The Watch on the Heath: Science and Religion before Darwin

Nicolas Copernicus (1473–1543) in his De Revolutionibus Orbium Coelestium (published the year he died), forced the world to consider the heliocentric model in which not only does the earth revolve around the sun, but it also rotates on its own axis every 23 hours and 56 minutes. (Alternative models had proposed that, for example, the sun and planets stay still and the earth revolves, or that the sun and moon go round the earth and everything else goes around the sun.) Precise measurements made by Tycho Brahe (1546–1601) helped Johannes Kepler (1571–1630) make a new kind of astronomical sense. The movements of the planets – one of the great mysteries of the universe – could be boiled down to three very simple laws, all depending on the fact that their orbits were not circles but ellipses, all around the sun, except for the moon, which orbits the earth. The central consequence of Copernicus’s revolution is only too obvious to us today. Not only had the earth been displaced from the centre of the universe, it had become merely a tiny speck of matter in the immensity of space, no more or less perfect than the rest.18

Copernicus died in 1543, leaving others to take up his work. Galileo Galilei was born in 1564 and acquired an immortal place in history for being forced by the Inquisition in 1633 to recant his belief in Copernicus’s heliocentric universe. When he made his first telescope in 1609 and looked at the moon, he had started another revolution, discovering that it is not the ideal body that the ancient Greek philosophers had believed and every poet had romantically declaimed; instead, it was ugly and broken, pockmarked with craters and rifts. Perhaps even worse, he saw that the sun, which from time immemorial had been seen as a perfect sphere giving light and life to the earth, was also imperfect. In the Bible, it forms one of the great metaphors for the coming Messiah: ‘The sun of righteousness shall rise with healing in his wings’ (Malachi 4:2).19 Galileo discovered that the sun is blemished, with dark spots that move, apparently randomly, about its face. (His opponents argued that since these spots could only be seen with the telescope they must have been artefacts of the lenses.) Shortly afterwards Galileo observed that Jupiter has its own planets and that Venus shows itself in phases, like our moon. He realised that, beyond the visible planets and fixed stars, there were millions of other stars, not visible to the naked eye, and who could guess what lay beyond those. In this new concept of the heavens, the earth and its inhabitants really were minor in significance. Perhaps there were even other worlds such as ours, with other sentient beings, and we were not alone in inhabiting the cosmos.

Although he was surely as complex a character as any other haunting the corridors of power and influence in seventeenth-century Italy, Galileo has become one of the more sympathetic characters in scientific history, an honest man cruelly oppressed by the enforcers of religious and intellectual orthodoxy.20 Isaac Newton, on the other hand, presents much more of an enigma; a brilliant scientist whom we very much want to admire, but also a dark, brooding man, his personality seemingly pinched and bare. It is odd that such a profound intellect should have been so insecure about money and position, so temperamental and suspicious. While his ideas on motion have endured, his works on alchemy and vitalism have not. And he managed to gather about himself a host of eager rivals and competitors and suffered cruelly from the common problem that major discoveries seem to come in bursts, often being developed quite independently by more than one person at the same time. Many a schoolchild has damned Newton for inventing the accursed calculus (which he called ‘fluxions’) that he and Leibnitz invented independently. Newton was not helped by his great brooding sulks; he would start work on a subject, become dissatisfied because the answer didn’t satisfy his own high standards, and then put it aside for a few years. Meanwhile others would be closing in on a solution.

England’s greatest scientist, Newton was born in 1642, the year that Galileo died. He took over the science of Galileo’s time and created a new intellectual sphere, a new world of mechanical laws with which we are still far more comfortable than we are with the modern world of quantum physics, where Einstein’s relativity and Heisenberg’s uncertainty reign. The ancients, particularly Aristotle, had thought that all matter was naturally at rest unless acted on by another force. This is again a weighty piece of common sense: when we see a stone on the ground, it does not move until we kick it. The question is, why does it then slow down and stop? Newton rewrote the science of motion and mechanics in a masterpiece of uncommon sense and mathematical precision.21 He showed that all matter is in uniform motion (constant velocity, including a velocity of zero) unless acted on by an external force. Exactly opposite to Aristotle’s view of motion, Newton showed that an object will remain still or continue to move at a constant speed in the same direction unless some external force changes things. A moving stone slows down because a force of friction has slowed it, not because it somehow wants naturally to come to rest. A thrown stone describes a parabola through the air, not because it naturally tends to progress in a perfect theoretical circle, but because a force – gravity – has diverted it from the direction in which we threw it. Single forces always act in straight lines, not circles. Any trajectory other than a straight line must be the result of multiple forces acting together.

