Recently there has been much speculation in the popular press — and also in more scientific circles — about the possible existence of extraterrestrial in­telligence (ETI). It may thus be of some interest to look a bit more closely at the background and implications of the current debate.

History of Belief in ETI⤒🔗

Belief in ETI has a very long history. ¹ It can be traced back to at least the Greek philosopher Democritus (ca. 460-370 BC), who believed that there were an infinite number of worlds, each with a central, inhabited earth. He was also convinced that the Moon was inhabited.

However, belief in ETI was not widespread in ancient times; nor, for that matter, in the medieval world, whose finite, geocentric cosmology had no place for other populated planets. The big boost for ETI came with the advent of the Copernican revolution in the 16th century. With the demotion of the Earth to just another planet, there was no longer any reason to believe that it was unique in either composition or function. Thus the famous astronomer, Johannes Kepler (1571-1630), thought that the Sun, the planets, and particularly the Moon, were also inhabited.

By the end of the 18th century belief in ETI was nearly unanimous in the worldwide scientific community. The demon­stration of the absence of a lunar atmosphere had by this time ruled out the posibility of lunar creatures. But this merely trans­ported the presumed presence of ETI to other celestial objects.

The prime candidate now became the planet Mars. Interest in ETI was further increased by the claim of Percival Lowell, in the early 20th century, that he had observed canals on Mars, although such claims were soon discounted by most profession­al astronomers. Nevertheless, the belief that there was, at least, some form of life on Mars was not laid to rest until the landing of the Viking spacecraft on Mars in 1976.

The Scientific Evidence for ETI←⤒🔗

How strong is the scientific case for ETI? Estimates vary considerably and, during the last few years, there has been a lively debate between scientists who believe that the existence of ETI is widespread and those who feel that it is very rare, with man perhaps being unique.

One of the more prominent members of the optimistic camp is Carl Sagan, a well-known popularizer of astronomy. Sagan has been involved in using the huge radio telescope in Puerto Rico to search for signals from distant civilizations. Thus far such efforts have been entirely fruitless.

The optimists argue that many stars have planets; that a good fraction of these planets are suitable for life; that life in fact develops on a sizeable portion of such inhabitable planets; and, finally, that a significant number of these life-bearing planets produces intelligent civilizations. Even if the fraction in each case is on the small side (say 1 out of 100), the huge number of stars in our galaxy alone (estimated at about 300 billion) would still leave us with a potential of approximately 3000 intelligent civilizations in our galaxy alone.

On the other hand, the pessimists point out that all of the above factors are highly uncertain. From time to time we may hear rumors in the press that other planetary systems have been discovered, but in actual fact observations have not yet pro­vided any clear, persuasive evidence for their existence. Further­more, no signs of life have yet been found beyond the Earth. (The absence of life on Mars was a heavy blow for proponents of ETI.) It is worth mentioning here that the most notable evolutionist biologists have considered the evolution of life from non-life to be immensely improbable and have therefore always been united against ETI. Recently, a scientist estimated the probability of life occurring by chance on an inhabitable planet, even under the most optimistic conditions, as less than 10ˉ³², that is, one out of hundred million trillion trillion.²

Hence even secular, evolutionary science is, in its present state, not favorably inclined towards ETI. Supporters of ETI claim, however, that our present grasp of the evolutionary mechanism is incomplete and that further developments will vindicate their belief that evolution is much more probable than is currently believed. After all, they contend, if intelligent life can evolve on such an insignificant planet as ours, why not elsewhere?

A further argument for the scarcity of ETI is the fact that our earth has, apparently, not been colonized by ETs. It has been asserted that if ETI were common in our galaxy, then at least one of the more advanced civilizations would have ex­plored and colonized the galaxy by now, just as we have spread out over the earth. Since we don't see ETs, and since there is no evidence that they have ever visited us, it follows that ETI must be rare ³ (very few astronomers believe that UFOs are ET visitors).

The above arguments are all based upon the premise that man, and life in general, has an evolutionary origin. How does the case for ETI look on the assumption of a direct creative origin of man and other forms of intelligence? In fact, before the advent of the evolution theory, most of the arguments in favor of ETI were formulated in creationistic terms. Thus it was asked, for example, why God should have created intel­ligent life on earth and not elsewhere.

In the 17th century the newly invented telescope revealed many hitherto invisible stars. Since these could hardly serve as light-bearers for man, their purpose was questioned. Many argued that they served as suns for other intelligent beings, placed there by God. Furthermore, it was contended that, since two universes are better than one, and since the Creator always chose the best, there should be an infinite number of inhabited worlds. Anything less was considered unworthy of an infinite Creator.

It is evident that creationist arguments for ETI are strongly dependent upon our speculations regarding the nature of God and His relation to His creation. Such questions can ultimately be resolved only to the extent that these matters are revealed to us by God through His Word.

Note, by the way, that from the creationist perspective the above-mentioned colonization objection to ETI is no longer valid. For if the universe is very young, then ETs may not have had enough time to develop and apply their exploration potential.

