The traditional approach to theorizing planning has consisted of a confused mixture of normative theory, on the one hand, and attempts to develop a positivistic grounding to the subject, on the other. This is most obviously present in work such as that of Davidoff and Reiner (1973) who painstak­ ingly analyse the distinction between facts and values, showing that the former are descriptive truth statements, while the latter possess the wholly separate status of moral statements or assertions of preference. On this basis they derive the planning process as an exercise involving three levels of activity led off by value formulation, followed by identification of means whereby valued ends may be achieved, and the implementation (or as they call it ‘effectuation’) of policy.