Читать книгу The Watch on the Heath: Science and Religion before Darwin - Keith Thomson - Страница 6

‘The Bible tells us how to go to Heaven, but not how the heavens go.’

Galileo Galilei, letter to the Grand Duchess Christina,

1615 (quoting Cardinal Caesar Baronius)

‘As it more recommends the Skill of an Engineer to contrive an elaborate Engine so as that there should need nothing to reach his ends in it but the contrivance of parts devoid of understanding … so it more sets off the Wisdom of God … that he can make so vast a machine [the universe] perform all these many things.’

Robert Boyle, Free Enquiry into the Nature of Things, 1688

One enters Christ’s College, Cambridge, through a richly carved sixteenth-century gateway and under a pair of painted heraldic beasts, all contrasting markedly with the sober courtyard of grey buildings within. Across the immaculate lawn, on the right-hand side of First Court, is the doorway to Staircase G with, on the first floor, the pair of rooms occupied by the shy young Charles Darwin when, between 1828 and 1831, he studied to become a Church of England cleric.

Much of Darwin’s early life, his ambitions and the sources of his inspiration, remain a mystery. He had originally started to train for medicine at Edinburgh but neither the subject nor the intellectual climate of the city suited him and in 1828 he entered Cambridge to prepare for a life as a clergyman instead. With his driving passion for natural history, he may have had in mind a career as a country parson-naturalist in the long tradition that had produced such luminaries as the Reverend John Ray (known as ‘the father of natural history’) in the seventeenth century and the Reverend Gilbert White, revered chronicler of English country life in the eighteenth. (Darwin’s cousin William Darwin Fox was also at Cambridge planning just such a career and soon achieved it, although his scholarly contributions from his quiet country parish were minor.) He may even have aspired to become a university don like his teachers in Edinburgh (Robert Jameson and Robert Grant) or his eventual Cambridge mentor the Reverend Professor John Stevens Henslow, a cleric, a brilliant teacher and a leading botanist and geologist. But if he were to take the route of training for the clergy, there was first the issue of faith.

Darwin had been brought up in the Midlands Unitarianism of his mother (the daughter of Josiah Wedgwood) while his father had long since taken the fashionable road to the Church of England. There is no question of Darwin having had a special ‘calling’ to be a clergyman. Indeed, when his father insisted that if he would not continue with medicine he must enter the Church, the eighteen-year-old had privately questioned whether he was sufficient of a believer honestly to start down that path, let alone to give witness to his belief in the pulpit.¹ But he needed a respectable profession. Therefore, in the summer of 1827, in his calm, preternaturally rational way, he set out on a research programme to discover whether he could go through with it. Darwin carefully studied the Reverend John Pearson’s Exposition of the Creed (1659)² with one question in mind, and ‘as I did not in the least way doubt the strict and literal truth of any word in the Bible, I soon persuaded myself that our Creed must be fully accepted’. Satisfied at a minimal level that he was not being personally or intellectually dishonest, Darwin entered Cambridge.

Darwin failed to complete his clerical training, just as he earlier failed to complete his medical studies. In 1831, armed with a passing degree and financially secure from his mother’s estate, he went off for five years’ adventuring and discovery on HMS Beagle. His religious beliefs then were still quite conventional: ‘I remember being heartily laughed at by several of the officers (although themselves orthodox) by quoting the Bible as an unanswerable authority on some point of morality.’ By the time he returned his career had taken a different direction, one in which the ceaseless questioning of science gradually replaced the sureties of revealed religion. But from very early on Darwin thought seriously about the developing conflicts between science and religion. As a student preparing to take holy orders, he knew of the challenges posed by early theories of evolution – particularly since one of them was the brainchild of his own grandfather, Erasmus Darwin. Later he would be only too aware that his own theory of natural selection, which he began to formulate as early as 1838, would inevitably contribute to the growing crisis caused by scholars who discovered, behind the apparent miracles of nature, the operation of scientifically definable laws and processes. And the situation was the more personal after his marriage in 1839 to his cousin Emma Wedgwood, who for her whole life was a staunchly believing Christian. At the time of writing On the Origin of Species, Darwin had lost his faith as a Christian and thought himself a deist; he died an agnostic and, while we cannot be sure exactly when Darwin first faced the challenges presented to conventional faith by contemporary science, we know that he was well aware of the issues in 1831, because we know what books he read.

