Paley's argument exemplifies one of the high points of so-called "natural theology," a field that, in its classical heyday, sought to prove the existence of God and even to illustrate aspects of God's character without any appeal to scripture.

"In crossing a heath," wrote William Paley at the beginning of his famous 1802 book "Natural Theology," "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 show 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, I should hardly think of the answer which I had before given, that, for any thing I knew, the watch might have always been there."

"Yet why should not this answer serve for the watch, as well as for the stone? why is it not as admissible in the second case as in the first? For this reason, and for 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 … This mechanism being observed … 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 purpose which we find it actually to answer; who comprehended its construction, and designed its use."

Paley then proceeded to point out many features of the natural world that, in his judgment, virtually compelled the conclusion that nature itself had been framed for a deliberate purpose.

His argument exemplifies one of the high points of so-called "natural theology," a field that, in its classical heyday, sought to prove the existence of God and even to illustrate aspects of God's character without any appeal to scripture.

But Darwin's theory of organic evolution — his "Origin of Species" was published in 1859 — dealt natural theology a serious (and, some think, fatal) blow. Neither design nor a designer seemed necessary any more to account for the complex variety of the natural world. "Although atheism might have been logically tenable before Darwin," Richard Dawkins has written, "Darwin made it possible to be an intellectually fulfilled atheist."

However, natural theology is making a comeback. There are features of the natural world, on both the macroscopic level of the universe as a whole and on the microscopic level of DNA, as well as on the intermediate level of the earth itself, that have again raised the issue of nature's "fine-tuning" for life. In a number of cases, if certain figures in chemistry and physics were even slightly different, there would be no life, no planets, no stars and, essentially, no universe.

"A common sense interpretation of the facts," the late British physicist Sir Fred Hoyle (d. 2001) remarked, "suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question." Hoyle was an atheist, and he wasn't particularly happy with any of this.

"As we look out into the Universe and identify the many accidents of physics and astronomy that have worked together to our benefit," observed Princeton physicist Freeman Dyson, "it almost seems as if the Universe must in some sense have known that we were coming."

Among the leading figures in the rebirth of natural theology is an Irishman named Alister McGrath. An atheist when he began his studies at Oxford University, he was a convinced Christian by the time he earned his doctorate there in molecular biophysics. Going on to receive another Oxford doctoral degree — this time in theology — he's become one of the most important thinkers, and certainly one of the most prolific writers, in English-speaking Christendom.

McGrath's newer form of natural theology is, in a sense, somewhat less ambitious than the old version. It doesn't claim to "prove" the existence of God. Unlike some proponents of "intelligent design," it typically doesn't even speak of probabilities. Rather, it seeks to demonstrate not only that what we're learning about nature is consistent with a Christian view of the universe, but that Christianity explains apparent "fine-tuning" better than other worldviews, such as secular materialism.

Daniel C. Peterson is a professor of Islamic studies and Arabic at BYU, where he also serves as editor in chief of the Middle Eastern Texts Initiative. He is the founder of, the general editor of "Interpreter: A Journal of Mormon Scripture" online at and he blogs daily at