One of Newton’s most brilliant insights (with the assistance of Robert Hooke) was that the mechanism that keeps the planets in their elliptical orbits around the sun according to the rigid rules discovered by Kepler is the same as that which controls the fall of an apple from a tree, or shapes the trajectory of an arrow shot from a bow. From this he could predict that a projectile fired into the sky at a high enough velocity would continue indefinitely straight out into space. But one fired at some lower velocity would be attracted back to the earth by the opposing force of the earth’s gravity, and if the two sets of forces balanced, then the projectile would settle into orbit around the earth – just as the earth and the other planets orbit the sun, and just as the moon and communication satellites orbit the earth.

Nothing would be the same after Newton’s strict mathematics. Not even the simplest aspect of daily life on earth could be considered immune from the laws of science and the probing of scientists. Kepler’s laws of planetary motion might be glossed over as remote and literally other-worldly but Newton’s laws of motion touched every intimate detail of existence and were correspondingly subversive. Newton accelerated one of the great movements in science – which is to take the mystery out of everything. He also helped to explain some of the contemporary puzzles in the heliocentric model of the universe. If the earth is hurtling through space at many thousands of miles per second, why are we not all blasted off by the wind? If the earth revolves, and those in the northern hemisphere are standing up, why don’t the upside-down Australians fall off? The answer is that gravity holds our atmosphere in place, so there is no cosmic gale, and it holds the Antipodeans in place too. For everyone, ‘down’ is towards the centre of the earth. Science had given nature a new uncommon sense. And, in addition to the technical importance of Newton’s mathematics, the concept of a ‘balance of forces’ keeping the moon circling the earth and the earth in orbit around the sun, very quickly became a valuable metaphor for the description and explanation of a wide range of secular phenomena, including Malthus’s ideas about population growth being held in check by negative factors and Darwin’s ideas on evolution.

Newton’s emphasis on matter and motion related centrally to the Epicurean school and their theories of the nature of matter itself. These ideas had been revised and extended in more modern times by the great French philosopher Descartes (René des Cartes, 1596–1650) whose physical theories Newton in turn largely supplanted. Beyond Galileo’s collision with the Inquisition, if any one man could be said to have started the fields of science and religion on their course of conflict (or perhaps simply of divergence), it is Descartes. By sheer force of intellect and powerful original thought, he created a whole new approach to philosophy, brilliantly turning upside down the old, classical authorities to which the Church turned for support during the Middle Ages. Born in France and educated at the Jesuit college at La Fleche in Anjou, Descartes was Galileo’s younger contemporary and a philosopher who wrote about everything from pure mathematics to human physiology, from the origins of the solar system to the fundamentals of human understanding. All his philosophy started with rejection of previous authority, none of which could be as reliable as one’s own senses and intuition. Every schoolchild knows (or should know) his dictum: ‘Cogito, ergo sum.’ These three words, translated as ‘I think, therefore I am,’ represent his last resort after having rejected everything else in an attempt to find an incontrovertible reality – a truth – upon which to base a philosophical system.

