Alive

A major work of interdisciplinary nonfiction that redefines how we understand life, agency, and intelligence

What does it mean to be alive? The slow contortion of a plant toward light, the dive of hawks toward their prey—these are purposeful actions. But where does that purpose come from, and what does it tell us about who we are?

In Alive, natural philosopher Melanie Challenger draws on biology, philosophy, physics, ecology, and the history of science to reveal a radical truth: to be alive is first and foremost a way of being in a body. From Greenland sharks that can live for half a millennium, to birds that sense the Earth’s magnetic field through their retinas, and even slime molds that solve mazes, this book tells a new story of intelligence in the living world.

A scientifically grounded challenge to the idea that life is either a machine run by genes or an essence separable from the body, Alive restores agency, purpose and meaning to organisms in an age of artificial intelligence and biodiversity loss. By recognizing that our bodies are both how and why we are alive, this book asks what it would mean to live—and to act—with that knowledge.