The Gaia hypothesis (GH) emerged in the mid-1960s through James Lovelock, a chemist who later found support in the biologist Lynn Margulis. In the 1970s, Lovelock, in collaboration with Margulis, claimed that life and the Earth form a single, self-regulative homeostatic system, essentially presenting the notion of the Earth being alive or that it behaves in ways like a living organism. The term “Gaia”, which Lovelock derived from his friend and novelist William Golding, was the name given to this idea, which Lovelock would soon directly link to religion,
“Science has left a moral vacuum behind… Gaia is important because it gave us something to which we were accountable… Because of that ethical significance, Gaia starts to become more than just science. It begins to veer into that area previously occupied by religion” (1).
Although the GH proved quite popular within the general public, no doubt partly because it emerged during the heydays of the New Age movement, scientists have dismissed the hypothesis in no uncertain terms (2).
The Earth is Alive
Lovelocks’s GH presents ideas ranging from the relatively uncontroversial to what strikes many as absurd. On the uncontroversial side there is the claim the Earth’s biosphere is a somewhat homeostatic system. On the side of absurdity, as it will likely be perceived by most readers, is that the Earth is literally a living organism with a tendency to take care of itself. Human beings, explains Lovelock, are the “central nervous system” of the Earth (3), yet he also maintains humans are its “pollution” (4). This view presents a dualism: on the one hand humans are healers and restorers of ecology essential to the Earth’s survival, yet on the other they are a threat to the Earth’s functioning and health. To Lovelock, persons are conflicting opposites: they are essentially the doctor and the disease.
In response to criticisms of his idea, Lovelock postulated a model he called ‘Daisyworld’ to demonstrate the Earth as a self-regulating mechanism able to regulate its own temperature in a non-mysterious way (5). He claimed that a self-regulating mechanism could emerge automatically from life interacting with its environment and therefore one need not appeal to teleology. This was in part Lovelock’s attempt to show the GH is consistent with evolution, which would offset much of the criticism of his theory coming from the scientific camp. His supporter Margulis, however, was far more critical of evolution, claiming natural selection to be incapable of explaining the emergence of higher levels of biological organization.
Most readers will likely find it difficult to perceive the Earth as a living organism. One issue is that Lovelock and Margulis define life in an unconventional way in order to ascribe the notion of life to the Earth. In biology, for example, a necessary condition for something to rightly be deemed a living organism is its involvement within evolutionary processes (6). All living organisms belong to evolving populations, have ancestors, and interact in complex ways with other living organisms. But of course none of this seems to be the case with the Earth. Earth has no ancestor, belongs to no biological population, does not produce offspring, and participates in no evolutionary processes. It is difficult in light of this to view the Earth as being a living entity. Philosopher Massimo Pigliucci explains it this way,
“Take, for instance, the basic Gaian idea that Earth is an “organism.” Although biologists do recognize a large variety of objects to which the label may be applied—from the straightforward example of individual vertebrates such as ourselves to the so-called “super-organisms” that are the colonies of eusocial insects—it is hard to see in what sense a planet may be considered a legitimate instantiation of the concept. Organisms, without exceptions, come in populations, and these populations evolve by natural selection and other means, pretty much well characterized (though not necessarily exhaustively so: Pigliucci and Müller 2010) by standard population and quantitive genetic theory (Hartl and Clark 2006; Falconer and Mackay 1996, respectively). Earth is not a member of a population of planets, it doesn’t produce variable offspring that inherits some of its characteristics and then competes for limited resources with other such offspring, and it most certainly doesn’t evolve in anything like the biological sense of the term, it just changes over time (and so do other planets, stars, galaxies and the universe itself—without anyone having proposed that they are “organisms” of a sort)” (7).
There are further topics one might wonder about. For example, consciousness, which seems a basic property of life. The difference between a living human being and a stone is the fact that the former has conscious experience of the world, namely the ability to think about things out there in the world (outside of oneself) and about things internal to oneself (such as mood, sensation, etc.), whereas the stone does not. But if consciousness is an essential property of life, then one must wonder if the Earth qualifies in the absence of evidence that it itself is conscious.
Scientific and Public Reception
The idea of a breathing, living Earth is attractive to many people. As Michael Ruse, who has studied the GH in detail, explains, “[T]alk about Earth as an organism—living, breathing, weeping, sweating, farting (don’t laugh, it’s coming up), and possibly dying—grabs the imagination” (8). It is an especially popular idea in certain religious circles, such as in the New Age and various Neo-Paganisms such as Wicca, Goddess theology, Druidry, and so on. Devotees of these traditions often view nature and the environment to be infused with Spirit, which motivates ecological sensitivity and protection. Many Pagans are pantheists as they view God and the world as inseparably connected. Such views appear to be, in some sense, hylozoic, which is the view that all matter, including the Earth, has life and therefore value. That persons like Lovelock and Margulis have presented such ideas exist will no doubt find a warm reception among Pagans.
