 Much of the contemporary physics community’s interest in Bohr’s correspondence principle (variously understood) is in prima facie violations of this principle by particular classes of physical systems. For example, Joseph Ford and Giorgio Mantica, in their article, “Does Quantum Mechanics Obey the Correspondence Principle? Is It Complete?” define the correspondence principle as requiring that “any two valid physical theories which have an overlap in their domains of validity must, to relevant accuracy, yield the same predictions for physical observations” (Ford and Mantica 1992, p. 1087). Their concern is whether quantum mechanics can account for the behavior of chaotic classical systems. Similarly, Wojciech Zurek defines the correspondence principle as a demand for an agreement between the “quantum and classical expectation values” (Habib et al. 1998), arguing that without the phenomenon of decoherence, the correspondence principle is violated.