In the spring of 1831, the tall, shy, aspiring cleric, a paradoxical mixture of bookish intellectual and outdoorsman with a passion for field sports, found himself with some time on his hands. Although he had achieved a respectable tenth place among students not competing for honours, he would not technically be eligible to graduate. He had to complete his required period of residency before entering the final year of study that would complete his formal preparation for ordination and a career in the Church. There was no question of his joining the ‘fast set’ at Cambridge and wasting his time with gambling and women. Typically, his mentor the Reverend Henslow prescribed a programme of reading: as a prospective ordinand in the Church of England, the young man of course read theology; as a keen naturalist and collector, especially of beetles, he read in travel and natural science. In his autobiography, written some fifty years later, Darwin singled out books from this period that had been most influential on his intellectual development. These included John Herschel’s Preliminary Discourse on the Study of Natural Philosophy,³ a book on the scientific method and the nature of scientific ‘proof’, and Alexander von Humboldt’s Personal Narrative⁴ of scientific exploration in South America. He also read the Reverend William Paley’s Natural Theology⁵, a treatise on the use of science to prove the existence, and demonstrate the attributes, of God. These three books, although very different from each other in subject matter, each dealt in their own way with the logic, philosophy and methodology of discovery and proof. Humboldt, whose work on the variation of climate with altitude Darwin had read at Edinburgh, helped fire his passion for exploration and discovery, and showed how the natural world could be explained in terms of natural laws. Herschel outlined the essential elements of a rigorous Baconian scientific explanation for any phenomenon, and it has been argued that the structure of Darwin’s own On the Origin of Species, published in 1859, was composed following Herschel’s rules exactly. In Natural Theology William Paley applied rigorous logic and a broad knowledge of philosophy to a wide range of contemporary scientific data in order to attempt nothing less than a final proof of the nature of God. This was a work intended to bridge two worlds that had long been threatening to pull apart. It would resolve the conflict that we find still unresolved today between, on the one hand, the world of scientific explanation expressed in definable, measurable, physical properties and natural laws and, on the other, belief in a God who transcends the material world.

William Paley’s theological works were well known to all students at Cambridge, where the syllabus included formal study of two of his books. Darwin, who had a particular appreciation for finely argued logic and reason, was examined on Paley in 1830 and said,

I am convinced that I could have written out the whole of the Evidences [Paley’s A View of the Evidences of Christianity, 1794] with perfect correctness … the logic of this book and as I may add of his Natural Theology gave me as much delight as did Euclid. The careful study of these works, without attempting to learn any part by rote, was the only part of the Academical Course which, as I then felt and as I still believe, was the most use to me in the education of my mind.⁶

Paley’s last book, Natural Theology, was not a set book for Cambridge examinations.⁷ It aimed for a broader audience than theologians alone and has come to occupy a special place in the history of science and religion. The basic premise of the larger movement of the same name was that the glories and complexities of living nature were to be seen as prima facie evidence of the power of God’s creative hand. From this viewpoint, which owes its origins among others to the Five Ways of St Thomas Aquinas, there could be no more pious endeavour than to study nature. All the patterns, symmetries and laws of nature were simply the reflection of God’s mind. Therefore to study nature was to approach closer to God. Indeed, the deepest study of nature would provide confirmation of God’s very existence. Natural science and theology were not at odds, therefore, but complementary. In particular, any kind of evolutionary theory of the kind that had been growing for the previous hundred years – in which the study of nature pointed to different, material causes of life in all its magnificent diversity than the hand of God – would be negated. At the time the young Darwin studied for the Church at Cambridge, as for a hundred years before, natural theology offered a rationale for the reconciliation of what might have seemed to be opposed: the diverse worlds of science and of religion.

