1. Introduction: Spatial planning at the intersection among complexity, institutions, and justice.- 2. What is planning theory and why is it important?.- 3. Two orthodox ideas of planning: Planning as teleocratic intervention and planning as a rational decision method.- 4. The role of planning and the role of planners: Political dimensions, ethical principles, communicative interaction.- 5. Distinguishing "planning" from the "plan"? On rule-making and infrastructure provision.- 6. The just city: Institutional and spatial justice, social and distributive justice, concepts and conceptions of justice.- 7. On property: Basic rights and contingent titles.- 8. Conclusions. Enduring and emerging challenges in planning 9. Annex I. Rethinking public and private property: Are the "commons" an alternative path?.- 10. Annex II. Informality and the dynamics of unauthorised settlement.