La Terra è un organismo? Gaia come espediente persuasivo e come generatore di ipotesi scientifiche

In this essay, the history of the “Gaia hypothesis” is used as an example for dilemmas in science communication. James Lovelock invented and developed the idea of Gaia, while Lynn Margulis defended it and worked out a “metatheory” according to which scientific data are exaggerated into the image of the Earth as an organism. Heated reactions to Gaia produced different metatheories, arguing that Gaia was a product of ethical and unscientific choices, superimposed on scientific data. The essay defends the metatheoretical definition of Gaia as a “scientific narrative”, a hypotheses-generator which is part of science but works in an inspirational way. The accessibility of a scientific narrative is, at once, the source of its generative power, the hook to involve lay people in science, and the worrying factor for movements of scientists defending science against pseudoscience and other threats