The possibility of the discovery of intelligent extra‐terrestrial life raises significant questions about the role that extraterrestrials would play in the universal plan of God. Particularly in regard to the theology of original sin and redemption, the question of fallen extraterrestrials who do not share the human nature assumed by Christ is an interesting and important one for contemporary theologians. By exploring this question, not only can contemporary theology gain insights into this (currently) hypothetical case, but because this investigation touches on key aspects of Christian anthropology and soteriology, it has the potential to clarify and improve our current understanding of these central aspects of Christianity, particularly the role that human nature plays in redemption. This paper will attempt an investigation of hypothetical intelligent extraterrestrial life from the perspective of the philosophy and theology of St. Thomas Aquinas. Section I will feature an overview of St. Thomas's relevant philosophy of human nature and its application to a hypothetical intelligent extraterrestrial species, concluding that (although it has an immortal and rational soul) the species does not share human nature. Section II will, with special attention to St. Thomas's De malo, treat some possibilities regarding the need for salvation (or lack thereof) in our hypothetical species. Section III will outline relevant aspects of Thomistic soteriology, especially the reasons behind the Incarnation and the role of human nature in Redemption. Section IV will feature a critique of representatives from the two major schools of scholarly thought on this issue, showing that they either disregard the necessity of a human nature for incorporation into the Mystical Body of Christ or deny the magnitude and singular importance of the Incarnation. Section V will sketch some possibilities for the soteriology of extraterrestrial life using the theology of St. Thomas Aquinas as a framework.
I
Crucial to further reflections on this issues is a philosophical one about the nature of intelligent alien species. While there is very little that that such an investigation as this can do without access to the biological aspects of such a species, perhaps we can bracket the particulars of that question for the philosophical and theological purposes of this paper. In order to apply Christian revelation to this new problem, there would need to be analysis of the nature of that extraterrestrial species. On the assumption that the species is recognizably rational, we may be able to proceed with our philosophical investigation to set the groundwork for the theological investigation.
Let us suppose, for the purposes of our minimal necessary information, that we found a species of creatures that looked very much like mollusks on Earth (that is, they do not have the usual physical traits we associate with humanity), but were nonetheless intelligent. The minimum cognitive capabilities necessary to qualify for “intelligence” in the Thomistic perspective will be discussed below. With these two pieces of information, it may be possible to proceed with a sufficient Thomistic philosophical “cephalopodology”Footnote 1 for the question at hand.
A robust philosophy of nature is extremely helpful both to the understanding of the physical world and indispensable to Christian theology.Footnote 2 An important aspect of Thomistic anthropology is the hylomorphic doctrine that form and matter are co‐principles in the composite unity that constitutes the human being. The classical definition of the human being used by Aquinas is a “rational animal.” It would be tempting to use this definition in a broad way to include other species of rational animals and thus apply all of the teachings of the Christian tradition to extraterrestrials with almost no modification. This, however, is not consonant with the metaphysics of St. Thomas. The centrality of the philosophical concept of nature (or “essence”) to Christian dogma and St. Thomas's doctrine requires that we review some key aspects of Thomistic metaphysics before applying this concept to a hypothetical extraterrestrial species.
In Thomistic metaphysics, the terms “essence,” “quiddity,” and “nature” all denote the same aspect of being and have several important meanings that are applicable to the question at hand.Footnote 3 In chapter 1 of the small work De ente et essentia, St. Thomas outlines some fundamental aspects of the philosophy of nature. There he states that essence is a metaphysical principle which places a being into one of Aristotle's ten fundamental categories of being.Footnote 4 Essence also confers “quiddity” or “whatness” on real beings, making real beings definable.Footnote 5 Quiddity makes real beings the kind of beings that they are.Footnote 6 Based on the above structuring function of essence, the essence or nature of a thing makes that thing intelligible to intellectual creatures who can grasp the quiddity or nature of it.Footnote 7 Because an essence makes a thing what it is, and a being's powers and capacities flow from what it is, essence is the grounding of all of the powers and capacities of a being.Footnote 8 Finally, essence is a metaphysical principle that constitutes real beings and is that through which and in which they exist.Footnote 9
All material beings have a composite essence, made up of matter and form.Footnote 10 Matter and form are two co‐principles of composite unified being. They explain the potential of that being to exist or be structured in a certain way and the activation of that which has potential to exist or be structured in that way, respectively.Footnote 11 Since material beings are made up of matter, matter is a constituent of what they are and because they are structured and intelligible, metaphysical form is another constituent. For the purposes of this paper, it is crucial to note that neither form alone nor matter alone constitute the essence of a material being.Footnote 12 Because the essence of a thing must include all that is denoted in the definition of that thing, it must include both form and matter.Footnote 13 Therefore, the essence and definition of human beings must include both the specifically human form (which is the rational soul that is both the seat of the intellect and the substantial form of the human being) and specifically human matter.
