"In the consistent-histories approach, the classical limit can be studies by using appropriate subspaces of the quantum as a "coarse graining," analogous to dividing up into nonoverlapping cells in classical statistical mechanics. This coarse graining can then be used to construct quantum histories. It is necessary to show that the resulting family of histories is consistent, so that the probabilities assigned by make good quantum mechanical sense. Finally, one needs to show that the resulting quantum dynamics is well approximated by appropriate classical equations."