 Both of these aspects can be seen in the reception of Everett’s ideas by Bohr and his circle. While Everett saw his own theory as directly opposed to von Neumann’s approach, he believed that he could provide a justification for Bohr’s idea of complementarity. Bohr, however, rejected the attempt to apply the notion of quantum state to a description of the whole universe. (The rejection of Everett’s ideas in Copenhagen in fact rather tragically contributed to Everett leaving physics in favour of military operations  research.[36])  