 Bohr shared with von Neumann and with Heisenberg the idea that that quantum mechanics is in principle applicable to any physical system (as shown e.g. by his willingness in the course of his debates with Einstein to apply the uncertainty relations to parts of the experimental apparatus when not used as an apparatus), while denying that it is meaningful to apply it to the entire universe. What is central to Bohr’s views, however, is not so much the movability of the cut within a given experimental arrangement, but the fact that different experimental arrangements will generally select complementary aspects of the description of a physical system, corresponding to different equally necessary classical pictures that however cannot be combined. In this sense, for Bohr classical concepts are conceptually prior to quantum mechanics. In a terminology reminiscent of Kant, the quantum state is not an anschaulich (‘intuitive’) representation of a quantum object, but only a symbolic representation, a shorthand for the quantum phenomena that are constituted by applying the various complementary classical pictures. (See also the entry on the  Copenhagen interpretation.)