Understanding the emergence of classical physics from the quantum world does not require a unique quasiclassical framework; there are undoubtedly a large number of different possibilities, any one of which could for the circumstances of interest provide “classical” results within a suitable approximation (further comments on nonuniqueness will be found in subsection 11.3 below). In constructing a quasiclassical description decoherence plays a useful role in the sense that it removes the effects of quantum interference which might otherwise render a quasiclassical family inconsistent, preventing the application of the Born rule and its generalizations. Once again, this statement can be supported by model calculations of an appropriate sort which make it plausible, but work still remains to be done in coming to a full understanding of decoherence in quantum terms. Invoking decoherence by itself outside the framework provided by the histories approach does not solve the conceptual difficulties of quantum theory; see, e.g., Adler (2003).