 Since the mid-1950’s, the term “Copenhagen interpretation” has been commonly used for whatever it is that the person employing the term takes to be the ‘orthodox’ viewpoint regarding the philosophical issues raised by quantum mechanics. According to Howard (2004), the phrase was first used by Heisenberg (1955, 1958), and is intended to suggest a commonality of views among Bohr and his associates, included Born and Heisenberg himself. Recent historiography has emphasized diversity of viewpoints among the figures associated with the Copenhagen interpretation; see the entry on  Copenhagen interpretation of quantum mechanics,  and references therein. Readers should be aware that the term is not univocal, and that different authors might mean different things when speaking of the“Copenhagen interpretation.”