By Bruno Latour and Timoth M. Lenton
A Common-Sense View That Is Not So Common
The public discourse about the state of the planet is currently in a paradoxical situation: on the one hand, everyone involved in the politics of climate accepts the idea that Earth behaves as a regulated system that has been dangerously pushed by human action out of its normal conditions of operation; on the other hand, the hypothesis that Earth is indeed a self-regulating system remains highly controversial—and most people do not connect the idea of Earth regulation with Lovelock’s and Margulis’s “discovery” of Gaia. Thus, the common horizon of political action and moral commitment—Earth is a system put out of whack that should be brought back inside some form of order through the regulation of human activity—remains a local and disputed intellectual and scientific idea.
The reason for this paradox is that the Gaia theory has either been embraced with too much enthusiasm or rejected with too much scepticism, without unpacking its exact content. No wonder, as order and regulation are terms that pertain jointly to science and to politics. Those for whom it is obvious that there is some order in the regulation of the Earth as well as those for whom it remains a vague metaphor, might not have zoomed in on the precise ways through which Gaia was introduced. No matter if they come from philosophy or from science, they seem to have pigeonholed the argument to suit their preconceptions of how nature is supposed to rule, rather than be sensitive to the originality of the phenomena offered for inquiry. The result is that after half a century from its inception, it is still hard to find a widely shared definition of Gaia.
There are of course good reasons for that. The first is that any new phenomenon is defined by comparison with some already familiar situation. Gaia however is a unique phenomenon—at least as long as we have no proof of another planet modified by life to provide some sort of baseline. So, it’s no wonder that metaphors don’t help much in defining Gaia: if you are happy with one version, it is sure to be wrong. You cannot zoom in on its specificity by just considering nature as a whole. Hence the many misunderstandings accumulated over the years around the idea that the Earth is alive, that it is an organism, a superorganism, a machine, a cybernetic feedback control device, a spaceship, a body politic, and so on. Even the tamed notion of system is no more than a fragile simile in spite of the now common expression Earth System Science (ESS)—the polite euphemism sometimes used to avoid naming Gaia too directly. Whilst there is a fairly widely held perception that ESS has replaced the idea of Gaia, we argue it is important to differentiate them. Specifically, Gaia originated and expanded in space and time from within a preexisting Earth system. Strangely, defining such a phenomenon requires a sort of negative geology reminiscent of the apophatic ways that theologians had recourse to when trying to probe God’s uniqueness.
The second reason for the difficulty of making sense of Gaia is that it’s not clear if it's a discovery of a new phenomenon or the introduction in science, as well as in philosophy, of a new way to look at all phenomena on Earth. As Sébastien Dutreuil has shown in a meticulous inquiry of its historical development, Gaia is simultaneously a hypothesis, a testable theory, a summary of highly specific facts, a worldview, and a philosophy of nature all mixed together. Not to mention the claim made by some of its proponents that it might be a new religion or a new spirituality. This uncertainty explains the wide range of reactions triggered by any utterance of the word Gaia.
It is the aim of the present paper not to choose too fast what Gaia consists of because we claim that Lovelock’s and Margulis’s discovery might be just as unique as the object it tried to describe. In other words, Gaia might be the name of a shift in understanding of how to approach many phenomena of what was lumped together before in the notion of nature. This is why we are both—one coming from social science and the other from natural science— joining forces to keep open the possibility that we are dealing here with a change in what could be called a world view, by which we mean a distribution of traits affecting science, as well as politics, morality, and the arts. In brief, a cultural paradigm shift comparable in scope to the one introduced at the time of the scientific revolution by Galileo Galilei.