What is nature? What is humanity’s place in nature? And what is the relationship of society to the natural world? In an era of ecological breakdown, answering these questions has become of momentous importance for our everyday lives and for the future that we and other life-forms face. In the essays of ‘The Philosophy of Social Ecology’, Murray Bookchin confronts these questions head on: invoking the ideas of mutualism, self-organization, and unity in diversity, in the service of ever expanding freedom. Refreshingly polemical and deeply philosophical, they take issue with technocratic and mechanistic ways of understanding and relating to, and within, nature. More importantly, they develop a solid, historically and politically based ethical foundation for social ecology, the field that Bookchin himself created and that offers us hope in the midst of our climate catastrophe. Murray Bookchin (1929–2006) was an active voice in ecology, anarchist, and communalist movements for more than fifty years. His groundbreaking essay, “Ecology and Revolutionary Thought” (1964), was one of the first to assert that capitalism’s grow-or-die ethos was on a dangerous collision course with the natural world that would include the devastation of the planet by global warming. Bookchin is the author of The Ecology of Freedom, among two dozen other books.