The rigour of his methods was grounded first in mathematics: ‘Those who are seeing the strict way of truth should not trouble themselves about any object concerning which they cannot have a certainty equal to arithmetical or geometrical demonstration.’ Galileo, in one of his most famous passages, had put things even more eloquently: ‘Philosophy is written in that great book which ever lies before our gaze – I mean the universe – but we cannot understand if we do not first learn the language and grasp the symbols in which it is written. The book is written in the mathematical language … without the help of which it is impossible to conceive a single word of it, and without which one wanders in vain through a dark labyrinth.’22

As a young man Descartes wandered the capitals of Europe before settling in Holland in 1628. From the beginning he thought intensely about epistemology: the question of how we know, and especially how we can find ultimate, objective ways of knowing what is right and true. Again this turns on his basic premise, ‘Cogito, ergo sum.’ In his Meditations he turned this into a long argument for why God must exist, why God is perfect, and why God has made man in his own image. In considering the workings of the human body, he drew a firm line between animals and ourselves. Humans alone have a dual nature – a material body and an immaterial soul – and that distinguishes us from the rest of creation. This was a distinction that carried far into the nineteenth century even as people began to discover the workings of the nerve impulse and the brain and as they delved into the nature of consciousness; until they began to find that the old line between animals and humans was as blurred in this regard as in every other. Descartes’ physics of the universe was based on the idea that the planets were suspended in a total void and that their motions described a series of vortices. Like Newton’s mathematics of forces acting in straight lines, which replaced them as a description of the cosmos, vortices had a strong metaphorical as well as actual ring to them. But Descartes did not believe that bodies could influence each other except when in contact. By dismissing ‘action at a distance’, and therefore phenomena such as gravity, while having moved ideas forward mightily, he failed to create a truly modern physics.

In his cosmology, Descartes began with an Epicurean physics, seeing the world arising out of atoms in motion. Democritos (c. 460–371 BC), in perhaps one of the most prescient pieces of pure intellect, had taught that: ‘Nothing exists except atoms and empty space; everything else is opinions.’ In this atomic theory, all the various kinds of matter differ only in the size, shape and motion of their infinitesimally small atomic constituents. In Descartes’ atomic-deist theories, creation was originally a series of events during which order condensed out of this random atomic behaviour. All matter – whether rocks, trees or monkeys – is merely the combinations of these atoms churning through space, driven by chance. God then had been relegated to the maker of the atoms and the formulator of the broad rules of their motion. By Paley’s time, despite the failure of the theory of vortices, Descartes was popular with deist scientists trying to find new truths about the cosmos in the spirit of the Enlightenment and Age of Reason, but was dismissed by traditional theologians as one of the ‘ancient sceptics who have nothing to set against a designing Deity, but the obscure omnipotency of chance, and the experimental combinations of a chaos of restless atoms’.

In parallel with such philosophical approaches to knowledge itself and new theories about the very state of matter, a fresh style of experimental science flowered in the modern intellectual environment. Deep thought and practical experimentation fed off each other; as one scholar probed into how we know, another tinkered with new devices for observation and discovery. One man in particular helped launch this empirical renaissance. Francis Bacon (1561–1626), in his Advancement of Learning of 1605 and Novum Organum (1620), laid out a template for science to proceed by the accumulation of facts and by the framing of rational, testable hypotheses. This empirical approach was based on the revolutionary notion that truths about the material world should be discovered rationally through experiment, observation and analysis rather than derived from a set of classical philosophical abstractions or presented as a matter of divine revelation. In Novum Organum he wrote: ‘There are and can be only two ways of searching into and discovering truth. The one flies from the senses and particulars to the most general axiom … The other derives axioms from the senses and particulars, rising by a gradual and unbroken ascent, so that it arrives at the most general axioms last of all. This is the true way, but as yet untried.’

Perhaps nothing better exemplifies the new spirit of empiricism that flourished in the second half of the seventeenth century than the experiments of Robert Boyle and his colleague Robert Hooke, two of the most brilliant natural philosophers of their age, who worked together as equals but in origins and personal style were as different as they could be. This was the first generation of natural philosophers who could be considered ‘scientists’ as we understand the word. The Honourable Robert Boyle was the wealthy son of the even more wealthy 1st Earl of Cork; Hooke came from a family of more modest means: his father was a parson who died young. Boyle, educated at Eton, did not attend university. From an early age he had been an avid reader and after schooling at Eton was tutored privately, first in England and then, from the age of fourteen, in Geneva. Back in England at eighteen, he took up chemistry and then settled in Oxford where he built a laboratory and hired the young Hooke to assist him. In pictures painted in his middle age, he looks a magnificent rich dandy, tall, haughty and remote, but in reality he was a frail man, often ill, with a stammer and a mild, kind, generous and refined intellect, to whom many potential honours, including a peerage, were offered. After leaving Oxford for London, in part to take a greater role in the Royal Society, his intellectual interests ranged well beyond the laboratory to philosophy and particularly to the promotion of religion. If anyone of his age had the right to be called a true philosopher of nature, it was Boyle. He never married but lived most of his adult life with his sister Lady Ranelagh. When she died in 1691, he died just a week later.

