Alfred Marshall provides a still widely cited definition in his textbook Principles of Economics (1890) that extends analysis beyond wealth and from the societal to the microeconomic level, creating a certain synthesis of the views of those still more sympathetic with the classical political economy (with social wealth focus) and those early adopters of the views expressed in the Marginal Revolution (with individual needs focus). Marshall's inclusion of the expression wellbeing was also very significant to the discussion on the nature of economics: