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Heaven and Earth: An Awkward History

Mary Midgley on our changing views of our own planet, and the story they tell about the changing nature of rationality.

People in our civilization have viewed their planet in a huge variety of ways. Sometimes they have worshipped it, thought of it as their mother, felt awe and gratitude towards it for the gifts it gave them. At other times, however, they have despised and feared it. They have seen it chiefly as the opposite of heaven – as a mean and degraded realm that is likely to entrap them and stop them fulfilling their true destiny. Thus, the Oxford Dictionary gives as the meaning of earthy – “Heavy, gross, material, coarse, dull, unrefined …… characteristic of earthly as opposed to heavenly existence…”

Until very lately, this more hostile view has been much the more prevalent of the two in our culture, not only in religious thinking but also in the sciences. I don’t think we have noticed this bias, but it has been effective in many parts of our thinking. For a long time it prevented us from seeing the Earth as an intelligible system at all. This obstruction is only now beginning to lift.

That fear and distrust of the Earth draws much of its force from the strong natural imagery that links the up-down dimension with difference of value. Earth is ‘lower’ than us, the sky is ‘higher’. The Earth is, of course, also darker, while the sky is the source of light. Light and the upward direction always tend to stand for greater nobility.

This sort of thinking may seem naive, but it is remarkably strong. It still has an influence today far beyond the sphere of traditional religion. For instance, propagandists for spacetravel commonly take it for granted that aspirations towards what is literally higher – to what takes us away from the Earth – are also spiritually ‘higher’ – that is, nobler than anything that we can find below.

Is this way of talking just fantasy, just the casual extension of a figure of speech, or is there more to it? If we want to grasp its meaning, we may do well to look back briefly at the history of the symbolism to see how we have got here.

In our culture, heaven, containing God, has of course long been placed literally in the sky. Pre-Copernican cosmology developed this idea in some detail. It set heaven, containing God and his angels, outside a set of transparent concentric spheres that carried the Sun, Moon, stars and planets. All these bodies were made of a special substance – aether – distinct from the four elements with which we are familiar below. They all moved, too, with a circular motion, which was thought to be the most perfect of all motions, by contrast to the crude motion in a straight line (upwards or downwards) which is found on Earth.

Plato explained in the Timaeus that our brains themselves are revolving systems modelled on these heavenly circles and our thoughts, as they go round, echo these cosmic motions. The Earth, by contrast, was merely the dead point at the centre of the system, the place to which things fall if they can’t go upwards. Its central position was not a sign of importance but just marked its low status, its distance from everything of high value. After all – as Dante showed – what lay at the centre of Earth itself was Hell.

The business of Christian souls was, then, always to move upwards, away from this planet towards their true home. They were only visitors here, on a planet which had been created mainly as a stage for their interactions with God and especially for the drama of their salvation. This meant that, when Copernicus displaced the Earth from its central position, the humiliation that is often said to have accompanied this move was not fully felt. Though there was certainly a sense of confusion and insecurity, the citizenship of human souls in heaven remained and their salvation was still central business for the cosmos. Moreover – what is really interesting – this sense of complacent independence from the Earth even managed to survive the Enlightenment’s discrediting of religion.

When secular Westerners stopped seeing themselves as Christian souls subject to judgment, they did not conclude that they were only rather gifted terrestrial animals. Instead, they managed to see themselves in Cartesian terms as pure intellects – observers, set above the rest of the physical world in order to understand and control it. Anyone who wants to see how this image works today should have a look at the Strong Anthropic Principle, which proposes that the entire universe is essentially a device whose sole purpose is to foster intellectual beings of this kind – that is, us, or at least the physicists among us. Not surprisingly, these anthropicists stage their cosmic drama largely in outer space, treating the Earth and its fauna as more or less obsolete and expendable.

