Thomas Dixon. New Dictionary of the History of Ideas. Editor: Maryanne Cline Horowitz, Volume 4, Charles Scribner’s Sons, 2005.
The primary sense of the term natural theology rests on the contrast between natural and revealed knowledge. Natural theology concerns knowledge of the existence and attributes of God arrived at using only the natural faculties of sense and reason. Philosophical arguments for the existence, intelligence, power, and goodness of God based on the order and beauty of the world, or on purely intellectual considerations, are examples of natural theology. Knowledge of God that is based on divine revelation as set down in scripture is the subject of revealed theology.
A central metaphor for the distinction between natural theology and revealed theology is that of the “two books”—the book of God’s word (scripture) and the book of God’s works (nature). The mainstream theological position has always been that the primary source of truth was revelation and that natural reasoning—reading the book of God’s works—can provide ancillary support for revealed truths. Reason can confirm what is already known by faith. Natural theology has, therefore, been a more or less important, and more or less welcome, secondary support for Christian doctrine over the centuries. A constant worry for theologians has been the possibility of relying too heavily on natural theology and thus giving too much away to rationalistic and secular ways of understanding the world and placing insufficient emphasis on the importance of scripture and revelation.
Although the primary sense of “natural” in the phrase “natural theology” is natural as opposed to revealed knowledge, there is a secondary sense that is also important. Works of natural theology produced from the seventeenth to the nineteenth centuries frequently focused on the wonders of the natural world and on developments in natural science. The phrase “natural theology” thus came to stand for a rather particular kind of natural theology—a celebration of the beauty of the natural world and the power, wisdom, and goodness of its Creator, as revealed by the scientific study of nature. This sort of natural theology might also be thought of as a kind of “theology of nature,” to distinguish it from the broader intellectual enterprise of arguing about God independently of revelation.
Natural Theology and the Birth of Modern Science
Although it had roots both in ancient Greek philosophy and in medieval Christian theology (for instance, in Thomas Aquinas’s famous “five ways” of demonstrating the existence of God), the heyday of natural theology was between the seventeenth and nineteenth centuries and was intertwined with the rise of modern science (see Brooke, 2003; Brooke and Cantor).
Nature was investigated and interpreted in new ways in sixteenth-and seventeenth-century Europe. These innovations (which have traditionally been summed up as the “scientific revolution”) included the use of new scientific instruments (such as the telescope, the microscope, and the air pump), a new emphasis on experimentation, and the use of mechanical models to explain natural phenomena. The natural theological genre was one that both allowed practitioners of the new mechanical and experimental philosophy to justify their work to a sometimes skeptical religious establishment and also allowed religious apologists to enlist new knowledge in the service of Christian piety.
Many of the early members of the Royal Society in London (founded in 1660) saw a connection between their experimental investigations and their Christian faith. (Robert K. Merton famously argued that the Puritan religious beliefs of many of the founder members played a key role in shaping the activities of the Royal Society.) Robert Boyle (1627-1691), for instance, as well as conducting important experiments with his air pump to investigate the pressure of air and other gases, wrote on The Excellency of Theology, Compared with Natural Philosophy (1674) and composed a work entitled The Christian Virtuoso (1690), subtitled, “shewing that by being addicted to experimental philosophy, a man is rather assisted than indisposed to be a good Christian.” Another early Fellow of the Royal Society whose writings explored the way that the new experimental and mechanical philosophy could be used to support theology was John Ray (1627-1705), whose The Wisdom of God Manifested in the Works of the Creation (1691) was to become a classic of the natural theological genre. In this work, Ray argued that since the creativity of God was present throughout the natural world, no part of it was too low or insignificant to be a subject of natural-philosophical study.
The experimental investigation of nature in seventeenth-century England was, then, justified as being to the greater glory of God and for the good of man. The natural theology produced by men such as Boyle and Ray reflected the character of the new natural knowledge they were engaged in producing. Their God was an able mathematician, a geometer, a designer, a mechanic. If the experimental philosopher displayed his ingenuity by designing and constructing a telescope or a microscope, how much more ingenious must be the God who could design and construct the human eye? If the man of science gave evidence of his intelligence by discovering that natural phenomena were governed by elegant mathematical laws, how much more intelligent and powerful must be the God who drew up and laid down those laws?
