Pollution, deforestation, elimination of species, greenhouse gases, depletion of the ozone layer. These results of human activity are, as most people would agree, undesirable. But why? What is the value of the natural environment that would be lost if this environment were destroyed or seriously degraded? This is the central question of environmental ethics and the focus of this book. This book argues that to properly understand how and why nature can have value requires a radical revisionof the way philosophy is understood and practiced.