In this paper a general hydrodynamic mode coupling theory of equilibrium fluctuations in simple liquids is developed from molecular considerations. The approach developed here avoids the shortcomings of previous mode coupling theories by adopting a complete hierarchy of equations for the slow modes of a hydrodynamic system and solving it formally through the N ordering approximation scheme developed previously by Machta and Oppenheim. A series is obtained from the hierarchy of equations which allows the generalized transport coefficients to be obtained exactly in the thermodynamic limit up to arbitrary order in the wavevector, frequency and mode coupling parameters. A self-consistent equation for the transport coefficients is formulated up to Burnett order in the wavevector and all orders in the mode coupling parameter. The results are similar to phenomenological models used by previous researchers.