This argument has a strong following today among those who would oppose, or are agnostic about the theory of evolutionary change. But, curiously, a direct connection can be traced between Paley’s arguments against any kind of evolutionary theories (of which there were many, termed ‘transmutation’, or ‘development’ theories, long before Charles Darwin was even born) and the origins of modern scientific thinking in favour of evolutionary theory. Darwin’s reading of Natural Theology in 1831 therefore has a particular resonance for anyone today who is interested in the question of how the apparently separate subjects of science and religion can be made one and, indeed, anyone interested in the historical precedents and intellectual origins of modern evolution.

Although many of the driving intellects of the age were continental – and this particular version of the battle between science and religion was being fought out elsewhere than Britain – this is a story about a peculiarly English part of the phenomenon, set squarely within a long English tradition. Its Englishness was due in large part to the long tradition of the English cleric-naturalists whose science was based in empiricism: from their rural parishes they observed nature and tried to read the word of God in it. They belonged straightforwardly to the new critical age and applied its rules and procedures to their thinking in God’s service. With many Church of England livings conveniently tied to the universities of Cambridge and Oxford, they had security and access to nature on the one hand, and on the other were a direct arm of the intellectual work of learning and teaching. Under the influence of the Enlightenment, they preached, they taught, they observed, and they considered it all. William Paley’s summation of the arguments of natural theology comes at the end of a great period of learning and adventure, with its freedom to entertain heretical ideas and no little reactionary conservatism, in which the evidence of nature as revealed by science was used to argue for the existence and nature of God.

Naturally, not everyone in the mainstream Church or its many dissenting offshoots approved of natural theology and attempts to prove God through science. The traditional route to discovery of God was through the authority of the Bible, divine revelation and the life of Christ. It was built upon the constancy of faith rather than the shifting ground of science. The paradox and the strength of faith is that it is not susceptible to cold-eyed analysis. No one knows if his faith is the same as another’s; almost by definition it cannot be. At the heart of Judeo-Christian tradition, the Bible reveals to us – individually or through the exegesis of its spiritual leaders – all that we need to know about God. It tells us that God is the Creator, all-wise and all-good, and is full of internal proofs, one of the greatest being that written in Isaiah 7:10–14: ‘Moreover the Lord spake unto Ahaz, saying, Ask thee a sign of the Lord thy God; ask it either in the depth or in the height above. But Ahaz said, I will not ask, neither will I tempt the Lord.’ Then God promised the ultimate evidence: ‘The Lord himself shall give you a sign; Behold a virgin shall conceive, and bear a son, and shall call his name Immanuel.’ For evidence, there were the miracles, both the biblical miracles – especially those wrought by Jesus, healing the sick, raising the dead, as he prophesied in the name of God – and those performed by God through his saints on earth. And the most dramatic demonstration of God’s existence and power would have to be the resurrection of Jesus, who in turn gave another real proof when he allowed the doubting Thomas, after the resurrection, to fit his hand into the spear wound in his side. No other authority than these was needed and an unguarded or naive person attempting to find God through the objective evidences of science might risk challenging traditional modes of authority and even be seduced by material explanations of phenomena to an opposite, atheistical position.

One can imagine circumstances when an attempt to prove God’s existence would have been heretical. A group of scholars probing nature to see if they can winkle out secrets about God that have been hidden – if God exists, then deliberately hidden – for thousands of years, seems a dangerous idea. In the year 1200, for example, not only would it have guaranteed the Pope’s or a bishop’s punishment; any sensible person would fear that God himself might exercise a little discipline too; after all, the Bible says ‘Ye shall not tempt [test or prove] the Lord thy God’.⁸ Or, as St Luke wrote: ‘This is an evil generation: they seek a sign.’⁹ In any case, to frame a series of questions and statements about his existence, unless done carefully, would be to risk limiting him to the small compass that our understanding allows. It also risked provoking further challenges to the literal truth of the Bible, already a problem in Enlightenment times. Close study of the Bible showed some worrying inconsistencies – two different versions of the Flood, for example, and two of the creation of Woman, together with much that is in disagreement with the facts of modern science. And why was so dramatic a sign as Thomas’s encounter with the risen Jesus (John 20: 24–28) not mentioned in any of the other three gospels? There was great danger in holding the Bible up to the same scrutiny, the rigid tests of independence, as used in the accepted methods of science.

