Note: This is an older version of this revised entry.
The Gaia hypothesis, proposed by UK scientist James Lovelock in the 1960s and now usually termed Earth System Science, suggests that Earth's Biosphere forms a self-regulating Homeostatic System analogous to a living organism (see Ecology); the name is taken from the Greek earth-goddess, also spelt Gaea or Ge, and was suggested to Lovelock by William Golding. The provenance of the concept lies deep in Western civilization, being first clearly articulated by Plato in his Timaeus (circa 360 BCE), though its clear association with pantheism (which Christianity treated as heresy during the centuries of its domination) may explain the infrequency of references to anything like Gaia before recent times. The pantheism of Baruch Spinoza (1632-1677), who was Jewish, is not really an exception. It was not until the nineteenth century that philosophers like Gustave Theodor Fechner (1801-1887) or William James (1842-1910) would consider the concept of a Living World or living universe with any seriousness.
Many sf Utopias include the general notion of a Gaia-like harmony – perhaps empathy (see ESP), perhaps true symbiosis (see Parasitism and Symbiosis) of all Earthly life: this is, for example, a repeated theme in the novels of Philip E High and extends across the Solar System – with the universe eventually to follow – in Eric Frank Russell's earlier "Design for Great-Day" (January 1953 Planet Stories; vt "The Ultimate Invader" in The Ultimate Invader and Other Science-Fiction, anth 1954 dos, ed Donald A Wollheim). What might be termed the strong Gaia hypothesis assumes an emergent planetary consciousness. Isaac Asimov invokes such a Gaia (thus named) as an ideal planetary state in Foundation's Edge (1982), with aspirations towards a galaxy-wide "Galaxia". David Brin's Earth (1990) culminates with the birth of a conscious and powerful Gaia via a somewhat implausible mechanism of Upload into the Earth itself. A more mystical Gaian world-consciousness, energized by Sex, features in Storm Constantine's Hermetech (1991). In Lovelock (1994) by Orson Scott Card and Kathryn H Kidd, "Gaiaology" is the science which harmonizes Terraforming with a colony world's existing Ecology (see Colonization of Other Worlds).
John Varley uses the name Gaea for the sentient Macrostructure of his Titan (1979) and its sequels. Piers Anthony's Science Fantasy Incarnations of Immortality sequence includes a personified Gaea or Nature as one of the supernatural civil servants known as Incarnations; she takes centre stage in Being a Green Mother (1987). Several authors have generalized the Gaia concept to encompass Living Worlds other than Earth: such a planetary consciousness is awakened by human interference with Ecology in Richard McKenna's "Hunter, Come Home" (March 1963 F&SF), precedes the arrival of humans on the colony world of Sheri S Tepper's True Game series – notably in Dervish Daughter (1986) and Jinian Star-Eye (1986) – and predicts the passing of Homo sapiens in Caitlín R Kiernan's "The Colliers' Venus (1893)" (in Naked City: Tales of Urban Fantasy, anth 2011, ed Ellen Datlow). A miniature example is the complex Alien cave-system of Piers Anthony's Chthon (1967), which has developed its own emergent intelligence. [DRL]
see also: Elisabeth Ayrton; Cynthia Joyce Clay; Tony Daniel; Maurice Dantec; Robert Froese; Gäa; Reginald Glossop; Richard Grant; Fred T Jane; Omega Point; Simearth.