum mechanics.