But Paley was a man living in an age of science and reason. What might in medieval times have been considered dangerous or blasphemous – to prove something that required no proof – was now both acceptable and necessary. Philosophers such as Locke and Hume had long since exposed the vulnerability of religion founded not in fact but belief or faith, growing out of intuition, inspiration, hopes, fears and even myths. And, when Paley wrote in the dedicatory preface to Natural Theology that more and different proofs were needed because of the ‘scepticism’ concerning the existence and attributes of God ‘with which the present times are charged’, he could easily have been writing of our own day. The strength of his natural theology was that it did not depend on divine revelations and demanded no leaps of faith and suspensions of disbelief. Miracles are not mentioned in Paley’s book. Interestingly enough, neither is the Bible. Instead its argument depends upon a single, central argument in the form of a syllogism, summarised in his beautifully simple first paragraph. One can see instantly that someone like Darwin, who was attracted to logic and eager to see his inner doubts allayed, would be intrigued by this, the opening paragraph of Paley’s book:

In crossing a heath, suppose I pitched my foot against a stone, and were asked how the stone came to be there, I might possibly answer that, for any thing I knew to the contrary, it had lain there for ever; nor would it perhaps be very easy to shew the absurdity of this answer. But suppose I had found a watch upon the ground, and it should be enquired how the watch happened to be in that place … why should not this answer serve for the watch, as well as for the stone? … For this reason, and no other, viz. that, when we come to inspect the watch, we perceive, (what we could not discover in the stone,) that its several parts are framed and put together for a purpose, e.g. that they are so formed and adjusted as to produce motion, and that motion so regulated as to point out the hour of the day; that, if the several parts had been differently shaped from what they are, of a different size from what they are, or placed after any other manner, or in any other order … none which would have answered the use, that is now served by it … This mechanism being observed, (it requires indeed an examination of the instrument, and perhaps some previous knowledge of the subject, to perceive and understand it) … the inference, we think, is inevitable; that the watch must have had a maker; that there must have existed, at some time and at some place or other, an artificer or artificers who formed it for the purposes, which we find it actually to answer; who comprehended its construction, and designed its use.

In this analogy the watch stands for all living organisms; the ‘who’, of course, is God. A modern wristwatch is a dull, efficient affair. Paley’s watch would have been a large hunter or repeater enclosed within a silver or gold case. The back would hinge open to reveal a world in miniature of revolving gears in shining brass, tiny oscillating devices, and a great central spring, perhaps even (if a repeater) tiny bells to signal the quarter hours. The mechanics alone would qualify as a work of art as well as artifice. Paley’s conclusion leaps from the page: the springs, gear wheels and all the other bits and pieces of the watch represent the heart, the muscles, nerves, joints and all the thousands of tissues that constitute a living creature. If the watch and all its precisely interacting parts are made for a purpose, we are forced to conclude that we humans and all of living nature are also made to accord with a particular vision.

On the face of it, Paley’s premise is incontrovertible. A watch could not have appeared out of thin air. It did not chip off something else, as the stone might have done. It did not grow out of the ground like the grass on the heathland. Any machine must be made; in the case of something so intricate as a watch, it requires a detailed plan and a craftsman of great skill. And, given that it has been made so carefully, even someone who had never seen a watch before would conclude that it must have some purpose, a function. Every machine of human invention, all its parts neatly functioning, precisely adapted to each other and to the whole, must exist for a purpose. (If you set out to make a machine that had no purpose, then that would then constitute its purpose.) From this it follows that the more we study natural organisms – the elegant ‘machines’ of nature – the more we will learn about and confirm the power, purpose and goodness of the Creator. Construed thus, science is an exercise in piety and the sciences dealing with life on earth provide an unending catalogue of arguments about the existence and benevolence of the Creator.