Studying the heavens was (then) directly studying the divine, and was therefore a specially noble occupation. Today, people would probably not give that reason for prioritising astronomy. But the notion that this study has a special spiritual value is still often expressed, for instance by astrophysicists such as Steven Weinberg. It is interesting to ask; is there really any reason why we should regard (say) research on a topic like black holes as essentially more spiritual than research on something earthly, such as parasites or black beetles? I suspect that Darwin would not have thought so, and I don’t know of any scientific basis for saying that he would have been wrong.

What, however, did that preference mean in the early days of modern science?

It had another element besides the natural symbolism of height. The special appeal of astronomy to mathematicallyminded thinkers like Plato and Pythagoras surely centred on the clarity of its patterns. Greek reasoners could see at once how they might hope to apply their mathematical methods to the heavens. The problem of how to apply them to the more complicated things on the Earth looked much more obscure, and for a long time it remained so. That is why, until the Renaissance, earthly things usually continued to be treated as genuinely messy and incomprehensible, a surd, chaotic mass that could often only be dealt with by rule of thumb based on experience. Aristotle protested against this, but he was not widely followed.

Thus, when scientific efforts to understand the physical world began once more at the Renaissance, they again began with astronomy. Copernicus and Galileo dealt primarily in stars and planets, though of course the earthly consequences of their thought also concerned them. And what they chiefly looked for was again simplicity. The traditional pattern of circles supplemented by epicycles had turned out not to give simplicity, so they tried to find it by altering their startingpoint.

Science always oscillates between two magnets, two equally important ideals. On the one hand it tries to represent the hugely complex facts of the world. On the other, it aims at clarity, and for that it needs formal simplicity. When mathematicians are in charge, the second ideal always tends to predominate over the first. And, for a long time, mathematics provided the only model of intelligibility that physical scientists saw how to work with. Within mathematics, too, they looked for the simplest and most regular forms.

This is why the ideal of using circles exercised such great power. Thus, when Kepler and his colleagues were trying to calculate the orbits of the planets, they found it quite impossible for a long time to admit that these paths might possibly be elliptical. They spent many years trying to avoid this conclusion and only accepted it in the end with the greatest reluctance. Like Plato, they had assumed firmly that orbits must be circular, because that was self-evidently the perfect shape for them.

This same longing for perfect circles was also relevant to questions about the shape of the Earth. Here, our planet’s original mean position was compounded by involvement in the Fall of Man. Mediaeval and Renaissance writers speculating about the Earth commonly deplored its rough and disorderly state, its infestation by mountains and holes which stopped it from being the perfect sphere that God must surely have meant to create. They thought this imperfection must surely be due to corruption caused by human sin

As scientific speculation advanced, various ingenious theories were proposed to explain just how this had happened. In the 1680s Thomas Burnet insisted that its present shape could not possibly be the original one. As he said–

There appearing nothing of any order or regular design in its parts, it seems reasonable to believe that it was not the work of nature, according to her first intention, or according to the first model that was drawn in measure and proportion, by the line and by the plummet, but a secondary work and the best that could be made of broken materials

He called it ‘a hideous ruin’, ‘a broken and confused heap of bodies’, ‘a dirty little planet’. He therefore explained that its original smooth form must have been shattered by Noah’s Flood, which had let loose the waters under the Earth. These waters had originally formed a continuous layer beneath the surface. But when human sin became too flagrant, God made them break out and cover the globe. This shattered the Earth’s crust, which has remained in pieces to the present day.

Since that time, the only process that had been at work was the gradual erosion of the mountains by rain. The existing Earth was thus a decaying ruin, a constant reminder of the disastrous effect of human wickedness. Like degenerate descendants of an ancient house, we were camping out in the damaged kitchens of the ancestral castle, the rest of which had been destroyed by their vice and folly of our ancestors. Speculations like this may well strike us as naïve, and we may certainly be surprised that they were thought necessary. But the conviction that there was something wrong, that the planet really ought to be a perfect sphere, was not just a religious one. It struck scientists of that day as a demand of reason. And indeed, when God is seen as the guarantee of order, the distinction between religious and scientific thinking on such questions hardly arises.