It is here where the biological investigation of extraterrestrial species is crucial to our investigation. If an extraterrestrial species has matter that is radically different from human matter (as we are positing in our case of mollusk‐like creatures), then it does not have a human nature and is not human. Since human matter is clearly mammalian primate matter of a certain kind and these extraterrestrials would have mollusk‐like matter, they cannot have a human nature. To include extraterrestrials as another species of rational animality might require a reworking of the classical definition of the human being by including some further explanation of the specific difference needed for the definition.
Because it sets up the question of the immortality of the souls of extraterrestrial beings, the second crucial aspect about our hypothetical case is the intelligence of extraterrestrial life. For St. Thomas, if the soul of something is intelligent, it is immaterial and if it is immaterial, it is immortal. St. Thomas's argument for this is most succinctly found in Summa theologiae I Q. 75, art 2c. The criterion for intelligence in Thomistic philosophy of knowledge is the ability to grasp in universal concepts the intelligible content of kinds that are part of the natures of things. This argument builds on what was stated before about nature. Since natures make things intelligible, there must be something intelligible that can be recognized or abstracted. The structure and intelligibility of the natures that are constitutive principles of material beings can be grasped in some way by the intellect.Footnote 14 When we know things, there is no material part of the other thing that enters our intellect. But since there is nothing material of the thing known that enters the intellect of the knower, the intellect must be immaterial. Since (as the scholastic axiom has it) everything that is received is received according to the mode of the receiver, if the received intelligible aspect of a nature is immaterial, it must be received in an immaterial way by the receiving intellect. Thus, the thing that knows immaterial things must be immaterial.
This philosophical model of human cognition proving the immateriality of the human soul could work just as well for extraterrestrial life forms. If our hypothetical species shows in some way that they grasp things by means of universal concepts, then we can be sure that they have immaterial souls according to the metaphysics of St. Thomas. According to article 6 of the same question,Footnote 15 corruption occurs when a composite thing becomes separated into discrete parts, especially when the matter‐form unity of a being is disintegrated. However, since the soul is form and it is immaterial, it cannot have parts that are not intrinsic to it and thus can those parts cannot be separated from it. If the soul has no parts that can be corrupted, then it is incorruptible and if it is incorruptible, it cannot be destroyed except by God taking away the act of existence from it directly. Therefore, if our hypothetical extraterrestrials are intelligent, we know that they have immortal souls.
In this section, it was established that, according to principles of Thomistic metaphysics, intelligent extraterrestrial life forms with radically different matter than human beings do not have human natures and that their rationality (i.e. their ability to receive immaterial intelligible concepts by the intellect) is a guarantee of an immortal soul. Both of these conclusions set up crucial problems in soteriology, which will be covered in the next section.
II
While a hypothetical Thomistic philosophical cephalopodology could be generated on the basis of the metaphysical principles of St. Thomas Aquinas with relatively little speculation, theology is a different science than philosophy and requires revelation because it includes truths that are not accessible to unaided human reason.Footnote 16 Any investigation into the theological status of our hypothetical extraterrestrials will be extremely speculative and there are many options open to the theologian who wishes to remain within the teachings of the Catholic faith. The following will be an attempt to apply principles in the thought of St Thomas Aquinas on Christian revelation to this hypothetical case. St. Thomas himself did not speak about the sort of case we are envisioning here, but his theological anthropology can provide us with several options regarding a hypothetical theological cephalopodology. What will follow both in this theological cephalopodology and in the soteriology of extraterrestrials will mainly be a consideration of different options and arguments from fittingness.