The concept of the body as a machine would have been as familiar to Paley’s readers as the clockwork universe. A machine analogy for natural phenomena had long been a consistent element in Enlightenment philosophy. Leonardo da Vinci and the anatomists of the sixteenth century had seen the mechanical elements of a machine in the levers and pulleys of the skeleton and William Harvey, with the discovery of the circulation of the blood, made the body a dynamic mechanism. When Robert Boyle asked him what had inspired his discovery,

[Harvey] answer’d me, that when he took notice that the Valves in the Veins of so many sevral parts of the Body, were so plac’d that they gave free passage to the Blood towards the heart but oppos’d the passage of Veinal Blood to the Contrary: He was invited to imagine, that so Provident a Cause as nature had not so Plac’d so many valves without Design: and no Design seem’d more possible than that … it should be Sent through the Arteries, and Return through the Veins¹⁰.

Having given the outline of his case, on the very second page of his book Paley moved summarily to dispose of some easily anticipated criticisms.

Nor would it, I apprehend, weaken the conclusion, that we had never seen a watch made … Neither, secondly, would it invalidate our conclusions, that the watch sometimes went wrong, or that it seldom went exactly right … It is not necessary that a machine be made perfect, in order to shew with what design it was made … Nor, thirdly, would it bring any uncertainty into the argument, if there were a few parts of the watch, concerning which we could not discover, or had not yet discovered, whether they conduced to the general effect.

These are the sorts of objections that any reader might raise, especially as, in 1802, the mysteries of reproduction were still just that, everyone fell ill at times (Paley was seriously ill as he wrote the book), scholars had long wondered about the uses of the apparently functionless appendix, and so on.

Paley was concerned with far deeper issues than this, however. He launched into a debate with all the leading ‘atheistic’ positions of the day. In Paley’s typically eighteenth-century prose and sharp argumentation, the reader discovers a set of special issues and opponents. He fires off shots at a whole range of philosophers and philosophies, from Descartes to Locke, from Buffon to Erasmus Darwin. Their challenges to the foundations of Christian belief are both the immediate and eternal reason for his book. His special preoccupation is with what he considered the ultimate heresies – evolutionary theories. If Paley’s arguments were framed in terms unfamiliar to modern readers it is because we have variously absorbed and discarded Locke on understanding and Cartesian/Epicurean atomism, and Buffon’s and Erasmus Darwin’s ideas about evolution were long ago rendered extinct by those of Charles Darwin.

William Paley devoted his life, and particularly his great skills as a thinker and writer, to God and will long be remembered as the man who set out nothing less than a proof of the ‘existence and attributes of the Deity’. Natural Theology was Paley’s last book, written in his old age. While even the most assertive or arrogant of intellectuals might have hesitated at attempting to produce a definitive proof of the existence of God – and Paley’s book certainly shows itself as the work of someone who is very confident – in life he was modest and quiet, a somewhat shy, shambling figure, built short and square, and by 1800 suffering terrible pain from what was probably abdominal cancer. The only known portrait shows a man with a smile to light up even the most dreary northern winter day. His deep, quiet voice – always too soft for a properly dramatic manner at the pulpit – was the voice of calm and reason. As a student, he had never dreamt of adopting the citified modes of speech of Cambridge and London. His rough-hewn manner allowed him to speak directly to his flock and no one criticised or mocked his outmoded coat, his old-fashioned hat or his wrinkled stockings. At his prime, his sermons persuaded, cajoled and inspired rather than insisted or threatened. Those sermons, like his life, were full of wit and wisdom and coloured with just enough liberal thinking to make his superiors uneasy. As for inspiration, he never hesitated to build upon the works of others, indeed he mischievously advised young clerics: ‘if your situation requires a sermon every Sunday, make one and steal five’. Towards the end of his life he walked with a broken, rolling, seaman’s gait and would stop occasionally to recite aloud snatches of poetry or to sing.

