The challenging, inspiring, irreducible pluralism of Gaia

John Ziman: 1 April 2004

One of the disconcerting things about Gaia is that scientists find it so very disconcerting. Is this because it can't be squeezed into any of their established pigeonholes. It mixes together concepts from the physical, biological and physical sciences. Why is it so difficult to combine these into a coherent, unified representation or vision?

I argue that this intrinsic pluralism is one of its glories and fascinations. Think historically. The planet Earth assembled, imbricated and remodelled itself by purely physico-chemical processes. For a billion years or so, everything that happened could be described in the language of gravitational forces, thermodynamic phases, chemical compounds, etc.

Then, life emerged. Novel entities, with unprecedented properties - i.e. distinct organisms - appeared on the scene. To describe their phenomenology required a whole new conceptual vocabulary. Thus, the further history of Gaia had to be written, in part, in the language of biology. This had to include a great many absolutely basic terms such as organism, function, behaviour, metabolism, perception, predator, survival, epigenesis, descendant, evolution, etc. for which there were no equivalents in the language of the physical sciences.

In due course, a million or so years ago, another conceptual fulguration occurred. The emergence of consciousness enabled hominids to engage in another completely unprecedented phenomenology. This, again, is strongly influencing the career of Gaia. So yet another new language is required, with terms for social concepts such as symbol, communication, idea, institution, plan, story, contract, money, leader, love, death, kin, ancestor, god, action, etc. These, in turn, have no strictly biological counterparts - although, of course, they are also subject to the necessities of their physical and biological dimensions.

So now we have to make sense of a world containing entities of these three different kinds, each governed by a different 'logic' and defined in a different conceptual language. These differences have arisen naturally, are universally recognised in natural languages, and have given rise to different bodies of scientific knowledge. And because the successive events of their emergence were entirely unpredictable, as was what emerged at each stage, these phenomenologies, logics, languages and sciences are irreducibly distinct, and cannot be unified into a single formal system. The pluralism of the sciences is not just a weakness of the human intellect: it is a product of the physico-bio-psychic history of our Gaian abode.

Many of the most interesting - and deeply puzzling - topics in modern science relate to the 'boundary objects' that straddle these domains, such as genes, arefacts, information, mind/brains, etc. Of all these, Gaia is the most intriguing, not only as the birth mother of all three domains, but as a natural entity centred on a 'triple point' where they all meet. Thus, questions such as 'Is Gaia alive?', 'Did Gaia evolve?' or 'Can Gaia be saved?' are so constrained terminologically that they cannot be answered meaningfully. Nevertheless they challenge our capacity to make interpretative connections across the frontiers of incommensurability between the plurality of domains of scientific knowledge.