Many Christians I’ve interacted with online or in person over the years have expressed immense skepticism over the question of extraterrestrial intelligence (ETI). Usually the subject becomes conflated with unidentified flying objects (UFOs), and dismissed as demonic. UFOs themselves are an often related topic of discussion to ETI, but not one inherently related by any means. If I had to guess why many Christians today are skeptical of ETI, I would pin it down to several reasons—the foremost of these being (1) a presumed incompatibility between the Christian worldview and the existence of other rational lifeforms, (2) ignorance of the long history of ETI debate in Christian theology and philosophy, and (3) narrow-minded biblicism (‘If it’s not in the Bible, it doesn’t exist’). Of course, not everyone fits into all of these categories, and there are many Christians, Catholic and Eastern Orthodox, who are certainly not ‘narrow-minded biblicists’ by any stretch of the term, yet reject the existence of ETI (a famous example is Fr. Seraphim Rose in his Orthodoxy and the Religion of the Future, where he argues that aliens / UFOs are demonic signs of the times).
The first point I mentioned is the most prominent, though in connection with the second point, it is interesting to see how Christians historically have not really seemed to detect much of a conflict between the existence of ETI and the veracity of the Christian claims.
To backtrack a bit, the ETI debate is closely connected with the plurality of worlds debate. It is important to note that in these early debates, a ‘world’ meant less of a single rocky planet like our earth, but a whole cosmos or universe (Thigpen 20). The idea of a plurality of such worlds first seems to emerge in the thought of the Greek atomists such as Leucippus (fl. 5th century BC), Democritus (c. 460 - c. 370 BC) and Epicurus (341–270 BC). Thinkers as this posited the existence of an infinity of other worlds. All that existed was atoms and void, atoms in the infinity of space would by sheer chance form another world like this eventually, so the reasoning went. A good example of the natural entailment of ETI from the pluralist doctrine is represented by the Roman atomist Lucretius (c. 99 - c. 55 BC) in his poem On the Nature of Things:
[I]t is in the highest degree unlikely that this earth and sky is the only one to have been created and that all those particles of matter outside are accomplishing nothing. This follows from the fact that our world has been made by nature through the spontaneous and casual collision and the multifarious, accidental and random and purposeless congregation and coalescence of atoms whose suddenly formed combinations could serve on each occasion as the starting point of substantial fabrics - earth and sea and sky and the races of living creatures […] You are bound therefore to acknowledge that in other regions there are other earths and various tribes of men and breeds of beasts” (Crowe 6-7)
The intellectual counterpart to the atomist school was represented by figures such as Plato (c. 427 - 348 BC) and Aristotle (384 - 322 BC), both of whom posited a single world, a geocentric universe. With Aristotle in particular, his theory of physics rendered a plurality of worlds impossible. Earth moves downward beneath our feet. Any earth ‘up there’ would be naturally drawn down to its natural place within the cosmos, thus rendering another world impossible and contrary to the laws of physics as Aristotle understood them. The Geocentric / singular world hypothesis would be adopted by Christian writers and figures almost unanimously, with the only dissenter being Origen of Alexandria (c. 185 - c. 253 AD), who himself did not argue for the plurality of worlds in the atomist sense, but for a plurality of temporally successive worlds one after another. Christian thinkers such as St. Hippolytus of Rome (c. 170 AD - c. 235 AD) and St. Philastrius of Brescia (died c. 379 AD), in fact, even labeled the plurality of worlds as ‘heretical’, with the latter saying it was contrary to Scripture (Thigpen 28). The oneness of the cosmos would remain the predominant and acceptable view of centuries to come. In the intervening centuries, between the days of the early Church and the Renaissance, the debate seems to surface in one form or another only occasionally. One tantalizing example is in a surviving letter from Pope St. Zachary (d. 752 AD) to St. Boniface, archbishop of Mainz in reference to a certain Vergilius:
"It will have become clear that he professes there exists another world, and other men under the earth, or the sun and the moon, he, when counsel has been taken, is to be ejected from the Church, and deprived of [priestly] honors” (Thigpen 340)
There is no proof this action was ever carried through, and the exact meaning of this has been disputed - as Thigpen asks, was Pope St. Zachary referring to the existence of multiple planets within a single universe, or the idea of multiple universes? Given his context in time, it seems like the latter is the more likely. And what could be meant by 'other men'? Does it refer to Homo Sapiens descended from Adam alone, or rational beings in general? Taken in their plain sense, it seems most likely that Pope St. Zachary was referring to other humans not descended from Adam.