Nonetheless, the GH is viewed far less favourably by mainstream scientists, especially evolutionary biologists. The evolutionary biologist John Maynard Smith called the GH “an evil religion” and the ecologist Robert May, who became president of the Royal Society, referred to Lovelock as “a holy fool.” Thus, voices like these and many others like them, with very few exceptions, from within the scientific establishment have rejected the GH since its inception on the grounds that it fails to be a scientific hypothesis at all. They also charge that its claims go against most of what scientists have discovered about biology and evolution. These attitudes from established scientists likely explain why Lovelock quickly stopped attempting to convince other scientists of his ideas via peer-reviewed publications and instead resorted to decades of public campaigning to spread the GH. As it turned out, Lovelock’s campaigns were quite successful. The term “Gaia”, for example, gained popular attention, a publishing house used the Gaia name (they also published Gaia: an Atlas of Planet Management), there is a “Gaia Song”, and many popular books devoted to the idea.
It seems, as Pigliucci argues, that the GH’s extensive rejection by scientists, yet popular embrace by the public, suggests “the general public is, unfortunately, prone to adopt all sorts of quasi- or even downright pseudo-scientific beliefs. On the other hand, bad ideas are rejected by the scientific community even when they are advanced by otherwise credentialed scientists” (9). But some researchers of this field, notably the philosopher Ruse, have, despite remaining skeptical, noted how the GH actually developed from a relatively straightforward idea that is both scientifically respectable and uncontroversial. The claim that the Earth’s biosphere is a somewhat homeostatic system is uncontroversial and simply highlights how it is, as a biophysical system, resistant to major changes, at the least within a certain range. But a biophysical system, the critic charges, is not a living organism. Ruse also reveals that the GH’s failure to attract favour from the scientific establishment is not merely a case of it being in conflict with established theory, but also because it traces back to the foundations of Western philosophy, in particular to the tradition of organicism in Plato’s thought. This tradition claims that the behaviour of entire systems is not explicable by the properties of their parts alone. Such a view is, however, inconsistent with modern science that has successfully embraced reductionism, namely the idea that complex systems can be reduced to, or are no more than, their constituent parts.
Tim Lenton, a professor of Earth system science at the University of Exeter, understands why evolutionary biologists have dismissed the GH; such biologists seem to be “interested only in what can be explained through evolution by natural selection. Having convinced themselves that Gaia cannot be a product of natural selection, they have long since dismissed it” (10). However, this is not necessarily the case for climatologists and geochemists, neither of whom are primarily concerned with natural selection, but who instead find that the GH has encouraged them to think about the Earth as a system and about how life is intimately involved in feedback mechanisms governing its behaviour. The GH at least has some value in this respect.
The GH’s image has not been helped by the controversial figures who have joined and/or support the movement. Names such as Rupert Sheldrake, author of A New Science of Life: The Hypothesis of Morphic Resonance (1982), and Fritjof Capra, the author of The Tao of Physics (2010), whom also teaches that “The earth, then, is a living system; it functions not just like an organism but actually seems to be an organism—Gaia, a living planetary being” (11), do not prove favourable to the movement’s perception among scientists. Little wonder then that Pigliucci equates it with the pseudo-scientific mumbo jumbo of a Deepak Chopra or Dr. Oz, writing that “Gaia is a vacuous, largely metaphorical, notion; it’s not based on any plausible scientific understanding of organic evolution; and it was pushed in increasingly dubious fashion both by its originators and by a cadre of questionable secondary characters” (12). Ruse, evidently just as much a critic although seemingly more kind in the use of his words, concludes that “in the opinion of many they [Lovelock and Margulis] failed the test” (13)
- Ruse, Michael. 2013. The Gaia Hypothesis: Science on a Pagan Planet. Chicago: University of Chicago Press.
- Dutreuil, Sebastien. 2013. “Michael Ruse, The Gaia hypothesis: science on a pagan planet.” History and Philosophy of the Life Sciences 36(1):149-151. p. 149.
- Lovelock, James. 1979. Gaia, a New Look at Life on Earth. Oxford University Press. p. 138-139.
- Lovelock, James. 1979. Ibid. p. 114.
- Ruse, Michael. 2013. Ibid. p. 156.
- Turner, Derek. 2013. Neo-Naturphilosophie: A Review of Michael Ruse’s Gaia: Science on a Pagan Planet. Chicago: University of Chicago Press. p. 479.
- Pigliucci, Massimo. 2014. “Why Gaia?” Ethics and the Environment 19(2):117-124.
- Ruse, Michael. 2013. Ibid. p. 35.
- Pigliucci, Massimo. 2014. Ibid. p. 122.
- Lenton, Tim. 2014. “Review: A Philosophical Look at Gaia.” BioScience 64(5):455-456.
- Capra, Fritjof. 2010. The Turning Point: Science, Society, and the Rising Culture. Fontana.
- Pigliucci, Massimo. 2014. Ibid. p. 121.
- Ruse, Michael. 2013. Ibid. p. 202.