Robert Hooke, born in 1627, was eight years younger than Boyle. He was born on the Isle of Wight, where his father was vicar of Freshwater. He soon showed an advanced ability in drawing and everything mechanical, but had to make his own way in the world at thirteen, following the death of his father. A small inheritance allowed him to become an apprentice to the painter Sir Peter Lely in London but Hooke soon decided that he had enough skill in that direction without the drudgery of apprenticeship. He entered Westminster School, where he demonstrated an amazing ability to master languages, learnt ‘the six books of Euclid in one week, mastered the organ in twenty lessons, and invented thirty ways of flying’.23 He became an undergraduate at Christ Church College, Oxford, in 1653 where, essentially penniless, he was forced to earn his way as a servant to another student. Nevertheless, he soon made his abilities known to all the scientific luminaries of the age including Christopher Wren and Robert Boyle.

Boyle and Hooke made a superb team, with complementary skills and an equal commitment to the new-fangled Baconian idea that the truth could be found through direct observation and experiment.24 During the twelve years they worked together at Oxford between 1656 and 1668, Boyle and Hooke’s ideas led in every direction. They became particularly famous for investigating the properties of air, which in classical and medieval times was one of the four ‘elements’ (air, earth, fire and water). Using their own version of the air pump that had been invented by Otto von Guernicke, they measured the elasticity of air and found the mathematically precise, inverse relationship between the volume and pressure of a body of air. This is one of the first physical laws to be enunciated and is still known today as Boyle’s law. Boyle’s air pump, built and operated by Hooke, was also intended to show that Aristotle was wrong when he taught that a vacuum was impossible in nature. Attached to their pump (which often broke down) was a glass chamber inside which they could create both high pressure and a (partial) vacuum. They proved that when the air was removed from the chamber, sound could not be transmitted, although light could. A whole mini-revolution was seeded by what might seem to us a very simple piece of apparatus when they also used it to conduct some elementary experiments on the effect of the air on living organisms, putting a bird or mouse into the chamber and evacuating the air. As it was withdrawn, the animal became listless; if the air was restored, it revived. If enough air was withdrawn, the creature died: all commonplace stuff to us, but revolutionary then. They had discovered that there must be some ‘vital essence’ in the air that makes life possible. This, and the eventual discovery of oxygen by Lavoisier, Joseph Priestley and others, launched an investigation into the material (physiological) basis of life itself, a subject with enormous metaphysical implications given that it had always been thought that life was something breathed into creatures by God, not just another property of matter in motion.

Linguist, microscopist, artist, mathematician, mechanical experimenter and inventor, palaeontologist, surveyor – Hooke’s accomplishments were long overshadowed by the fame of the two other geniuses (Boyle and Christopher Wren) with whom he worked. With Boyle he was the master experimenter and inventor – for example of the universal joint, essential to so many modern machines.25 With Wren he was the great engineer. When Wren was made architect for the rebuilding of London after the Great Fire of 1666, Hooke was the chief surveyor; and as Hooke the engineer he gave Wren the parabolic formula for the great dome of St Paul’s Cathedral.26

For a period after Boyle left Oxford, he continued to employ Hooke, who became the ‘curator of experiments’ for the Royal Society and therefore found himself (or made himself) for the rest of his life at the centre of every scientific discovery of the age. Sadly, few people seem really to have liked Hooke, whose childhood kyphosis steadily worsened so that as an adult he became a twisted hunchback. Something of a miser and a misanthrope, and never one to avoid a fight or to allow someone else to take credit for his own discoveries, he became extremely litigious. He contested bitterly with Christian Huygens over the invention of the spring-regulated mechanism that made a pocket watch (and thus Paley’s famous metaphor) possible, and he argued bitterly with Newton over optics and cosmology. When Newton took over from Hooke as President of the Royal Society, Hooke’s portrait mysteriously disappeared from the society’s rooms.

