In The Gaia Hypothesis, philosopher Michael Ruse, with his characteristic clarity and wit, uses Gaia and its history, its supporters and detractors, to illuminate the nature of science itself. Gaia emerged in the 1960s, a decade when authority was questioned and status and dignity stood for nothing, but its story is much older. Ruse traces Gaia’s connection to Plato and a long history of goal-directed and holistic—or organicist—thinking and explains why Lovelock and Margulis’s peers rejected it as pseudoscience. But Ruse also shows why the project was a success. He argues that Lovelock and Margulis should be commended for giving philosophy a firm scientific basis and for provoking important scientific discussion about the world as a whole, its homeostasis or–in this age of global environmental uncertainty—its lack thereof.