Historian Paul Sabin recounts the 1980 bet between economist Julian Simon and biologist Paul Ehrlich over whether resource scarcity would drive up commodity prices. Ehrlich, author of 'The Population Bomb,' predicted that population growth would deplete resources, driving prices higher. Simon, an economic optimist, argued that human ingenuity would find substitutes and efficiencies, keeping prices stable or declining. They wagered on the price of five metals over a decade; Simon won decisively. Sabin uses this wager as a lens to examine the deeper conflict between environmental pessimists and market optimists that has shaped debates from the 1960s to the present. He traces how Ehrlich's apocalyptic predictions and Simon's cornucopian faith each captured partial truths while missing important complexities. The bet's aftermath - with each side claiming vindication while talking past the other - illustrates the difficulty of learning from evidence when worldviews are at stake. Sabin, a professor of environmental history at Yale, provides context for both positions while noting their limitations. For readers seeking to understand why environmental debates remain so polarized, this book provides historical perspective on intellectual traditions that continue to shape contemporary arguments about climate, population, and economic growth.