With the re-discovery of Aristotle in the West, Christian thinkers such as St. Thomas Aquinas (c. 1225 - 1274 AD) utilized his insights to defend and systematize Christian thought within a coherent and rational framework. Aquinas himself believed that there was only a single world, defending it via Scripture, and via the argument that the unity and government of God result in a unitary and organized cosmos.
The ETI debate begins to slowly pick up steam in the late 13th century. In 1277, the bishop of Paris Étienne Tempier condemned various propositions relating to Aristotelian philosophy, threatening those who refused to recant with excommunication. One of the condemned propositions was the idea that God could not create multiple worlds. In the following century we see many figures who come out and begin to debate this notion, among them Nicole Oresme (1325-1382 AD), who argues in various ways for why the plurality of worlds is not incomprehensible, though he himself ultimately believes there truly is only a singular world. If, however, such worlds did exist, Oresme seems to assume they would indeed be inhabited:
“[I]f several worlds existed, no one of them would be outside Him nor outside His power; but surely other intelligences would exist in one world and others in the other world, as already stated.” (Crowe, 26)
Authors such as Michael J. Crowe put the responsibility for the notion of extraterrestrials moving from obscure fringe circles to respectable, mainstream Europe thought at the feet of Nicholaus Copernicus (1473 –1543 AD), who formulated a scientific theory of heliocentrism. Though his writings leave no evidence as to his opinion on ETI, it is crucial to the development of the speculation in the Christian world. Crowe says it best:
“The revolution launched by Copernicus resulted from his removing the Earth from the center of the universe, setting it spinning on its axis, and revolving around the Sun. This action transformed the Earth into a planet, which in turn suggested that the planets may be earths, in other words, that they may be inhabited. In the longer run, it turned stars into suns, which some suggested themselves may be surrounded by inhabited planets.” (Crowe 36-37)
Also the 15th century, men come along who positively affirm the actual reality of an infinity of worlds from a Christian perspective, including very prominent figures such as Nicholas of Cusa (1401-1464 AD), a German philosopher, papal legate and cardinal in the Catholic Church. Though dying before Nicolaus Copernicus was even born, Nicholas anticipates him in some senses, writing in various places scattered through his treatises how the earth is a star like other stars, denied geocentrism, the immobility of the earth, and explained this difference between the appearance of immobility and reality by relative motion. Nicholas also wrote of ETI briefly in his work On Learned Ignorance:
“Nor can this be known according to place, namely, that this place of the world is the habitation of humans, animals, and plants that are in degree less noble than in the region of the inhabitants of the sun and of the other stars. God is the center and circumference of all the regions of the stars and from God proceed the natures of different nobility that inhabit each region, lest so many celestial and stellar places be empty and only the earth, perhaps from among the lesser things, be inhabited. Yet it does not seem possible that according to the intellectual nature that exists here on earth and in its regions, even if inhabitants of another king should exist on other stars. The human being, in fact, desires no other nature but only to be perfect in the human being’s own nature” (Nicholas of Cusa 163)
Unfortunately, however, I have not been able to find anything that suggests Nicholas made any christological speculations in regards to the possibility of ETI in the celestial and stellar regions. Contemporary with Nicholas of Cusa, however, one example of this tendency was a certain Franciscan named William Vorilong (d. 1464). Vorilong, who along with arguing that that a plurality of worlds would actually be *more* perfect than a singular world (contrary to Aquinas), he also dwells on the question of ETI and takes the speculation in an interesting new direction:
“If it be inquired whether men exist on that world, and whether they have sinned as Adam sinned, I answer no, for they would not exist in sin and did not spring from Adam. But it is shown that they would exist from the virtue of God, transported into that world, as Enoch and Elias in the earthly paradise. As to the question whether Christ by dying on this earth could redeem the inhabitants of another world, I answer that he is able to do this even if the worlds were infinite, but it would not be fitting for Him to go into another world that he must die again” (Crowe, 27)
