The Teleological Proof. A Posteriori Argument: A argument in which a key premise can only be known through experience of the actual world. Principle of Sufficient Reason (PSR): For every positive fact, whatsoever, there is a sufficient reason, known or unknown, explaining why it is.
The Teleological Proof • A Posteriori Argument: A argument in which a key premise can only be known through experience of the actual world. • Principle of Sufficient Reason (PSR): For every positive fact, whatsoever, there is a sufficient reason, known or unknown, explaining why it is. • Teleological System: A collection of parts that, under the proper conditions, work together to achieve some telos (goal or purpose).
The Teleological Proof • There are teleological systems in nature, e.g. the human eye, the human circulatory system, the human nervous system. (Premise) • The teleological systems in nature are either the product of purely natural, non-intelligent forces or the product of some form of supernatural, creative intelligence. (Premise)
Purely natural, non-intelligent forces are not a sufficient explanation for the teleological systems in nature. (Premise) • Therefore, a supernatural, creative intelligence exists. (from 2 & 3 and PSR) Discussion of the Teleological Proof • The Argument is valid. The question is whether it is sound, i.e. whether all its premises are actually true.
All parties to the discussion concede (1.) & (2.). The dispute is over (3.). • Criticisms of (3.) • David Hume’s alleged weak analogy. • David Hume claimed that (3.) is based upon a weak analogy between natural and non-natural teleological systems, e.g. a watch. • Since they are non-natural, there is no other possible explanation for non-natural teleological systems than a creative intelligence.
Since they are natural, however, one must allow for at least the possibility that natural teleological systems might have been naturally produced. • St. Thomas Aquinas anticipated Hume’s objection and responded to it • “We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to
“obtain the best result . . . . Now whatever lacks intelligence 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. Therefore, some intelligent being exists by whom all natural things are directed to their end . . . .” St. Thomas Aquinas, Summa Theological, I, 2, iii
Aquinas’ point is that anything that lacks intelligence in itself cannot pursue a goal unless it is directed toward that goal by something that has intelligence, e.g. the arrow is directed by the archer. • Whether they are natural or non-natural, all teleological systems lack intelligence in themselves. • Thus, they must be directed toward their goals by something that has intelligence.
A challenge to Aquinas – Darwinian evolution. • Contrary to what Aquinas claims, Darwinian evolution seems to account sufficiently for natural teleological systems, without appealing to a supernatural, creative intelligence. • Teleological systems evolved slowly over millions of years as a result of random genetic mutations that were “naturally selected for” because, given the environment, they provided greater survivability.
In the last twenty years or so, Darwinian evolution has come under attack by scientists. • In November of 2001 a full page ad, appearing in several national publications and signed by over 100 scientists of various sorts, stated: • “[We are] skeptical of the claims for the ability of random mutation and natural selection to account for the complexity of life.”
One of the scientists who signed the ad, Michael Behe (Professor of Biochemistry at Lehigh University), published Darwin’s Black Box in 1996. • In this book, Behe argues that natural teleological systems, e.g. the human eye, are irreducibly complex. • This means that, if all the parts of a teleological system are not present, it won’t work 50% as well, or 25% as well, or even 10% as well.
If all the parts of a teleological system are not in place, the system won’t work AT ALL. • Thus, concludes Behe, it is inherently impossible for natural teleological systems to have evolved naturally over time. • Another challenge to Darwinian evolution is the movie 2001: A Space Odyssey.
As you watch this movie, ask yourself: Does the filmmaker, Stanley Kubrick, give an argument for the insufficiency of Darwinian evolution as an explanation for human existence, or is his movie merely a testament of his faith? • Kubrick’s point is that evolution has “petered out.” The only way humans can advance to the next stage is if they get help from “the gods.”
If humans need “the gods’” help for the next great leap, they probably needed it for the first great leap. • But, in Kubrick’s vision, “the gods” remain utterly mysterious. • While, assuming it’s sound, the teleological proof provides support for theism, it cannot prove, in His totality, the God of traditional theism.