In his will, Boyle left money to pay for a series of lectures to promote this natural theological vision, which he hoped would prove the truth of the Christian religion “against notorious infidels, viz. Atheists, Pagans, Jews, and Mahometans” (quoted in Brooke, 2003, p. 157). The result was a series of Boyle Lectures, which were delivered for around forty years, annually, starting in the year of Boyle’s death, 1692, when the first Boyle lecturer was Isaac Newton’s friend, the Reverend Richard Bentley (1662-1742). Another Newtonian and theologian, Samuel Clarke (1675-1729), was the Boyle lecturer in 1704-1705.
Natural Theology and Its Critics in the Eighteenth and Nineteenth Centuries
Lectures and treatises in this same natural theological tradition continued to be produced throughout the eighteenth century and into the first half of the nineteenth century, across Europe, but with a particular popularity in Britain. Natural theologians argued from the harmonious, law-governed, architecturally sophisticated, mathematically precise wonders of nature—animate and inanimate—to the existence and attributes of a good, powerful, and intelligent deity. Natural theological works frequently relied on arousing their readers’ aesthetic feelings, but these could then be used in support of very different political programmes, from Joseph Priestley’s and Thomas Paine’s versions of radical republicanism to William Paley’s and William Whewell’s more conservative Anglicanism.
The most famous philosophical critique of natural theology, David Hume’s (1711-1776) Dialogues Concerning Natural Religion, appeared, posthumously, in 1779. Although the use of the dialogue form meant that Hume did not claim any view directly as his own, some have thought that the arguments against natural religion voiced by the skeptical Philo are closest to Hume’s own views. In addition to throwing doubt on the soundness of the analogy between the universe and human artifacts, Philo suggests that if the analogy is to be taken seriously, then the correct inference should be to a cause more closely resembling the cause of human artifacts—namely, a being (or, more likely, a collaborating group of beings) of limited skill and foresight, not a single being of unlimited power and intelligence. Pressing the point even further, Philo asks why the natural theologian, once embarked upon the project of comparing human and divine designers, should not become a perfect anthropomorphite. Why not assert that the deity or deities has eyes, a nose, mouth, ears and so on, he asks.
Although the attacks upon the argument from design put forward in Hume’s Dialogues are often seen, in retrospect, as devastating to the natural theological enterprise, that was not how they were perceived at the time. The most famous treatise in the natural theology tradition postdated the Dialogues and did not consider the arguments put forward in them to be seriously troubling. This was William Paley’s (1743-1805) Natural Theology (1802), which is still considered the classic expression of the argument from natural design to divine designer. The Paleyite version of natural theology, with its focus on adaptation and design, was taken up by the authors of the Bridgewater Treatises. It was also the version of natural theology to which the young Charles Darwin (1809-1882) was introduced as a Cambridge undergraduate with a passion for natural history, in the late 1820s.
As the nineteenth century unfolded, however, the natural theology of Paley and the Bridgewater authors came under attack from a variety of different directions. Discussions about the intellectual status of natural theology overlapped with debates about the political desirability of church-dominated education. In Britain, for instance, the second half of the nineteenth century saw the Anglican monopoly on the universities and education being gradually eroded. Anglican men of science and their natural theological arguments were gradually displaced by agnostics and secularizers, with their more materialistic interpretations of scientific results, as the leading scientific authorities in Victorian Britain.
There had been, for some time, a radical, anti-Christian strand of natural theology—a deistic sort of natural religion promoted most famously by Thomas Paine (1737-1809) in his Age of Reason (1794-1807). On this view natural theology was not a supplement to revealed theology but a self-sufficient alternative to it. Paine argued that the book of nature was the only book that was needed to understand God and his creation. All churches, scriptures, and doctrines were anathema to Paine. Christianity was pilloried as a corrupt and oppressive system, run by a self-serving and power-hungry priesthood. The true theology—as opposed to the immoral superstitions of the churches—was to be found in the results of science and philosophy. Writing in the same freethinking tradition as Paine, but replacing Paine’s deism with outright atheism, the secularist campaigner George Jacob Holyoake (1817-1906), while serving a prison sentence for blasphemy, composed a pamphlet entitled Paley Refuted in His Own Words (1847). Holyoake pressed arguments similar to those put forward in Hume’s Dialogues seventy years earlier. Holyoake’s conclusion was that he had shown natural theology to be logically flawed, and thus also shown that revealed theology was groundless (since he held that revealed theology presupposed natural theology). He then went on to denounce Christian religion as a barrier to human progress and demand that it be replaced by a utilitarian and scientific secular morality.
