An objection first raised by Dowker &amp; Kent (1996), and subsequently repeated by  Kent (1998), Schlosshauer (2004), and Wallace (2008), among others, is that quasiclassical frameworks are by no means the only possible consistent families of histories in a closed quantum system.  In particular, one can have consistent families in which there is quasiclassical behavior up to some time followed by something which is not at all quasiclassical at a later time.  This would be a serious objection if historians were claiming that there must be a unique family of histories which can be used to describe the world, but such is not the case.  The physicist is at Liberty to choose a family whose histories closely resemble those of classical mechanics, and the existence of alternative frameworks in no way diminishes the validity of such a quasiclassical description, for reasons indicated in section 4.2 of Griffiths (2013). One senses that underlying such criticisms is the expectation that any good physical theory must satisfy the principle of unicity, to which we now turn.