On the selection of preferred consistent sets

The theme of this paper is the multiplicity of the consistent sets appearing in the consistent histories approach to quantum mechanics. We propose one criterion for choosing preferred families among them: that the physically realizable quasiclassical domain ought to be one corresponding to classical histories. We examine the way classical mechanics arises as a particular window and the important role played by the canonical group and the Hamiltonian. We finally discuss possible implications of our having a selection criterion generally and of our criterion in particular.