The functional formalism of classical statistical dynamics

A simple and general derivation of the functional formalism of classical statistical dynamics of Martin, Siggia and Rose (see Phys. Rev., vol.A8, p.423 (1973)) is presented without the necessity of introducing non-commuting operators into the discussion. This is achieved by making use of functional integral representations of the correlation and response functions of the system. Some approximation procedures based on the functional integral representation are briefly discussed.