Charles Darwin’s explanation in The Origin of Species (1859) of how the processes of random variation and natural selection could combine to produce what appeared to be instances of “design” in the natural world is often described as the final nail in natural theology’s coffin. If blind natural forces could create adaptation, then surely no role was left for Paley’s God. It was not quite that simple, however. Historians of science have shown that Darwin took over much of the language of natural theology (the discourse of “adaptation” and “design”) as well as some of its leading assumptions—such as the idea that every anatomical and behavioral trait should be assumed to have a function. Darwin was certainly no Holyoake. Whatever his own personal doubts about theology, he presented his ideas not as an argument for atheism but as an explanation of how the creator could make new species through the operation of laws rather than through miraculous interventions. Paley’s watchmaker-God may have been banished in Darwin’s new view of nature, but that had only ever been one of the images of God with which natural theologians had been concerned.
The Twentieth Century
Twentieth-century developments add weight to the view that Darwin’s writings, while requiring theologians to rethink natural theology, did not compel them to abandon it. One of the institutions through which natural theological endeavors were continued was the Gifford lectures. These lectures, set up to promote the study of natural theology, were instituted by the will of Adam Gifford, who died in 1887. Delivered in the Scottish universities of Edinburgh, Glasgow, St Andrews, and Aberdeen, by a range of distinguished philosophers, scientists, historians, and theologians since 1888, the Gifford lectures have resulted in a lively and ongoing series of natural theological reflections, conceived in the broadest sense. Gifford lecturers have included William James, Nils Bohr, Charles Raven, and Paul Tillich; and, more recently, the physicist and Anglican minister John Polkinghorne, historians of science John Hedley Brooke and Geoffrey Cantor, and the American theologian Stanley Hauerwas.
Discussions of natural theology have, ever since the mid-1930s, been carried out under the shadow of the figure of Karl Barth (1886-1968). In reaction to a 1934 treatise on Nature and Grace by Emil Brunner, Barth wrote a response titled simply No! In this and other works, Barth (and many others in twentieth-century academic theology who shared his dissatisfaction with nineteenth-century theological accommodations with scientific rationalism) emphasized the centrality of revelation and a religious relation to Christ. For the Barthian, rational argumentation undertaken on secular foundations could never produce distinctively Christian knowledge, and to suppose that it might was a theological mistake (regardless of whether it was also a philosophical and scientific one). Interestingly, both Barth and Brunner were subsequently Gifford lecturers; Stanley Hauerwas, in his recent Gifford lectures, argues in favor of a form of natural theology reconceived along Barthian lines.
Given the Humean, Darwinian, and Barthian objections to any form of natural theology grounded in the sciences, attempts to revive it in the later twentieth century certainly seemed to be doing so in the face of formidable opposition. Nonetheless, such attempts have been made. In the area of “science and religion,” authors such as Ian Barbour, Arthur Peacocke, John Polkinghorne, Bob Russell, and Nancey Murphy have argued that divine purposes can still be discerned in the findings of modern science. There has been particular interest in the question of whether the “fine-tuning” of the fundamental physical constants of our universe might indicate that it was made by a deity with an interest in creating intelligent life. Another area of lively revived natural theological speculations has been quantum physics.
In the United States, the twentieth century saw the invention of another new variety of natural theology, namely “creation science” or “scientific creationism,” whose advocates continue to resist mainstream neo-Darwinian orthodoxy and to call for “balanced treatment” of Darwinian science and “creation science” in the classroom. In this American controversy, not only the relationship between church and state but also the ancient question of the relationship between the book of nature and the book of scripture continues to be contested. Each group has its own view about this relationship. For creationists, revealed theology (specifically a literalist interpretation of the book of Genesis) and natural theology (specifically an anti-evolutionary interpretation of scientific evidence) concur in teaching that God created separate forms and that humans do not have a common ancestry with other animals. For other Christians, revelation and nature can be brought into harmony by reading Genesis less literally and accepting mainstream science. For others again—those who take a view like Thomas Paine’s—churches and supposed revelations are all nothing more than human creations: the only real source of transcendent knowledge is the study of the natural world, and the most fruitful means of studying it are science and philosophy. It thus continues to hold true that debates about natural theology are closely connected with debates about the relationship between church and state, especially in the area of education.