Download A Philosophical Look at Gaia

Books
A Philosophical Look at Gaia
The Gaia Hypothesis: Science
on a Pagan Planet. Michael Ruse.
University of Chicago Press, 2013. 272
pp., illus. $26.00 (ISBN 9780226731704
cloth).
A
generation ago, the Gaia hypothesis was simultaneously met with
both an explosion of public popularity and an implosion of rejection
by many in the scientific community.
This rare occurrence is explained by
Michael Ruse, professor of philosophy
at Florida State University, in his entertaining and highly readable book The
Gaia Hypothesis: Science on a Pagan
Planet. The action centers on the 1970s
and 1980s, but Ruse traces the underlying reasons for this schism back to
Plato and two traditions of thought
that began with the ancient Greeks.
His aim is to show how our thinking
today is deeply influenced by the past.
Gaia was the brainchild of James
Lovelock; the idea was born in the
mid-1960s out of the observation that
Earth possesses a thermodynamically
remarkable atmosphere that is also
surprisingly stable in both its composition and its climate. Developed
in the early 1970s in collaboration
with the late Lynn Margulis, the Gaia
hypothesis postulated that life and its
planetary environment on Earth form
a single system that self-­
regulates
in a habitable state. To many, the
Gaia hypothesis represents a modern
scientific incarnation of a very old
idea that the Earth is, in some sense,
alive—or at least that it behaves, in
some ways, as an organism. Perhaps
unsurprisingly, the main scientific
objections to Gaia came from evolutionary biologists, who feel a strong
sense of ownership over the concept of what defines an organism.
How, they asked, could the Earth self-­
regulate like an organism when it
is not the product of evolution by
natural selection among a population
of reproducing planets?
http://bioscience.oxfordjournals.org
Ruse’s aim in The Gaia Hypothesis
is to show that the heart of this disagreement was not a simple case of
a new hypothesis’s appearing to be at
odds with established theory. Instead,
it stretches back to the foundations of
Western philosophy. The Gaia hypothesis, he explains, belongs to a long tradition of organicism, the philosophical
position that the behavior of whole
systems cannot be explained by the
properties of their parts alone. By contrast, modern science has largely been
a triumph of the tradition of reductionism (i.e., the idea that complex systems
are no more than the sum of their
parts), along with mechanism (i.e., natural wholes are essentially complicated
machines).
Ruse expertly traces these two
philosophical traditions from Plato
through the scientific revolution to
the time that Gaia hit the intellectual scene. He argues that the sturdy
plant of organicist science has always
been growing under the shadow of
reductionism and that Gaia is simply a
recent flowering of this. But the flowering of the Gaia hypothesis occurred
at a particularly bad time, when evolutionary biologists were in the middle
of trying to ensure that their theory
did not imply that natural selection
could act for the good of a group or of
a species, let alone for the good of life
as a whole.
The arrival of Gaia in the popular
consciousness, however, fell on fertile
ground. The embrace of Gaia by sectors of the public was, according to
the author, part of a long history of
hylozoism—the position that all matter,
including the Earth, has life and value
in its own right. This is the “pagan
planet” of Ruse’s subtitle, although
he is careful to point out that the
Gaia hypothesis does not go this far,
except in the hands of some of its New
Age devotees. He is curious enough,
however, to have visited Oberon ZellRavenheart, cofounder of the Church
of All Worlds and a writer and speaker
on the subject of neopaganism, to find
out more.
This is typical of Ruse’s chatty and
engaging style of writing. He treats
his central characters with a healthy
mixture of playfulness and respect.
Perhaps Ruse’s boldest proposition
is that his two main protagonists,
Lovelock and Margulis, actually belong
to two different intellectual traditions.
Lovelock, he claims, is a mechanist
at heart, whereas Margulis was a true
organicist. Ruse suggests that this can
be seen in the way that each responded
to the early criticisms of Gaia from
evolutionary biologists: Lovelock
produced a model—Daisyworld—to
illustrate that a self-regulating mechanism could emerge automatically
from life interacting with its environment, without any appeal to teleology.
Daisyworld operates through a crude
form of natural selection. Indeed,
Lovelock has always been eager to
demonstrate that Gaia is consistent
with evolution by natural selection,
whether his critics believe him or not.
Margulis, however, loved nothing more
than to goad evolutionary biologists.
She argued that natural selection alone
is not enough to explain the emergence
of higher levels of biological organization. She believed that symbiogenesis
was a crucial creative force and that
Gaia was symbiosis as seen from space.
Computer models such as Daisyworld
left her unmoved.
May 2014 / Vol. 64 No. 5 • BioScience 455
Books
Ruse’s analysis has a ring of truth
about it, but it would be wrong to
infer that Lovelock is not an organicist. In my experience, Jim has a keen
ability to intuit the behavior of whole
systems, even if he cannot (at least
at first) explain how they work in
a mechanistic sense. This was true
of his most famous invention, the
electron capture detector, and is also
true of Daisyworld. He conceived
the model but only later wrote it in
mathematical form with the help of
Andrew Watson.
