Ecology: A Human Responsibility proposes a fundamental reconsideration of ecological science and humanity’s place within the cosmos. Moving beyond the traditional separation between humanity and nature, it develops a relational, systemic, and historical conception of ecology grounded in the exchanges through which beings and systems exist and evolve. Drawing on history, philosophy, anthropology, and contemporary ecological research, the book introduces a new conceptual framework centered on ontological initiative, ecological viability, and the cosmos–human dialogue. It examines how humanity’s unprecedented planetary power transforms the conditions of ecological responsibility and calls for new ethical principles and political institutions. Combining theoretical innovation with historical analysis, this work opens new perspectives for understanding and addressing the ecological challenges of the Global Age.