This book argues that degrowth is more than a reminder that GDP is not welfare. It offers a deeper diagnosis: capitalist economies are structurally and politically dependent on growth, yet destabilized by the very pressures and consequences that this dependence generates. At the heart of this contradiction lies relentless capital accumulation - the driving force of capitalism, a core component of modernity's cosmology, and a root cause of multiple crises. Against this background, degrowth calls for reorganizing societies around different priorities: well-being for all within planetary boundaries. Such a project requires confronting underdevelopment alongside overdevelopment, opposing extreme poverty alongside extreme wealth, and organizing needed growth alongside needed degrowth. It also demands challenging growthism - the powerful ideology of progress that continues to shape development thinking across North and South, to the point that even anti-capitalist movements often remain captive to its logic. But what does degrowth mean for the majority world? This book takes up that question without implying that critiques of growth and visions of alternatives began in Europe. In fact, it would be plainly misguided to assume that people in the global South have been waiting for European theorists to 'discover' the contradictions of growthism and to articulate alternatives. Intellectual and political traditions from the global South - under different labels - have long advanced ideas that resonate with, and in some cases anticipated by decades, core degrowth principles. The book's scope is to connect these threads in a coherent framework and to clarify what degrowth contributes to contemporary development debates.