The paper explores the historical origins and theoretical foundations of the three-pillar conception of sustainability, which typically represents social, economic, and environmental factors. The authors review relevant historical literature to identify the genesis of this concept, noting that it emerged gradually from various critiques of the economic status quo from both social and ecological perspectives, as well as the United Nations' quest to reconcile economic growth with social and ecological problems. The popular three-circles diagram, first presented by Barbier in 1987, is discussed, along with the conceptualization of three pillars, which predates it. The paper highlights the lack of a theoretically rigorous description of the three pillars, attributing this to the diverse schools of thought that have contributed to the sustainability discourse. The authors also examine the institutionalization of sustainable development through documents like the Brundtland Report and Agenda 21, and the subsequent criticism of these documents for transforming a radical movement into a platform for legitimizing neoliberal policies. The paper concludes by discussing the competing realities and interpretations of the three pillars, including systems approaches and perspectives, and the central role of the economic pillar in the UN's sustainable development narrative.The paper explores the historical origins and theoretical foundations of the three-pillar conception of sustainability, which typically represents social, economic, and environmental factors. The authors review relevant historical literature to identify the genesis of this concept, noting that it emerged gradually from various critiques of the economic status quo from both social and ecological perspectives, as well as the United Nations' quest to reconcile economic growth with social and ecological problems. The popular three-circles diagram, first presented by Barbier in 1987, is discussed, along with the conceptualization of three pillars, which predates it. The paper highlights the lack of a theoretically rigorous description of the three pillars, attributing this to the diverse schools of thought that have contributed to the sustainability discourse. The authors also examine the institutionalization of sustainable development through documents like the Brundtland Report and Agenda 21, and the subsequent criticism of these documents for transforming a radical movement into a platform for legitimizing neoliberal policies. The paper concludes by discussing the competing realities and interpretations of the three pillars, including systems approaches and perspectives, and the central role of the economic pillar in the UN's sustainable development narrative.