This book examines the question of what we mean when we talk about life, revealing new insights into what life is, what it does, and why it matters. Jenell Johnson studies arguments on behalf of life—not just of the human or animal variety, but all life. She considers, for example, the Standing Rock Sioux tribe’s fight for water, deep ecologists’ Earth First! activism, the Voluntary Human Extinction Movement, and astrophysicists’ positions on Martian microbes. What she reveals is that this advocacy—vital advocacy—expands our view of what counts as life and shows us what it would mean for the moral standing of human life to be extended to life itself. Including short interviews with celebrated ecological writer Dorion Sagan, former NASA Planetary Protection Officer Catharine Conley, and leading figure in Indigenous and environmental studies Kyle Whyte, Every Living Thing provides a capacious view of life in the natural world. This book is a must-read for anyone interested in biodiversity, bioethics, and the environment.