In section 18.1, Keynes succinctly recapitulates the aim of the general theory, namely to identify those aspects of the complex of economic factors which serve to determine the national income and the volume of employment.
unresolved He also sets the stage for an analysis of how the state qua monetary and fiscal authority may tactically control these key factors to such ends as the maximization of employment in conjunction with national income, but I might not be accurately comprehending this.