A Thomistic Analysis of the Gaia Hypothesis: How New is This New Look at Life on Earth?

A THOMISTIC ANALYSIS OF THE GAIA HYPOTHESIS: HOW NEW IS THIS NEW LOOK AT LIFE ON EARTH? LAURA LANDEN, 0.P. Providence College Providence, Rhode Island W:HAT IS THE Gaia hypothesis? A recent article in Time magazine mentions the first major scientific conerence on Gaia, sponsored by the American Geophysical Union in 1988.1 The scientists ended their meeting by giving James Lovelock an exuberant standing ovation. Lovelock 's book Gaia: A New Look at Life on Earth, first published in 1979, is now in its second edition.2 James E. Lovelock, British atmospheric chemist, introduced the Gaia hypothesis in 1975. This hypothesis emerged from his comparison of the chemical composition of Earth's atmosphere with the atmospheres of Venus and Mars. He found the contrast striking: Earth's atmosphere, hospitable to life, is markedly unlike the atmospheres of her two closest neighbors, Venus and Mars, both considered lifeless. Unsatisfied with mere chance as an explanation of this difference, Lovelock attributed a kind of active influence on the atmosphere by the whole of living organisms (called the biosphere) to effect conditions favorable for life. The following is taken from Lovelock's initial article on Gaia in 1975 : 1 Eugene Linden, "How the Earth Maintains Life," Time, November 13, 1989, p. 114. 2 See James E. Lovelock, Gaia: A New Look at Life on Earth (New York: Oxford University Press, 1987). Lovelock has published more recent work on Gaia. See James E. Lovelock, The Ages of Gaia: A Biography of Our Living Earth (New York: Bantam Books, 1990). 1 2 LAURA LANDEN, O.P. It appeared to us that the Earth's biosphere is able to control at least the temperature of the Earth's surface and the composition of the atmosphere. Prima facie, the atmosphere looked like a contrivance put together co-operatively by the totality of living systems to carry out certain necessary control functions. This led to the formulation of the proposition that living matter, the air, the oceans, the land surface were parts of a giant system which was able to control temperature , the composition of the air and sea, the pH of the soil and so on as to be optimum for survival of the biosphere. The system seemed to exhibit the behaviour of a single organism, even a living creature. One having such formidable powers deserved a name to match it; William Golding, the novelist, suggested Gaia-the name given by the ancient Greeks to their Earth goddess.• In this paper I present some of the factual evidence for the Gaia hypothesis and identify the underlying concepts of this position. Next, I note some reasons the hypothesis has encountered objections within the scientific community. Finally, I look to Aristotle and to Thomas Aquinas, as commentator, for insight as to how these apparent contrasts might find resolution. The factual evidence for Lovelock's claim lies in known measurements about the atmospheres of Venus, Earth, and Mars. In addition, he was able to construct a mathematical model of an abiological Earth. The following comparisons are of interest : GASES. PLANETS Lifeless Actual Venus Earth Mars Earth Carbon Dioxide 96.5% 98% 95% 0.03% Nitrogen 3.5% 1.9% 2.7% 79% Oxygen trace 0.0% 0.13% 21% Surface Temp °C 459 240to -53 13 340 aJames E. Lovelock and Sidney Epton, "The Quest for Gaia," New Scientist 65 (1975) : 304. 'Table taken from Lovelock, Ages, p. 9. GAIA HYPOTHESIS: A THOMIST ANALYSIS 3 Carbon dioxide, one of the " greenhouse " gases, is related to surface temperature. Nitrogen and oxygen, both highly reactive gases, are essential to life as we know it. When he first proposed the Gaia hypothesis, Lovelock himself may not have been aware of the ancient roots of the concept of earth, even the universe, as a living organism. J. Donald Hughes has traced this ancient view among the Greeks and Romans, noting the following progression : First, the Earth is the oldest goddess, supporter and nurturer of her children, human and non-human, and therefore entitled to respect and worship.... Second, the Earth is a living being of whom humans are only part. Right relationship with the Earth means that the total organism is...