The dissertation addresses the negative consequences of the generally positive democratic ambition behind social planning: the good purpose may conceal less good actions. The aim is to study the thought-style of social planning and its most powerful topos, the denial of discrepancies. The focus of the dissertation is to exemplify how the denial of discrepancies and the consequences of denial become manifest. With emphasis on continuity and history, is shown how a Cartesian legacy shapes the thought-style of social planning, which is animated and upheld by the planning-collective: the integration of policy and science in planning. The planning-collective’s voice has become hegemonic through maintaining a harmony of illusions. The result is a lack of responsiveness to people’s varied modes of expression; voices that differ from the hegemonic thought-style are thus perceived as dissonance. Discrepancies in the form of differences of opinion and lack of consensus thus appear as sources of anxiety.  The mode of planning is based on a set of habitual thoughts and actions, topoi, that have become taken-for-granted. The result is an objectification of that which we call living, and the study shows through a number of examples, including “social economy”, how this form of objectification occurs. The epistemological frame of reference of the dissertation is constituted by Ludwik Fleck’s theory of thought-collectives, thought-styles and migrations of thought, and José Luis Ramírez’s action-theory, focused on language as action. Michel Foucault’s works on disciplining, political technologies, and discursive struggles are applied to create understanding of how the planning approach to representing people’s life activities has been shaped and how it influences them.