Not only does Vorilong raise the question of their nature—whether it is sinful or not—but whether Christ would have to go to that world and die there too. A whole Christological dimension opens up. Vorilong goes with the perhaps more theologically palatable conclusion that Christ’s atoning death was all-sufficient, even for ETI outside of our world. This position would also be taken by the Dominican Tommaso Campanella (1568 - 1639 AD) in the 17th century (Thigpen 64-65). This is one solution, the other is implied directly in the passage—multiple incarnations. Vorilong was not the only one to mention the theologically possibility of multiple incarnations. The Protestant reformer and associate with Martin Luther, Philip Melanchthon, gives witness to the fact that this view was floating around in some circles in his own day, which he criticizes on Scriptural grounds:
“[T]he Son of God is One; our master Jesus Christ was born, died, and resurrected in this world. Nor does he manifest Himself elsewhere, nor elsewhere has He died or resurrected. Therefore it must not be imagined that Christ died and was resurrected more often, nor must it be thought that in any other world without the knowledge of of the Son of God, that men would be restored to eternal life.” (Crowe 37)
The notion of multiple incarnations would be floated occasionally over the course of the following centuries. by men such as William Haye (1695 - 1755 AD), and the author of work known as Traité de l’infini créé (Treatise on created infinity, 1769), and more modern figures such as E. L. Mascall (1905-1993 AD) and Kenneth Delano (d. 2017 AD). All of these figures raise the possibility of multiple incarnations of God. This is the area where the implications start to feel a bit…strange. The Bible says that the Word took on flesh and dwelt among us…but was it only us? Or besides becoming man, did the Word also assume the flesh of a myriad of rational extraterrestrial beings out there in the vast cosmos? Obviously we have no idea, but it is not impossible—nothing in the concept itself seems to be contradictory or inherently implausible.
Thomas Paine, the author of the famous pamphlet Common Sense was of the opinion that the existence of ETI would be destructive to the Christian faith, a position which a not insignificant number of people implicitly or explicitly hold to today, whether they are of religious persuasion or, like Paine, of a more anti-Christian perspective. He wrote in his Age of Reason:
“From whence, then, could arise the solitary and strange conceit that the Almighty, who had millions of worlds equally dependent on his protection, should quit the care of all the rest, and come to die in our world, because, they say, one man and one woman had eaten an apple? And, on the other hand, are we to suppose that every world in the boundless creation had an Eve, an apple, a serpent, and a redeemer? In this case, the person who is irreverently called the Son of God, and sometimes God himself, would have nothing else to do than to travel from world to world, in an endless succession of deaths, with scarcely a momentary interval of life.”
And indeed, in Paine’s view:
“Though it is not a direct article of the Christian system, that this world that we inhabit is the whole of the habitable creation, yet it is so worked up therewith, from what is called the Mosaic account of the Creation, the story of Eve and the apple, and the counterpart of that story, the death of the Son of God, that to believe otherwise, that is, to believe that God created a plurality of worlds, at least as numerous as what we call stars, renders the Christian system of faith at once little and ridiculous, and scatters it in the mind like feathers in the air. The two beliefs cannot be held together in the same mind, and he who thinks that he believes both, has thought but little of either.”
Thus, contrary to numerous eminent Renaissance era Christian theologians and philosophers, Paine is of the opinion that Christianity is immeasurably damaged by the plurality of worlds, and is indeed rendered silly and absurd, especially by the idea of multiple incarnations, deaths and resurrections. Jumping back in time, I can also understand why one such as Vorilong would balk at it though. Just think of questions that are immediately raised by this hypothesis—is it permissible to worship multiple incarnations of Christ, given that they are one and the same divine Logos? One would think ‘yes’, but it immediately starts to make Christianity look a lot less familiar and more bizarre. Could one worship alien Jesus as a sort of Christianized ‘iṣṭa-devatā’? Honestly, it really does seem to make Christianity increasingly quasi-Hindu, and I don’t mean this in any pejorative sense per se. Just look at the Vaishnava tradition, with a plurality of divine avatars, and how Krishna states in the Bhagavad Gita that whenever there is a decline in dharma and a rise of adharma, he descends into the world for the sake of his devotees, age after age (Bhagavad Gita 4:8-9). Does not Christ do this on a cosmic scale in the multi-incarnational hypothesis? While there remains differences, the tenor changes, certainly.
