Modern environmentalism owes a great debt to philosopher, professor, and writer Arne Naess, cofounder of the Deep Ecology movement. Here, editors Alan Drengson and Bill Devall provide a comprehensive yet accessible volume of Naess's most groundbreaking and seminal essays, which have remained influential among environmentalists to this day. Drawing from influences as diverse as Eastern religious practices, Gandhian nonviolent direct action, and Spinozan unity systems, Naess's writing calls for cooperative action to protect the earth on which we dwell, encouraging individuals and communities to develop their own distinctive “ecosophies.” These writings, full of Naess's characteristic enthusiasm, wit, and spiritual fascination with nature, provide a look into the remarkable philosophical underpinnings of his own social and ecological activism, as well as an inspiration for all those looking to follow in his footsteps. This is an essential anthology from one of modern environmentalism's most important and relevant voices.