He was born in 1743, the first child and only son of William and Elizabeth Clapham Paley. His father was headmaster of Giggleswick School and his mother a fine, intelligent woman, noted for her thrift. From them he inherited a flair for mathematics and a love of argument. Fifty-five years before Charles Darwin, he too entered Christ’s College, Cambridge, where he graduated first of his class (‘Senior Wrangler’) in 1763 and then stayed on as Fellow of the college, teaching philosophy and the Greek Testament. From the very first a brilliant and much-loved, if unconventional, teacher, he was ordained in 1767. But the celibate life of the university don was not for him and in 1776 he married Jane Hewitt of Carlisle and became a clergyman and writer. His teaching at Cambridge had been so successful that his friends pushed him to publish his lectures, some of which had formed the basis of his first book, The Principles of Moral and Political Philosophy (1768).¹¹ This book alone would have earned him a place in history, enjoying some twenty editions in his own lifetime. Morals was followed by an influential study of St Paul and then, in 1794, Paley wrote a third book, arguably greater still. A View of the Evidences of Christianity12 set out to show, conclusively and incontrovertibly, proofs of the historical truth of Jesus and the truth of his revelations. In this book, Paley put aside the exhortations of the pulpit in favour of the forensic techniques of the courtroom lawyer – a style that came very naturally to him. After graduating from Cambridge, he had for a while taught at a school in London. There he spent his spare time equally at the theatre and the law courts. Both seem to have polished his rhetorical skills. He may even have been seriously tempted by the field of law and become a leading barrister at the Inns of Court; for his was a mind drawn naturally to logic, and to proofs and precision; instead he became a barrister for Christ.

In Evidences, he took the role of counsel for the prosecution, basing his case on evidence from four witnesses, the authors of the gospels. The lives, and not least the terrible deaths, of the Apostles and the other early martyred saints of the Church provided reason enough to believe, resoundingly answering the atheists’ jibe: ‘Either the Apostles could not write more intelligibly of the reputed Mysteries or they would not’.¹³ Paley also insisted upon the authenticity of miracles as the vehicle for God’s revelation of himself to man. They were an integral part of God’s design and the essential mode by which God could communicate with the works of his Creation. ‘Now in what way can revelation be made but by miracles? Consequently, in whatever degree it is probable or not very improbable that a revelation should be communicated to mankind at all, in the same degree it is probable or not very improbable that miracles should be wrought.’

Morals and Evidences brought Paley fame and a certain fortune and both became set books for examination of Cambridge students. (Remarkably enough, the last Cambridge students to be held responsible for the contents of Evidences sat warily down to their desks in 1920.)¹⁴ But he never attained the bishopric that would have seemed the natural preferment for so revered a teacher and preacher. His highest appointment was Archdeacon of Carlisle. While his parishioners loved him, his peers may have found him just a shade too brilliant and too free with his ‘almost too unlimited indulgence of wit and drollery’ – for example in that advice to young clerics over sermons.¹⁵ In Morals he had sided with Locke, whose work he had taught at Cambridge, over the right of people to revolt when their government failed in its responsibilities, a position he later abandoned in Natural Theology. And in one respect he was his own worst enemy – he refused to engage in ‘rooting’, his term for cosying up to people for influence. Nonetheless, the father of his great college friend John Law was Dr Edmund Law who, as Bishop of Carlisle, put a series of comfortable absentee livings his way, making sure that he had the security and contentment to write. The awkward man with his unfashionable accent and deep country manners was free to pour forth his brilliantly crafted texts, creating an intellectual achievement that has survived more than 200 years.

Evidences, with its insistence on the power of divine revelation, is obviously a mainstream Christian book, its goal to provide an independent line of support for the revelations that form the mainstay of Christian belief. It is often said of such books that their principal role is to comfort and confirm the believer rather than to persuade the atheist or sceptic, but in Paley’s case this would be a cheap sneer. His technique was not to appeal to faith but to reason. All Paley’s books are part of the maelstrom of ideas and movements that framed the Enlightenment and the Age of Reason. His 1802 masterpiece on God, through the strict logic of its author with all its strengths and flaws, visits the science of the age and the countervailing resistance of the natural world to simple arguments and neat solutions. Its full title is Natural Theology: or Evidences of the Existence and Attributes of the Deity collected from the Appearances of Nature. When, with the customary deference of the day, he dedicated his book to his bishop, Paley was at pains to point out that the work was intended to form a whole with his others, ‘a system … the evidences of natural religion, the evidences of revealed religion, and an account of the duties that result from both’. In fact, in Natural Theology a different, more liberal, Paley emerges, carefully writing to persuade the deist or Christian alike. For an analytical reader like Darwin, the differences between Evidences and Natural Theology were striking.

