What is likely to be our reaction if we did receive an unambiguous signal that there existed ETI somewhere else in the universe?

The reaction would be hard to predict because it is not a topic that is not publicly discussed much. This is a bit surprising because it is not such a stretch to think that we could wake up one morning to find out that we have received some signal from an alien civilization. I suspect that the reason why we don’t speculate on this question is that any such occurrence might be extremely difficult for most people to absorb into their existing worldviews, so they avoid thinking about it.

Take religious believers. If there is life elsewhere, what does that do to the common idea that humans somehow have a special relationship to god? For Christians, if Jesus died on Earth as a redemptive act for all humankind, did a similar event take place with these other alien civilizations? Would Jews still be able to see themselves as some god’s chosen people? Why did the angel Gabriel not reveal this information of ETI to Mohammed during one of their chats?

I suspect that religious apologists would quickly get to work to come up with new doctrines that would keep the faithful loyal. After all, very similar theological challenges have been encountered before although they are not remembered now. After Copernicus’s ideas about a heliocentric solar system sank in and it became clear that the Earth was merely one of several planets, theologians worried that this meant that other planets could also have inhabitants and this would cause problems for religious doctrines.

As Thomas Kuhn pointed out in book The Copernican Revolution:

When it was taken seriously, Copernicus’ proposal raised many gigantic problems for the believing Christian. If, for example, the earth were merely one of six planets, how were the stories of the Fall and of the Salvation, with their immense bearing on Christian life, to be preserved? If there were other bodies essentially like the earth, God’s goodness would surely necessitate that they, too, be inhabited. But if there were men on other planets, how could they be descendents of Adam and Eve, and how could they have inherited the original sin, which explains man’s otherwise incomprehensible travail on an earth made for him by a good and omnipotent deity? Again, how could men on other planets know of the Savior who opened to them the possibility of eternal life? … Worst of all, if the universe is infinite, as many of the later Copernicans thought, where can God’s Throne be located? In an infinite universe, how is man to find God or God man? (p. 193)

The Copernican model, once its implications were fully appreciated by the theologians, thus raised some serious problems. Fortunately for the theologians, no life was found on the other planets so they did not have to deal with the implications of original sin, of Adam and Eve as being created in god’s image, of the fall from grace, of Jesus as savior, and so on.

Similar problems were encountered with the early exploration of the world. Before the arrival of Europeans in the New World, for example, St. Augustine went so far as to argue that there could not be human beings already there because the Bible said that all humans were descended from Adam and Eve, and since there was no way that their descendants could have got to the other side of the Earth (what they called the Antipodes), that meant there could not be any humans there. Such was the typical approach of one of the Catholic Church’s great thinkers: start with a doctrinal belief and then use that to predict what the data should reveal. In science, we may start with a paradigmatic model to make a prediction but we never depend upon any revelation or a special text.

Of course, Augustine was wrong. But as always, the theologians managed to absorb the discovery that the New World was indeed inhabited and devise ways to incorporate these new and awkward scientific facts in ways to keep the faithful loyal.

Next: The potential benefit of receiving signals an ETI.

POST SCRIPT: But seriously,…

Our wise pundits start to discuss the really important issues.