While it is entirely theologically possible that our hypothetical species would not ever have a fall from grace, other than noting that it is theologically possible that this unfallen species could die,Footnote 17 issues of space only allow our investigation of various ways our hypothetical species could have fallen. St. Thomas formally defines original sin as the loss of original justice, which St. Thomas states, “consists in man's will being subject to God.”Footnote 18 Original justice not only held humanity in union with God, but it also held all of the lower powers of the soul and body subject to the higher, rational powers of it.Footnote 19 Thus, original justice was a gift to the entire person of Adam, body and soul.Footnote 20 When this was lost, a certain corruption of human nature occurred. While the intrinsic principles of human nature (i.e. matter and form, soul and body) and those that flow from them were not destroyed or diminished, the inclination of the soul to virtue was diminished and the harmony of body and soul given by original justice was entirely destroyed.Footnote 21
Adam's deliberate turning away from God is a fault in him and, because he is the one from whom all subsequent human nature came, the fault is inherited by all who share that nature.Footnote 22 Aquinas relies on an incorrect medieval biology that held that it was only the father that contributed an active principle for the offspring. With current biology, it is clear that both parents contribute living and active material to offspring, but, since Eve also fell, this does not alter St. Thomas's theological point. In Adam and Eve, all of humanity was virtually contained because all human beings draw human nature from them. Since the human soul is immaterial (as shown above), it cannot be made from the material contributed by the parents; it must be directly created ex nihilo by God.Footnote 23 While St. Thomas is also working with an obsolete biology concerning when God makes the soul, his philosophical and theological points once again still hold and the soul, we can now say, is created by God and infused into the human body at conception. The soul, however, inherits the fault of original sin because it is the form of the body and was created to suit the human nature inherited from Adam.Footnote 24 Original sin is not a fault that is attributed to the individual as though it were a voluntary moral fault attributed to her, but because she shares the same human nature that fell in Adam, it is attributed to her as a part of that whole, just as a hand is not individually guilty in a murder but only as part of the whole.Footnote 25 All of humanity is fallen because we derive our nature from our fallen first parents who lost original justice.
Interestingly for our purposes, the personal sins of parents in whom the entire human species are not virtually contained is not passed down to future generations.Footnote 26 The reason is that personal sins are accidents of the soul that do not effect the nature of the body. While certain accidents of the body can be passed down from generation to generation, accidents of the soul cannot because the soul (as stated above) is directly created by God and suited to the human nature and body, not from the accidents of the soul of the parents.Footnote 27 No personal sin is inherited by subsequent generations because these are accidents of the soul and do not have the power to change human nature. Even the sin of Adam and Eve is not inherited as a personal fault by their descendants, but it is rather a defect of the nature that is a fault of humanity collectively.
St. Thomas's next point, however, is the most crucial one for the contemporary debate about the soteriology of extraterrestrials. Any fall of extraterrestrial life could not be caused by human beings in the theology of St. Thomas Aquinas. While other theologians in the Christian tradition have a strong belief in the fall of human beings introducing disharmony into the cosmos, St. Thomas holds that the natures of other animals were not changed by the fall.Footnote 28 In the context of speaking about man's natural dominion over the animals that was lost in the fall, St. Thomas states that the loss of dominion was due to the damaging of human nature.Footnote 29 The objection states quite clearly that natural carnivores (such as lions and falcons) would not have been herbivores before the fall because the fall of man did not affect the nature of the animals.Footnote 30 The natures of the other animals were not changed by the fall in St. Thomas; only human nature and its relationship to the universe. Therefore, it is not the case that the fall of extraterrestrial life can be included under the same fault as the fall of humanity. Even if there were a more substantial effect that the fall of man had on the universe, the fall of another extraterrestrial species would have had to be a deliberate and moral fall, as opposed to the non‐moral disruption of the universe caused by humanity in other authors of the Christian tradition. Because of this separate fall, the fall of an extraterrestrial species is distinct from and not directly caused by the fall of humanity.
With all of this established, it is possible to speak of the possibilities of the fallen nature of our hypothetical extraterrestrials. It is possible that the progenitor(s) of the entire species (whoever they may be; extraterrestrial biology may be radically different from terrestrial ones, among which there is already a diversity of natural reproductive methods) fell in a similar way to Adam and Eve, lost friendship with God, and thus are in need of salvation in a similar way to humanity.
However, there is another possibility that is conceivable in the theology of St. Thomas. It is possible that the original progenitor(s) of the species did not fall, but subsequent generations of the species did sin. As stated earlier, personal sins of later generations are not passed down to subsequent generations both because sins are accidents of the soul and because the entire species is not virtually contained in subsequent generations. The sin of each would not condemn the entire species. Therefore, it would be possible for some of the species to be in need of salvation and some to still have that right relationship with God.
