Abstract: Human societies become more complex over time. Today’s networked globalization offers unprecedented depth of bureaucracy, rules, procedures, and degrees of specialization. Societies commonly respond to challenges by creating additional layers of complexity—new diversity, greater connectedness. Nevertheless, anthropologist Joseph Tainter argues in his book “The Collapse of Complex Societies” (1988) that the soaring costs of supplying the constant inflow of energy that is required for maintaining social complexity can put societies at risk of sudden collapse. Facing an economic and ecological crisis, we revisit Tainter’s argument, unpack its elements, define key concepts, and place it in a broader debate on the relationships between energy, social complexity, democracy, and societal collapse. We ask: What does Tainter and other literature on complexity and collapse contribute to the debate on economic degrowth and reorganization? As such, our analysis addresses the need to face the current crisis and discusses demand for societal transformation.