A teleological argument (or an argument from design) is an argument for the existence of God based on evidence of design in nature. Although there are variations, the basic argument goes something like this:

  • Premise 1: X was intelligently designed.
  • Premise 2: X was not designed by humans.
  • Premise 3: The only conceivable beings capable of intelligent design are humans (who exist) and God (who may or may not exist).
  • From (3): The only conceivable beings capable of designing X in particular are humans (who exist) and God (who may or may not exist).
  • Recall (2): that X was not designed by humans.
  • If God doesn't exist, then X was also not designed by God.
  • Thus if God doesn't exist, then none of the conceivable beings capable of designing X designed X, in which case X was not designed at all.
  • Since God not existing therefore results in a contradiction of (1), God must exist.

X usually stands either for a given animal species or for a particular organ (e.g., the eye) or capability (e.g., language) of a given species. It can also stand for the fundamental constants of the universe, based on the anthropic principle that these constants seem specially tuned to allow intelligent life to evolve.

This argument is very popular today in the United States, probably because it seems to be the most "scientific" argument for the existence of God. It is at the core of the theory of Intelligent Design.

Although the second premise is widely accepted, the third premise, and especially the first premise, are disputed.

Table of contents
1 First premise
2 Third premise
3 Other counter-arguments
4 History
5 References and further reading

First premise

The first premise assumes that one can infer the existence of intelligent design, merely from examining the designed object. This belief forms the basis of the Search for Extra-Terrestrial Intelligence, which attempts to determine whether electromagnetic radiation is the result of a natural process, or the intelligent design of an alien race.

Simplistic forms of the teleological argument assume that because life is complex, therefore it must have been designed. Some characterise this approach as an argument from ignorance.

Stronger forms rely on the concepts such as irreducible complexity, which was proposed by Michael Behe.

With few exceptions, all professional biologists support the theory of biological evolution by means of natural selection. They reject the first premise, arguing that evolution is not only an alternative explanation for the existence of X but a better explanation. Thus they tend to view the teleological argument as a poor argument for the existence of a god.

Third premise

Some argue that, even if the argument correctly implies the existence of a non-human artificer (i.e., if the first and second premise are accepted)), that artificer might not be God, as God is commonly understood. Why couldn't it have been alien civilization from another world?

Other counter-arguments

Although the third premise appears to be the most embattled portion of the argument, refutations have also been tried along other grounds. One approach is a proof by contradiction:

  • Premise 1: The teleological argument is valid (assumption for reductio)
  • Therefore: An intelligent designer exists.
  • Premise 2: The teleological argument applies to the intelligent designer, for the designer must be at least as complex and purposeful as the designed object
  • Therefore: An intelligent designer of the intelligent designer exists.
  • Similarly: An infinite chain of intelligent designers exists.
  • Premise 3: An infinite chain of intelligent designers does not exist, for this is absurd.
  • Conclusion: one of the three premises is false.

See also: first cause

History

Cicero made one of the earliest teleological arguments, by means of a timepiece:

When you see a sundial or a water-clock, you see that it tells the time by design and not by chance. How then can you imagine that the universe as a whole is devoid of purpose and intelligence, when it embraces everything, including these artifacts themselves and their artificers? (Gjertsen 1989, p. 199, quoted by Dennett 1995, p. 29)

David Hume presented arguments both for and against the teleological argument in his Dialogues Concerning Natural Religion. The character Philo, summarizing the teleological argument, uses an example of a watch. Philo is not satisfied with the teleological argument, however, and attempts a number of interesting refutations, including one that arguably foreshadows Darwin's theory. In the end, however, Hume has Philo agree that the teleological argument is valid. (Dennett 1995, p. 29) Daniel Dennett (ibid.) claims that, although Hume was ultimately dissatisfied with the teleological argument, his cultural context prevented him from taking any of the alternatives seriously.

The most famous proponent of the teleological argument is William Paley (1743-1805), who, also, framed the argument with reference to a watch.

References and further reading

See also: Design