The crucial conclusion of this section was the fact that fallen extraterrestrial life would not have been caused by the fall of human beings both because they do not share human nature and because they are not descendants of Adam. Three different possibilities for extraterrestrial life were discussed: the possibility of unfallen extraterrestrials, the possibility of an original fall wounding the alien nature in a similar way as human nature was wounded, and only part of the species giving in to wickedness while leaving the nature of the species intact. The next section will show that, since any fall of extraterrestrial life would not be caused by the fall of man, extraterrestrial live could not be redeemed in the same way as humanity was.
III
Now the preliminary work has been done to speak about Thomistic soteriology and its application to the anthropology and cephalopodology stated above. Jesus Christ is the Second Person of the Blessed Trinity who assumed a full human nature (body and soul with all of its powers and faculties) of the Blessed Virgin Mary and united it with His divine nature for our salvation. While the merits of His actions were infinite, they were applied to human beings because of His assumption of our human nature.
For St. Thomas Aquinas, the Incarnation is not the only way that humanity could have been saved. He states that the Incarnation was ‘necessary’ for salvation in a qualified hypothetical sense.Footnote 31 Since the Lord willed to save us in this way and it is sufficient for our salvation, the Incarnation can be said to be necessary to that end much in the same way that if I have resolved to go to Boston from Washington by way of New York City, it is necessary that I pass through New York City to fulfil my resolution. It was fitting that the Incarnation occur because human nature was in need of salvation and it is by the Incarnation that humanity is saved, but it could have happened another way.Footnote 32 For instance, it would have been perfectly in keeping with God's justice to simply forgive humanity of its collective fault without requiring satisfaction for it.Footnote 33 Since the fault of humanity was an offense against God, then it was well within the bounds of justice for the one against whom a fault was committed to completely dismiss the offense against him. As we will see, St. Thomas holds that what God actually chose to do is even more in keeping with God's mercy and justice. The infinite power and creativity of God ought not be unnecessarily curtailed in solving this problem.
St. Thomas states two different kinds of reasons for the Incarnation in the first question of the third part of Summa theologiae. The first are ways that the Incarnation positively helps to build us up through the theological virtues, providing us an example as to how to live, and allowing us the participation in the divine nature.Footnote 34 The second set of reasons concern the ways in which the Incarnation helps us in “withdrawing from evil.”Footnote 35 St. Thomas uses the classical model of atonement in a reply to the second objection of this article.Footnote 36 It is fitting for divine justice that the ones who made an offense to the Divine should make recompense for it, but since they are not able to repair an infinite fault, it would take someone of infinite majesty to address it. Jesus Christ, God and man, could redress the wrong because He was truly man and truly God. He fulfilled the fault by His infinite sacrifice and did it as man. The two aspects that are crucial for the soteriology of St. Thomas Aquinas are the restoration of the divine image in human nature as union with the divine nature and the satisfaction of the fault of original sin on behalf of humanity.Footnote 37 These are the two positive points that occur in this question's reasons for the Incarnation.
St. Thomas is insistent that humanity is saved by the God‐man undergoing the Passion, Death, Resurrection, and Ascension, but it is the explanation of the Passion that is the key to his soteriology. St. Thomas holds it as divinely revealed that the Passion is a constitutive aspect of our salvation and devotes a great deal of time to it.Footnote 38 This is for three reasons: for our salvation, so that the humiliation of the Passion should merit Christ's exaltation, and that God's prophecy through the prophets should be revealed.Footnote 39 None of these are very explicit, but they all are dependent on scripture and are clarified by a reply to an objection. St. Thomas states that God's justice was fulfilled by Christ's passion making satisfaction for the sin of humanity.Footnote 40 Once again stressing the inability of humanity to satisfy for sins by its own power, St. Thomas states that it is also in accordance with God's mercy that God should suffer for us to make satisfaction when we could not. Just as with the Incarnation, St. Thomas states that God could have saved humanity without the Passion, but that it was fitting that the elements of the fall should be used to undo the effects of the fall. It was fitting that humanity should make up for humanity's fault, but it was only possible for God to make up for it. Throughout, St. Thomas points to the importance of Christ's modelling behavior for us as a reason for the Incarnation, but the ontological satisfaction is obtained through the reversal of the most important aspect of Adam's sin; Christ's perfect obedience undoes Adam's disobedience.Footnote 41
St. Thomas fleshes out the ways in which Christ's supreme obedience to the will of the Father merited our salvation. Christ's obedience and charity atones for the offence of humanity because it gives the offended something that He loves infinitely more than He hated the offence against Him.Footnote 42 The first, and most important, is the supreme charity with which Christ suffered for us. The perfect love of a human being, which is the perfect love of the God‐man, more than makes up for the disobedience of Adam and Eve because of the greatness of His charity, the caliber of His character (being God), and the extensive suffering He bore.Footnote 43 At the end of the day, it is the love and obedience with which Christ lives His human life (especially in the Paschal Mystery) that is efficacious for salvation.
