The argument from design in Christianity
From Aquinas's Fifth Way to Paley's watchmaker to modern Intelligent Design, Christian apologetics has continually rebuilt the design argument as natural theology has shifted under it — and as natural science has steadily explained more of what once needed a designer.
The argument from design is the Christian tradition's most popular and most contested piece of natural theology. Thomas Aquinas's Fifth Way (Summa Theologica, 1265–1274) gave it scholastic form: things lacking intelligence act for an end, and what acts for an end without knowing it must be directed by a knowing being, which we call God. The argument was defended in this teleological mode by Catholic and Protestant theologians for five centuries, but its most famous statement came from William Paley in Natural Theology (1802): the man who finds a watch on a heath rightly infers a watchmaker, and the apparent design in nature warrants an analogous inference to a divine designer.
Paley's argument was the dominant case for theism in nineteenth-century Anglophone Christianity until Darwin's Origin of Species (1859) supplied a non-design explanation for biological complexity. Conservative theology absorbed the blow in two main ways. Theistic evolutionists (B.B. Warfield, Pope John Paul II in Humani Generis and 1996) accepted the science and located divine action in the broader fact of an ordered, life-permitting cosmos rather than in particular biological structures. The Intelligent Design movement, organized in the 1990s around the Discovery Institute and figures like William Dembski and Michael Behe, instead pressed a narrower argument for irreducibly complex biological systems — a strategy that has had limited success in mainstream biology and was decisively rejected as science in Kitzmiller v. Dover (2005).
The most resilient Christian design argument today is fine-tuning rather than biological design, championed by philosophers like Robin Collins and Richard Swinburne. Critics from Hume's Dialogues Concerning Natural Religion onward have argued that the design inference is circular (it presupposes the standards of intelligent agency it claims to discover) and explanatorily empty ("who designed the designer?"). The argument's modern Christian defenders concede that it does not by itself establish the God of any particular creed — but argue that, paired with other evidence, it gives reason to take theism seriously as a hypothesis.
- Thomas Aquinas— The Fifth Way (Summa Theologica)
- William Paley— Natural Theology (1802); the watchmaker analogy
- B.B. Warfield— Reformed reconciliation with Darwinian biology
- Michael Behe— Irreducible complexity (Darwin's Black Box, 1996)
- William Dembski— Specified complexity and design inference
- Robin Collins— Fine-tuning argument from physical constants
“The heavens declare the glory of God; and the firmament sheweth his handywork.”
“In crossing a heath, suppose I pitched my foot against a stone, and were asked how the stone came to be there... but suppose I had found a watch upon the ground, and it should be inquired how the watch happened to be in that place; I should hardly think of the answer which I had before given.”
“Whatever lacks knowledge cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer.”