The logical basis of Paley’s argument would have been familiar to Darwin. The watch analogy was a syllogism, depending on the first two ‘Rules of Reasoning’ that Newton had laid down in his Principia Mathematica of 1687, the foundation stone of modern science: ‘We are to admit of no more causes of natural things than such as are both true and sufficient to explain their appearances [and] … Like effects proceed from like causes.’ Whether Paley can be thought truly to have abided by the first principle is debatable. What is true and sufficient is something to be determined, not taken for granted, in this debate. Newton’s second rule gives greater support to the argument: ‘Like effects [complexity] proceed from like causes [a maker].’ However, the Scottish philosopher David Hume, among others, had already given the case against this kind of thinking:

When we infer any particular cause from an effect, we must proportion the one to the other, and can never be allowed to ascribe to the cause any qualities, but what are exactly sufficient to cause the effect. And if we ascribe to it farther qualities, or affirm it capable of producing any other effect, we only indulge the licence of conjecture without reason or authority.¹⁶

Elsewhere he wrote: ‘There can be no demonstrative arguments to prove that those instances of which we have no experience, resemble those, of which we have had experience.’¹⁷ In other words, one cannot be confident in explaining what we do not know from what we do know, because we don’t know what it is we don’t know. Time and again we find the sciences, like other disciplines, exhibiting just this weakness, with false conclusions being drawn because of an incomplete vision of possible causes that in turn limits the imagination. It took Einstein, for example, to break the belief that light invariably travels in straight lines; he could conceive of something others could not (before it could be shown empirically).

The odd thing is that William Paley was not really a ‘scientist’ (a natural philosopher). He was not known as a naturalist, he did not collect insects or fossils as did so many of his colleagues, although he very much enjoyed angling. Although he had no training or experience in medicine, astronomy, chemistry or geology, the task he set himself was to turn the ploughshares of science into swords of religion. His dilemma, brilliantly resolved, was to find a way to use the contemporary fashion for rationality and science to make a case for God, when many scholars thought that philosophy and discovery were pointing in the opposite direction. He had not just to reconcile science and religion, but to use science to support, indeed to confirm, a belief in God; and not in some rearguard action, but a major offensive. For Paley, there was no luxury of time, however. Instead, there was a terrible urgency; he had to turn the scientists and philosophers against themselves before they could overwhelm his world. He had to affirm the existence of the Creator without getting caught up in contemporary arguments about biblical authority and the literal truth of every word of the book of Genesis. And he had to take on some of the greatest philosophers of the age.

Although they ended up on opposite sides of the issues of God, creation and life, Paley (in 1802) and Charles Darwin (starting around 1838) had to confront very similar problems. Both suffered the disadvantage of trying to make an incontrovertible case without the kind of irrefutable empirical evidence we usually describe as a ‘smoking gun’. They had to convince by argument because they could not ‘prove’, and therein lies a restatement of Paley’s dilemma: were his arguments founded on scientific fact or pious belief? Were they the long-sought-after proofs or only the familiar old assertions and appeals to faith? Darwin, in turn, could describe natural selection but no one had seen the origin of a new species actually happen. And for both men, the growth of scientific explanations of material phenomena conflicted directly with established beliefs and the teaching of the Church. For Darwin, having at least started to train for the Church, the burden of his discoveries was so great that it made him a physical invalid. He knew the consequences of his theory and the effect it would have on religion and thus the very fabric of society. It would set people against each other; it would set him against his own wife. If his theory proved too revolutionary, it would be rejected out of hand. He would become an outcast and all his efforts would be for nought. He delayed publication for more than twenty years until he thought the ground had been sufficiently prepared for his radical theory of an evolutionary mechanism that would cut the intellectual ground from under the feet of all the natural theologians.

Perhaps, then, there is a nice irony in the fact that when he went up to Cambridge and reported to the porter’s lodge just inside that great gate, the young Charles Darwin was assigned to the same rooms in Christ’s College that Paley had lived in seventy years before.