Even with this having been established, there is a major question regarding how the objectively infinite sacrifice of Christ's lovingly‐lived human life is applied to human beings. How is the sacrifice of one man efficacious for the entire human race? Building on the divine command and incorporating the theology of St. Paul, St. Thomas holds that the sacrifice is efficacious for all human beings because, by His Incarnation, Jesus Christ became the head of the Church and in fact established the Church as His mystical body.Footnote 44 Christ's Passion redeems us by our being incorporated into His mystical body and thus our sharing in His saving actions.Footnote 45 Just as all human beings were virtually contained by nature in Adam and Eve and the fault of original sin was passed on to them through generation, all the merits of Christ's life are contained in Him and are poured out upon the members of His mystical body of which He is the Head. It is striking that St. Thomas uses the same metaphor to describe salvation in Christ to original sin. Recall that above in the De malo, St. Thomas described the fault that obtains on human nature as the fault of the hand when it is truly the head that is responsible.Footnote 46 In the same way, the merits of the head are attributed to the members of the body, not because of any actions of the body without the head, but precisely because they are involved in the actions of the head. How are human beings incorporated into the mystical body of Christ? By baptism (received with faith) or the faith that is a desire for it, one is incorporated into the mystical body of Christ.Footnote 47 Since baptism is the remedy of original sin for human beings, it seems as though one must have a human nature to undergo baptism.
IV
The sacrificial life of Jesus Christ redeemed those who have a human nature and are incorporated into His sacrifice by baptism. Because of the crucial role that assumption of a human nature plays in Chalcedonian and Thomistic soteriology, it is not possible to simply transfer the effects of the life of Jesus Christ to other intelligent beings who are not sharers in human nature.
Before we continue on to some possible Thomistic approaches to different theological positions of extraterrestrials, it may be beneficial to give a survey and evaluation of the existing scholarly literature on the subject and an evaluation of the major trends in light of the Thomistic principles of soteriology mentioned above.Footnote 48
There are three main schools of theological thought on the issue of the soteriology of intelligent extraterrestrial life. The first and most commonly held by contemporary theologians is that any fallen intelligent extraterrestrial life would be incorporated into the sacrifice of Christ, much in the same way that it applies to human beings.Footnote 49 The entire cosmos fell in Adam's sin and thus the entire cosmos is redeemed in Christ. The second is that there would be an Incarnation for every intelligent species which fell from grace. The third is a respectful agnosticism about God's plans for intelligent extraterrestrial life, with a special emphasis on divine freedom not necessitating either of these options.
The major emphasis that the first school has followed is Christ as the definitive revelation of God and the centrality of the Incarnation to all creation. One scholar articulates the universal domain of the Incarnation very well.