I want to draw attention here to this inability of genuine enquirers to see any less simple shape than a circle as rational. It is surely the kind of difficulty that recurs whenever we need to change and expand the language of thought – whenever we come, (as they say) to a paradigm-shift. It is the kind of difficulty that we are facing today about Gaia. I think it is perhaps somewhat like the trouble that we often have in responding to an unfamiliar kind of music or architecture. At first the patterns presented seem meaningless, indeed, they don’t seem to be patterns at all. Then, rather mysteriously, given time and good-will, their order begins to make sense to us. Just so, geographers found the idea of an Earth that failed to be spherical not just blasphemous but irrational, an unintelligent. That objection arose as naturally in direct thoughts about nature as it did in religious thoughts of a divine creating mind. The ideal of intelligibility was the same in both contexts, and of course it centred on a simplification of mathematics itself. Classical geometry was essentially the study of regular shapes. Nobody had yet proposed fractal geometry as an alternative way of detecting order.

The effect was that the Earth’s moral and spiritual reputation could not improve until it could somehow be seen as being more intelligible – that is, until somebody found a more suitable way of trying to understand it. Finding one was the achievement of James Hutton (1726-97) often called the father of geology. Hutton’s first success was in discovering a repair mechanism that could balance the process of erosion – a way in which the Earth might be rebuilding itself so as to constitute a lasting system. He did this by showing how the weight of accumulated sediments crushes and eventually melts the lowest layers of rock, causing them to erupt through volcanoes and so to rebuild the mountains.

This meant that the motions of the Earth could be seen as a continuous cycle, an effective ongoing process of maintenance, no longer a one-way path to decay. Hutton’s second achievement, which followed from this, was to show that the process was not a recent expedient but had apparently been going on for countless ages. It was a vast, steady, regular, reliable machine that showed, in his memorable words, ‘no vestige of a beginning – no prospect of an end’. It might even be something comparable to the eternal system which Newton had proposed for the heavens,

This was the point where the Earth began, once more, to appear as something understandable and therefore potentially respectable.

As Hutton’s friend Playfair wrote after seeing a rockformation that illustrated this vast process –

On us who saw these phenomena for the first time, the impression made will not easily be forgotten … We often said to ourselves, What clearer evidence could we have had of the different formation of these rocks, and of the long interval which separated their formation, had we actually seen them emerging from the bosom of the deep? … Revolutions still more remote appeared in the distance of this extraordinary perspective. The mind seemed to grow giddy by looking so far into the abyss of time.

Hutton’s explanation of these upheavals had at last made sense of the jagged contours of the Earth’s surface. The special music of those contours began at last to be heard. Unevenness which could not be understood in terms of space now became clear and reasonable when one added the dimension of time. And the sheer vastness of the time involved shifted the process away from the painful drama of human sin. Earth’s behaviour could now take its place on something more like the Newtonian pattern that was accepted for the celestial bodies.

This was great progress. Yet, beyond it, still another painful change was going to be needed – a change that brought in the perspective of history. Hutton’s notion of rationality required that the rhythm of the Earth’s movements should be – over a long time – as unchanging as that of the planets. There could be oscillations, but there could be no continuous cumulative change. And after Hutton, Charles Lyell formulated this same demand in terms of Uniformitarianism. Both saw this long-term unchangingness as a demand of reason. Yet later enquiry has not supported them. We now live in a model of continuous, cumulative, irreversible cosmic evolution.

The issue here is surely one of what you will accept as an explanation – what you are prepared consider as rational. To Lyell and Hutton, serious, lasting, irreversible change seemed simply contrary to reason. They found this form of music discordant and meaningless. According to Newton, change of this kind did not occur in the heavens and it ought not to do so on Earth. These geologists, having found processes that could reverse many supposedly permanent changes, understandably ruled that all change was reversible – as, indeed, it was assumed to be in physics until the discovery of thermodynamics, which occurred about the same time. The music of history, which constantly deals in unique events and irreversible changes, was then still an unfamiliar one. Thinkers such as Vico, Hegel and the inventors of thermodynamics were beginning to make it heard. But it still awaited its Beethoven in Charles Darwin.

