Abstract
The author gives explicit quasi-particle Hamiltonians, including interactions, for several magnetic impurity models and shows that the application of mean field theory to these gives asymptotically exact results as T to 0 and H to 0 corresponding to Fermi liquid theory. This approach provides a conceptual link between the intuitive phenomenological theory of Landau and Nozieres, and the microscopic theory of Luttinger and Yamada.