It happened, in the fullness of time, that the Word became incarnate as a Jewish male of first‐century Palestine. But he did not come only to save males, or Jews, or his First‐century contemporaries … Just as the mission of Christ bridges the gap between sexes, races, times, and places, so too does it bridge the gap between species and galaxies. For the ultimate point is not so much that Christ became a male in Palestine, or even that he became homo sapiens on earth, but that he entered his own creation. In the Incarnation, the whole created world was assumed; on Calvary, the whole created world was likewise redeemed in the universal act of salvific love.Footnote 50
After an investigation of Christology concluding that “the weight of theological speculation seems to hold very strongly for the unicity of the Incarnation,” Graebe sees the possibility of the soteriology of extraterrestrials as extremely important for missiology. Calling the discovery of extraterrestrial life “analogous to the discovery of the New World in the 16th Century,” Graebe sets up the clear argument of the first school that the salvation of intelligent extraterrestrials would be in Christ in nearly the same way as human beings would be saved.Footnote 51
While Graebe is correct in his assessment favoring the unicity of the Incarnation and the Cross being the axis mundi “on which the entire world—indeed, the entire cosmos—hinges,” a major question must be raised (as is clear from above) about the role of human nature in the Incarnation. Specifically, if extraterrestrials are in the same circumstances as natives of the New World, will extraterrestrials be incorporated into the sacramental life of the Church?Footnote 52
Our conclusion must be no. Because the Redemption was effected by means of a human nature to redeem humanity, baptism into Christ's death and Resurrection requires a human nature for the proper reception of the sacrament. Just as the Church has no authority to confer the sacrament of orders onto a woman,Footnote 53 so I argue that human nature is essential for reception of the sacraments. Extraterrestrial life (as argued above) lacks this nature, so extraterrestrials do not receive the sacrament of baptism validly nor are they incorporated into the Mystical Body of Christ in this way. As will be seen below, a lack of a human nature does not exclude intelligent extraterrestrial life from salvation, but it does exclude it from entering into the graces of Christ in the same way that Christ established it (by means of his human nature) for humanity.
While the major advantage of the first school is that it takes the Incarnation as the awe‐inspiring event that it is, it has a crucial flaw in that it neglects the importance of nature in soteriology. Without the crucial point of human nature being the instrument by which God chose to redeem us, why would it be essential to the Tome of Leo and the Chalcedonian definition? When Christ saved us and established the sacraments, He did it though His human nature and not just His divine nature. Our human nature was the way by which we are redeemed and are incorporated into the mystical body of Christ and this cannot merely be transferred to something with another nature given the centrality of the concept of nature to the Church's interpretation of the Redemption.
The most prominent proponent of the second school highlights the main presuppositions of this school very well. Pierre Teilhard de Chardin, one of the earliest and most influential Catholic commentators on the subject, insisted that, since death and corruption were in the universe before humanity, original sin is in reality “the essential reaction of the finite to the creative act. Inevitably it insinuates itself into existence through the medium of all creation … Strictly speaking, there is no first Adam. The name disguises a universal and unbreakable law of reversion or perversion—the price that had to be paid for progress.”Footnote 54 Because of this (heretical concept of) the inevitable and universal domain of sin, Teilhard de Chardin accuses Catholic dogma of being nearly inextricable from geocentrism and anthropocentrism.
The idea of an earth chosen arbitrarily from countless others as the focus of Redemption is one that I cannot accept; and on the other hand the hypothesis of a special revelation, in some millions of centuries to come, teaching the inhabitants of the system of Andromeda that the Word was incarnate on earth, is just ridiculous. All that I can entertain is the possibility of a multi‐aspect Redemption which would be realized, as one and the same Redemption, on all the stars ‐ rather as the sacrifice of the mass is multiplied, still the same sacrifice, at all times and in all places.Footnote 55
Teilhard de Chardin is here falling into a typical problem for the scholarly literature asserting the necessity of multiple Incarnations: the scandal of particularity. From the history of the seemingly insignificant Jewish people to the outcast of first‐century Palestine with whom Jesus spent most of His earthly life to all of the uneducated, small, and weak of the world who have shamed the strong in Christ, it is clear that the God of Christianity favors the small groups of people “arbitrarily chosen from countless others.” The same argument that Teilhard de Chardin is using against there being only one Incarnation would also exclude the only confirmed Incarnation and also tells against every way we know God works. This cannot be a valid approach to a soteriology of extraterrestrials in the Christian tradition.Footnote 56
Teilhard de Chardin does highlight important aspects in the soteriology of extraterrestrials which theologians must address, such as God's care for other extraterrestrial life and original sin. These problems do not necessitate multiple Incarnations, however. The remainder of this paper will be attempts to sketch possible avenues of divine action other than an Incarnation for each intelligent species or the direct incorporation of non‐human intelligent life into the sacramental life of the Church. While one can never limit divine power and creativity to do what human beings cannot conceive, based on the teachings of St. Thomas Aquinas, this paper will merely suggest non‐exhaustive avenues of proceeding.
V
There are two main possibilities concerning the theological state of intelligent extraterrestrials as mentioned above: unfallen and fallen. In a scenario where they are unfallen and die, it is fitting that they should be handled as the angels are. As argued above, these creatures would have immortal souls, but would never have transgressed the commandments of the Lord. The lack of a human nature does not necessarily preclude God's grace. Since these beings would not need redemption, after death, the good disposition of their wills could be confirmed by the grace of God and they could enjoy the beatific vision as the angels do as members of the Body of Christ (but not a sacramental way).Footnote 57 It would be fitting that they be a part of the Resurrection of the dead at the end of time because they are essentially body‐soul composites and it is fitting for them to be restored to their whole state at the Resurrection of the dead.