The combination of Newtonian mechanics, Baconian methods, and the new experimental empiricism that propelled eighteenth-century science was also reflected in the Industrial Revolution and is exemplified in the extraordinary career of William Paley’s contemporary, Erasmus Darwin (1731–1802). This Darwin, grandfather of Charles, was a successful doctor in the city of Lichfield and at the same time a member of the famous Lunar Society of the industrial Midlands. Darwin, Watt, Boulton, Wedgwood – all the great names of British inventiveness – met once a month and created a new kind of intellectual centre outside the universities.27

Erasmus Darwin was not just a brilliant doctor, a trencherman (he weighed some eighteen stone) and sensualist (fathering fourteen children, at least two out of wedlock), he was also a remarkable inventor. Designs for steering mechanisms and sprung wheels for carriages, a steam-driven carriage, improvements to steam engines, a horizontal windmill, the canal lift, hydrogen balloons to carry mail, a clockwork-driven artificial bird, a copying machine, a turbine engine, a multi-mirrored telescope, a water closet, devices for improving gardening, new kinds of spinning machines – all flowed from his pen. Furthermore, he was also a poet and radical philosopher who used his poetry, tending to the epic in style and volume, as the vehicle for his most dangerous ideas.

One of the themes of Erasmus Darwin’s immensely popular works concerned what we now call evolution, a subject more commonly associated with his grandson. Like so many of his century, Erasmus Darwin was fascinated by fossils and the extraordinary record they presented of life and death over the ages. Darwin saw that they were evidence of the life and death of legions of organisms never seen alive by man: extinct forms about which the Bible is totally silent. Fossils were evidence of a whole ancient world waiting for scientific explanation. Without knowing how much time might have been involved, and ignoring the biblical narrative of creation, Erasmus Darwin proclaimed a world of gradual change over the aeons; change from simple creatures to more complex; life arising out of chemistry, driven by the forces of the environment:

Earths from each sun with quick explosion burst,

And second planets issued from the first.

Then, whilst the sea at their coeval birth,

Surge over surge, involv’d the shoreless earth, Nurs’d by warm sun-beams in primeval caves,

Organic life began beneath the waves …

Hence without parent by spontaneous birth

Rise the first specks of animated earth.28

‘Without parent’! No amount of argument could make that idea compatible with ‘God the father’ and the most honoured of all words in the Old Testament, the first verses in Genesis, which state that God created the world exactly as we know it, in six days. Erasmus Darwin had issued a challenge in the style of a dictum of Descartes, who had once said: ‘The nature of physical things is much more easily conceived when they are beheld coming gradually into existence, than when they are only considered as produced at once in a finished and perfect state.’ Other scholars in France and England shared this vision of a changing world, but ‘gradual’ and ‘chemistry’ were not in the Church lexicon. Paley read Erasmus Darwin, recoiled, and reached for his pen.

Even more threatening to Paley’s world view was the quickly growing sciences of the earth, brilliantly synthesised by James Hutton, a Scottish doctor, farmer, philosopher and geologist who, in 1795, published a two-volume Theory of the Earth.29 If any single book captured the challenges posed by the new science, it was this. Genesis says that the physical world was created in three days and populated by animals and plants by the sixth. Learned clerics had even devised elaborate schemes to decode the histories recorded in Genesis to arrive at a date for this great event – 4004 BC. But dozens of equally learned men who had been investigating the nature of the earth itself had produced a different kind of authority in new empirical data as well as theory. Hutton distilled the results of a hundred and fifty years’ enquiry into the structure of the earth and the processes that shaped it, and dared to suggest a totally different conclusion: that the world was unknowably old.