Concluding Remarks

Abstract

Bohr’s principle of complementarity and the ensuing Copenhagen interpretation brought both the creation of quantum mechanics and, for the time being, the Bohr-Pauli dialogue to an end. The long sought for new system of operationally defined concepts upon which quantum mechanics was to have been built upwards had remained elusive, and in this sense Bohr’s views had finally prevailed. But the inadequacy of the existing concepts, and in particular of visualisable models, had now been established and given a foundation. As Pauli had always maintained this foundation lay in their operational inadequacy, expressed in terms of a complementarity between definition and observation which effectively prohibited any operationally based definition. In philosophical terms the compromise was somewhat unfortunate. By stopping short of any assertions as to the nature and location of any reality underlying the defined limits of knowledge the Copenhagen interpretation masked the very real differences of philosophical viewpoint between its main creators and proponents, and in fact ran generally counter to their views. For all their insistence on the role of observation, both Pauli and Heisenberg were for example, and were to remain, philosophical realists. Scientifically, however, this limitation of the Copenhagen interpretation provided it with a great strength, wedding it closely to the theory and rendering it effectively immune to changes of philosophical opinion. Only when identified with an antirealist philosophy has it ever come under serious attack, and such an identification is, as our analysis has shown, a misleading one.