Much of the shock that attended Darwin’s work was due to its treating the development of life as a continuous, directional change in this way. But the most disturbing point about it was, of course, that it brought human minds once more in relation to the Earth by tracing their descent from other animals. The scandal was not really due to an attack on God. (As Charles Kingsley said, God could just as well have created the world in one way as in another). Darwin’s real offence was to the dignity of man. He explicitly wanted to break down the fence that shut off our own species from other creatures. Being a true natural historian, he was deeply aware of kinship with the life around him. He thought this division was arbitrary and misleading.

Most of his contemporaries, however, still saw that division as an indispensable defence against chaos. Though the geologists had succeeded in bringing the Earth within the confines of science, they had by no means tamed its symbolism to the point where it could cease to be frightening. People might now be willing to speculate about the vast and distant processes that formed its history. But it was quite a different matter to be asked to acknowledge kinship with its non-human inhabitants. Those inhabitants – wolf, rat, worm, wasp, raven, serpent, ape – seemed to them chiefly embodiments of the vices. Here, once more, the Earth seemed to link them horribly with human sin. Once more, they shied away from it in alarm.

That symbolism, with its attendant horror, still persists today. It underlies, not just American Creationism but a wide range of confused objections to the idea of evolution. During the twentieth century, however, two things have weakened its grip considerably. One is the serious study of animal behaviour. The other is the discovery of continental drift.

On the one hand, ethologists have observed Earth’s living inhabitants carefully and have been able to testify at last that they are not, in fact, simply embodied vices. On the other hand, geologists – once they had accepted the alarming discovery that the continents move – have been able to add a further dimension of intelligibility to the state of the Earth’s surface by plotting these movements. In both these ways the Earth has gradually come to look less alien and more intelligible. And a third, more comprehensive, way of coming to terms with it has now been added to them.

It is surely no accident that the acceptance of these two advances has coincided with the rise of Gaia theory – the concept of an inclusive, self-maintaining system that involves both the Earth and its living inhabitants. These are both kinds of thinking that require a willingness to stand back from the jumble of detailed reactions to the Earth that pervades our experience and to consider it as a whole. They both call for large-scale thinking, for the leaping of barriers between academic disciplines.

In our age of academic specialization, this leaping is always hard. But in this case it has had a useful lift from the twentieth century’s experiments with Space. Astronauts who are trying to move away from our planet can no longer think of it simply as a background – a boring, dark, indefinite stuff that is always under their feet. Instead, they are forced to visualize it as a whole – as a planet moving through the sky – in effect, as one of the heavenly bodies.

They reported that seeing the Earth from a distance in this way is a quite astonishing experience, and the photos they took of it have to some extent conveyed that experience to the rest of us. They have deeply changed our response to the planet. Quite simply, they show it in its place in the heavens, as a body plainly entitled to whatever kind of honour and glory we associate with the Sun and stars. They finally expel the secret flat-earther who, till now, has apparently been lurking at the back of all our minds. They debunk the snobbery of height. Besides this, however – as has been pointed out – they show this Earth as having a distinctive honour of its own among the heavenly bodies in being visibly alive. It has a shimmering, multi-coloured surface quite different from that of the Moon and the other planets. It is a planet of which we need neither be afraid nor ashamed, and we ought now to find it easier to understand it.

Mary Midgley lectured at the University of Newcastle-upon-Tyne, before the Philosophy Department there was closed down. Among her best-known books are Beast and Man, Wickedness, The Ethical Primate and Science and Poetry. Her pamphlet Gaia: The Next Big Idea was published by Demos in May 2001.