The Watch on the Heath: Science and Religion before Darwin. Keith Thomson

of underlying processes, their arguments had to change in response. Some of what they wrote – what they theorised, even what they thought was fact – might almost seem absurd to us now, but the work of people such as the Reverend Thomas Burnet, the Reverend John Ray, Dr Robert Plot, Dr William Whiston, Dr John Woodward, Dr James Hutton, Dr Erasmus Darwin and countless more, writing between 1665 and 1800, gives us an extraordinary glimpse into minds at the forefront of an epic enquiry. Many were deeply religious; all were consumed by the need to solve this potentially all-consuming challenge to their world view. They were often under immense pressure to conform with orthodoxy, even when their intellects pointed them in other directions. As well as admiring the force and elegance of the writing and the inventiveness of the arguments, we may also variously envy these earlier scholars their certitude, their daring, and often their humility and caution. It also becomes clear that this is not just a struggle between two sides; it is also a series of debates raging within both what we now call ‘science’ and ‘religion’.

      One of the many ironies about the conflict over the subject of evolution is that as a student Charles Darwin read and admired Paley, including his great work on natural theology. The final theme to this book is to trace out the powerful, direct connection from Paley’s belief that natural theology proved the impossibility of ‘evolution’ to Darwin’s championing of a critically important mechanism for the origin of new species.

       CHAPTER ONE Charles Darwin and William Paley

      ‘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