If our hypothetical extraterrestrials have fallen as a species as human beings did, there are more options. As stated above, many scholars have proposed that there either be as many Incarnations as there are species in need of salvation or that all rational extraterrestrial life ought to be baptized. Though the first option does respect the Chalcedonian necessity of a common nature for salvation, it is highly unfitting. While it may be (as St. Thomas states)Footnote 58 well within the power of God for any of the Persons of the Trinity to incarnate as the Son did for humanity, the awe inspiring entry of eternity in time seems to be the definitive intervention of God in the universe. While it is possible for it to be repeated, the Incarnation is such an important and pivotal event in the universe that it would not be fitting for such an event to be repeated.Footnote 59
Something that the third school of thought stressed was that it is entirely possible for God to use other means to heal intelligent non‐human extraterrestrials of original sin. It is entirely possible that God could use some of the possibilities St. Thomas enumerated that were perfectly in line with God's justice and mercy. God could, in His justice, allow the extraterrestrial species be condemned to Hell for their sins. More hopefully, God could forgive this species of its sin entirely without requiring satisfaction. Perhaps He could also couple this action with innate knowledge of it in the minds of the species. While St. Thomas sees that there are no innate ideas in human nature because of its particular psychology, it is entirely possible that a different species could have innate ideas. With this innate knowledge of forgiveness, grace could be given directly to individuals without a community and then accepted or refused by individuals. This option would be fitting if the species also had very little need for physical community and support. If the individuals of the species thrived in solitude rather than in community, it would be a very different kind of being than human beings, but it would be possible and fitting for God to save them in this way.
As stated above, a problematic approach, at least based on the theology of St. Thomas Aquinas, would be for us to attempt to baptize fallen extraterrestrials. It certainly seems as though being incorporated into the mystical Body of Christ by baptism requires a human nature because this is the remedy for the human fall, which, as we saw, must be distinct from an extraterrestrial one. However, St. Thomas does say that the angels have been incorporated into the mystical body of Christ in an analogous way because of their unity of will with God.Footnote 60 It is possible that the unity of will (cooperating with grace) could also suffice for extraterrestrial life forms to be incorporated into the mystical body of Christ without needing a human nature. This will in union with the divine will may even be meritorious for salvation, as the patriarchs were saved by the desire for Christ.Footnote 61
There is no necessity for there to be multiple incarnations to save extraterrestrial species be saved, even in a fall like Adam's, for there is nothing preventing God from simply forgiving without satisfaction, as it was possible for Him to do with humanity. Given the magnitude of God entering His creation by uniting a human nature with Himself, it seems unfitting for such a tremendous action be repeated. Without further revelation, it is not possible for us to simply apply humanity's salvation in Christ to beings that do not have a human nature. As far as we can tell, baptism is for those beings that have a human nature because it is by a human nature (as an instrumental cause) that our salvation was accomplished. It seems as though one needs a human nature to be incorporated into the mystical body of Christ by baptism. In the case where only certain individuals of a species have sinned, it is even within the power of God to forgive each individually, each in accord with its own repentance. There are any number of ways that intelligent extraterrestrial life could be saved by the infinite power and creativity of God that do not involve multiple Incarnations or the application of the sacraments to non‐human beings.
Conclusion
It is hoped that this paper has highlighted the centrality of human nature to the Incarnation and soteriology. Through the philosophical investigation of a hypothetical rational extraterrestrial species, it was established that any species that had radically different matter than humanity could not have a human nature. That the Fall of Humanity transmitted original sin only to those who have a human nature and that the Incarnation pours out grace upon those sharing the nature that was assumed are foundational both to Thomistic soteriology and to Catholic soteriology as a whole. Thus, it was argued that rational extraterrestrial life forms would not participate either in the Fall of Humanity or the Incarnation of Jesus Christ. While this does not exclude the possibility that such a species would have a fall, there are many ways in which St. Thomas holds that God could choose to reconcile them to Himself. The lack of a shared human nature makes the baptism of extraterrestrials improper and multiple Incarnations unnecessary.
