Chapter 2 explores the theoretical framing of the book. It explains the basic concepts of biopolitics and governmentality and how (neo)liberalism and power are approached and understood in a Foucauldian framework. The chapter outlines the features of contemporary biopolitics as part of a neoliberal governmentality, as well as what a governmentality and biopolitical perspective entails for the study of sustainable development and resource governance; and how we can conceptualize both (neo)liberalism and the workings of power within a (green) governmentality framework. It does so by tracing the meaning of populations and scarcity in liberal economic thought. It 26also analyses the production of meaning around notions such as limits, scarcity, basic needs, and resilience in sustainable development discourse, and how these notions relate to different forms of life and their hierarchy. The framework developed in this chapter provides theoretical insights into how neoliberal techniques of governing use the agency of free subjects.