This article discusses the problem of the effectiveness of spatial planning by means of a comparison between the theory of Saey (spatial planning regulates a social struggle for collective interests) and collaborative planning as elaborated by Healey, starting from the viewpoint that spatial planning is a large-scale practical project. This type of project has a built-in tendency to fail. Saey and Healey present a similar way out, considering that the purpose of spatial planning should be the attainment of democratic quality in society. However, they diverge with respect to the societal field of action that they envisage. The societal field of action in Healey’s approach seems to imply a formal theory of praxis. A theory on governance threatens to replace a theory of society. This raises doubts about the effectiveness of collaborative planning. As (spatial) planning is a style of governance in the general sense (management of collective affairs), and collaborative planning is a textbook example of networked governance (as opposed to hierarchical government), this conclusion may be generalized to other forms of governance.