Theological Objections to ETI←⤒🔗

Throughout the ages several theological criticisms have been leveled against the belief in ETI. One major argument was based on the creation account of Genesis 1. There we read that man alone was created in the image of God, and man alone was appointed to have dominion over the creation. The crea­tion of the stars is merely a minor point, with their prime func­tion being to serve as lights and signs for man. It thus appeared that man participated in a unique one-to-one relationship with God.

Furthermore, if ETs do exist, why are they not mentioned in Scripture? The Lutheran theologian, Melanchton (1497-1560), noted that after God had created the earth, sun, moon, and stars of our cosmos, He rested and created nothing more — least of all another cosmos. He also pointed out that nowhere does Scripture mention the creation of man, or other life, out­side of the earth.

The foremost theological objection to ETI, however, has always been centered on the uniqueness of Christ's incarnation. It dates back to at least Church Father Augustine (354-430). Augustine was concerned with opposing the cyclical view of history (i.e. the notion that history repeats itself in an endless cycle) current in his day. On the basis of such Biblical texts as "Christ died once for all our sins" (1 Peter 3:18) and "in rising from the dead He is never to die again" (Romans 6:9), he argued that the historical process creation, fall, and redemp­tion could occur but once.⁴

The argument was extended by Albertus Magnus (1206­-1280) to refute also the idea of a multitude of worlds in space, rather than time. The above-mentioned Melanchton emphat­ically rejected belief in ETI primarily because he affirmed that Christ could die only once and that man in other worlds could be saved only through knowledge of Christ.

The question of the uniqueness of Christ's sacrifice doesn't appear to bother most modern theologians who discuss ETI.⁵ Accepting the evolutionary origin of man, they feel that the earth's history could well be repeated elsewhere. Paul Tillich and Dean Inge, for example, both argue that the incarnation is likewise not unique and could occur also on other planets.

The cosmologist, E.A. Milne, resolved the paradox be­tween the uniqueness of Christ and the plurality of worlds by suggesting that knowledge of the incarnation could be trans­mitted to other planets via radio signals. Milne is criticized on this matter by the theologian, E.L. Mascall, who contends that salvation is not dependent upon our knowledge and that there­fore the fact of Christ's appearance need not be transmitted.

However, it is clear from Scripture that there is a necessary connection between Christ and Adam: that for Christ's sacrifice to be sufficient for man's salvation it is essential that He has a human nature (cf. Heidelberg Catechism, Q&A 16, and Scrip­ture references cited there). It seems to follow that this salva­tion does not extend to ETs, who are not descendants of Adam. Thus the uniqueness of Christ's incarnation implies the unique­ness also of man as the only creature to be saved from the con­sequences of his sinfulness.

Accordingly, Thomas Chalmers, a famous Scottish theolo­gian of the early 19th century, who didn't question the existence of ETI, argued that man may be the only intelligent species in the universe that fell from grace. A similar theme is echoed by C.S. Lewis in his well-known science fiction trilogy. A less happy alternative is the thought that other species have also fallen but that only ours is to be redeemed.

Motivation for Belief in ETI←⤒🔗

Given the lack of scientific evidence for ETI, it is apparent that belief in ETI is based on other, more philosophical factors. The American physicist, Frank Tipler, who believes that we are unique in the universe, sees a similarity between belief in ETI and belief in UFOs:

In fact, I suspect the psychological motivation of both beliefs to be the same, namely, the expectation that we are going to be saved from ourselves by some miraculous interstellar in­tervention...⁶

He supports this conclusion by citations from numerous prominent supporters of ETI. Typical is the following state­ment from Carl Sagan:

The translation of a radio message from the depths of space ... holds the greatest promise of both practical and philosoph­ical benefits. In particular, it is possible that among the first contents of such a message may be detailed descriptions for the avoidance of technological disaster, for a passage through adolescence to maturity… It is difficult to think of another enterprise within our capacity and at a relatively modest cost that holds so much promise for the future of humanity.⁷

In a similar vein, the Harvard astrophysicist, A.G.W. Cameron, writes:

If we can ... communicate with some of these (advanced ET) societies, then we can expect to obtain an enormous enrich­ment of all phases of our sciences and arts. Perhaps we shall also receive valuable lessons in the techniques of stable world government.⁸

It is ironic that secular man, finally confessing his deficien­cies, now searches the heavens for his salvation. For although he is looking in the right direction, he looks in vain unless the God, whom he denies, reveals Himself. And He has done so, in His Word.

No Solid Scientific Evidence←⤒🔗

In conclusion, we note again that there is virtually no solid scientific evidence in support of belief in ETI. Indeed, the pres­ent state of even the secular, evolutionary theory renders the existence of ETI as being extremely improbable.

Theological considerations, as we have seen, weigh very heavily against the presence of ETI (other than, of course, spiritual beings such as angels and demons), but not conclusive­ly so. But of one thing we are sure: According to the Scrip­tures the earth is very certainly in the centre of God's attention.