Or in connection with these speculations, does Jesus thus have a plurality of mothers? What does this mean for Catholics who venerate the virgin Mary as exalted Queen of Heaven? Is Mary merely one among many? Still a special woman certainly as Mother of God, but does she assort with a whole contingent of extraterrestrial heavenly Queens? Or did the Word redeem different species in different manners? How did He die? Did He die? Are there planets not in sin where He incarnated and dwelt among them out of pure love alone? Does the prohibition of affirming polygenism in Pope Pius XII’s Humani Generis have any implications for rational extraterrestrial life? Or does it apply, as the document says, only “on this earth”? The speculations are endless, and fascinating to ponder.
Ultimately though, we merely have to suspend judgment at the present moment. Is all or some of this true? We don’t know. Or maybe people such as William Vorilong and Tomasso Campanella are indeed correct, and Christ’s death here on earth was sufficient and efficacious for all rational beings throughout the cosmos. But how many trillions of beings on infinite worlds then must hunger for the Gospel and live in darkness, living for millennia without knowing about Jesus Christ. It is the whole problem of the Native American faced by the Dominican theologians at the University of Salamanca all over again. Due to such smaller scale theorizing, however, we already possess all the tools needed to explain how ETI could be saved apart from explicit faith in Christ and reception of the sacraments. Neither position can be refuted outright. God is often operating on a far grander scale than we comprehend. We often make God small, but continually He has shown Himself more and more grand beyond our wildest imaginations. Perhaps Giordano Bruno (1548-1600 AD) is correct:
“Thus is the excellence of God magnified and the greatness of his kingdom made manifest: he is glorified not in one, but in countless suns; not in a single earth, a single world, but in a thousand thousand, I say in an infinity of worlds” (Crowe 44)
If ETI do indeed exist, the Christian tradition has already for centuries been preparing for a way to handle the existence of such beings from their experience with the discovery of the New World, and from of course an active and lively participation in the debate over the plurality of worlds and whether they could be inhabited, and in what ways Christ could or would operate to bring them to salvation. Thus, I believe that Christians have no reason to fear any future discoveries or contact—there is no reason to inherently dismiss them as demonic beings. Philosophers, theologians, cardinals, friars, popes and saints and many others have long seen no fundamental contradiction between the Christian worldview and the existence of extraterrestrial intelligence.
St. Padre Pio
“[W]e Earthlings are nothing, too. The Lord certainly did not limit His glory to this small Earth. On other planets other beings exist who did not sin and fall as we did.
St. John Paul II (when asked by a young boy if there were any aliens)
“They are children of God as we are”
John 10:16
“And I have other sheep that are not of this fold. I must bring them also, and they will listen to my voice. So there will be one flock, one shepherd.”
References
Bhagavad-gita As It Is, translated with commentary by A. C. Bhaktivedanta Swami Prabhupada
Did Padre Pio Affirm the Existence of Aliens? ( https://www.stcatherinercc.org/single-post/2020/09/23/Did-Padre-Pio-Affirm-the-Existence-of-Aliens )
Extraterrestrial Intelligence and the Catholic Faith: Are We Alone in the Universe with God and the Angels?, by Paul Thigpen
Extraterrestrial Life Debate, Antiquity to 1915: A Source Book, edited with commentary by Michael J. Crowe
Humani Generis, by Pope Pius XII
Nicholas of Cusa: Selected Spiritual Writings, by Nicholas of Cusa, translated by H. Lawrence Bond
Orthodoxy and the Religion of the Future, by Fr. Seraphim Rose
Salvation Outside the Church: Tracing the History of the Catholic Response by Francis A. Sullivan, SJ
The Age of Reason, by Thomas Paine