The value of Ruse’s book is in how
he captures the wider importance
of the debate triggered by the Gaia
hypothesis. Like all good philosophers,
he makes the reader think about how
we think. For example, when is it
permissible to think in terms of parts
having a purpose for the whole? We
are not ridiculed for asking, “What is
the purpose of the eye for the whole
animal?” So, why is asking the purpose
of nitrous oxide gas for the biosphere
a laughing matter?
If I missed something from this
work, it was a look at Gaia from a
more contemporary scientific perspective. Ruse is writing as a historian of
science, with the aim of understanding events that happened a generation
ago. Unfortunately, this can create the
erroneous impression that the Gaia
hypothesis is a historical footnote that
has led nowhere scientifically.
Many of the evolutionary biologists
that Ruse discusses 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. But climatologists and geochemists, for example, do not expect
natural selection to explain how the
planet functions. The Gaia hypothesis triggered them to think about
the Earth as a system and about how
life is intimately involved in feedback
mechanisms that govern its behavior.
As a result, a whole field of Earth system science has emerged.
Even the reductionist triumphs of
molecular biology have led in some
456 BioScience • May 2014 / Vol. 64 No. 5
distinctly holistic directions. The
genomics revolution is continually
broadening our perspective on the
mechanisms of life and of evolution,
and those in the field of systems biology are attempting to understand
the emergent properties of biological systems. Even one of Gaia’s most
insightful critics, W. Ford Doolittle, has
argued that natural selection can happen through survival alone and, therefore, that Gaia and evolutionary theory
could be reconciled (Doolittle 2013).
Now that the controversy that arose
over the Gaia hypothesis is understood, we need to take a fresh look at
it from a twenty-first century perspective of flourishing systems science.
Has Gaia lost her relevance? I don’t
think so.
Reference cited
Doolittle WF. 2013. Natural selection through
survival alone, and the possibility of Gaia.
Biology and Philosophy. (27 February 2014;
http://link.springer.com/article/10.1007/
s10539-013-9384-0) doi:10.1007/s10539-0139384-0
TIM LENTON
Tim Lenton ([email protected])
is a professor of Earth system science
at the University of Exeter, in the
United Kingdom. He is the coauthor
with Andrew Watson of Revolutions
that Made the Earth
(Oxford University Press).
doi:10.1093/biosci/biu041
THE PROMISE AND PROBLEMS
OF RELIGIOUS ECOLOGIES
Ecology and Religion. John Grim
and Mary Evelyn Tucker. Island
Press, 2014. 280 pp., illus. $35.00
(ISBN 9781597267083 paper).
J
ohn Grim and Mary Evelyn
Tucker are two of the most wellknown ­
figures advocating religious
ecologies—the bridging of scientific
­
and religious worldviews. In their book
Ecology and Religion, they argue that
the religious component is a “missing link” (p. 27), “an important lens
whereby humans can understand and
reenvision their roles as participants
in the dynamic process of life” (p. 63).
In the last decade, this husbandand-wife team has been pivotal in the
Yale-based Forum on Religion and
Ecology. Before that, they edited a multi­
volume series at Harvard, and most
recently, they produced an Emmy
Award–winning film called Journey
of the Universe. Here, they set out “to
retrieve, re-examine, and reconstruct
these human–Earth relations that
are present in all the world religions”
(p. 42). This requires a survey with
a mission, and they succeed at highlighting thinkers who have retrieved,
reevaluated, and reconstructed their
faiths in order to practice accentuating (with an added fondness from
the authors for mnemonic alliteration) “reverence, respect, reciprocity,
restraint, redistribution, responsibility,
[and] restoration.” Their goal is to bring
awareness to the possibility that “religions thus hold a promise of extending
once again care and compassion to the
planetary community of life” (p. 42).
In volumes of this genre, their virtue must mirror their vice—that of
being both sketchy and simultaneously
insightful. “Painted in broad brushstrokes” (p. 44), the book is cosmopolitan in the original Greek sense, as
in a citizen of the cosmos. Grim and
Tucker find that the term anthropocosmic is better than anthropocentric
(p. 43). The first chapter introduces
a tension that characterizes the book
through contrasting phrases linked
by similarly contrasting conjunctions
(e.g., on the other hand, however, yet
at the same time, although, nonetheless, for the most part, whereas). This
grammatical tension reflects a certain historical accuracy and, to their
credit, Grim and Tucker are honest
about it. Complex affairs resist simplification: “The response of religion
to environmental concern will be
immensely varied around the planet
because these traditions are far from
univocal” (p. 20). The narrative has
an “often paradoxical and problematic
http://bioscience.oxfordjournals.org