Natural Theology

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.