Cutting the Ethical Pie for Engaging ETI: An Adventure in Astro-Ethics

by Ted Peters

Through the eyes of the Kepler Space Telescope, planet hunters have just spotted two Saturn-like transits orbiting a single star. Might they have an Earth-sized companion? In addition, a possible litter of seven planets has been detected orbiting a sun-like star, HD 10180, only 127 light-years away (Grossman). The day of contact with extraterrestrial intelligent life (ETI) may be tomorrow.

What shall we do when we meet them? How shall we respond to contact with intelligent beings inhabiting exoplanets? What shall we say when extraterrestrials ask us questions? How shall we treat intelligent beings from another world? Despite all the Sci-Fi movies we’ve seen, and despite what UFO aficionados tell us, we Earthlings just may not be ready to engage ETI.

Thinking ahead about our response to contact with ETI I call Astro-Ethics (or Astro-Bioethics). An ethicist theorizes about moral behavior. Ethics is defined by the late Paul Ricoeur as thinking about “living well with and for others in just institutions” (Ricoeur, 330).” I put “astro” in front of “ethics” so we can speculate about how to live well with alien neighbors in just institutions.

ETI might be really other to us. They may be so different that at first contact we might have to work hard just to discern whether they’re living and whether they’re intelligent.[1] Or, maybe not. Maybe the laws of physics and laws of evolutionary biology are such that alien intelligent beings--though the result of a 2nd genesis somewhere else in space--resemble us enough that we can bridge the gap of otherness. Let us work temporarily with this assumption: ETI, though other, still take a form that reasonably resembles homo sapiens on Earth.

With this first assumption in mind, let’s consider the alien community as a moral community - that is, as a community with whom our relations can be understood in ethical terms. What are the possibilities? I see three. One or more of the three following are possible: we might engage (1) inferior aliens: extraterrestrial biotic individuals who are inferior to us (less evolved); (2) peer aliens: residents of an exoplanet who may have followed a similar path in evolutionary development and whose level of intelligence is comparable to our own; or (3) superior aliens: perhaps having evolved over a longer period of time, higher in intelligence, more advanced in science and technology, and better than we are in many identifiable respects. Here is how we cut the ethical pie for engaging ETI.

Our second assumption will be this: when it comes to the criterion by which we measure inferior, peer, and superior, it will be rational intelligence. Why? Because most commentators on human enhancement who weigh in on the future of humanity believe intelligence to rank among the highest of human values (Harris, 2). Further, astrobiologists hypothesize that evolutionary history has a built in entelechy that leads toward increased intelligence over time (NASA). Cyber dynamo Ray Kurzweil provides an example of the prevalent evaluation of evolved intelligence: “The purpose of the universe reflects the same purpose as our lives: to move toward greater intelligence and knowledge” (Kurzweil, 372). Has this assumption been proven? No. Cornell exobiologist Carl Sagan recognizes that this belief structure is based on speculation rather than sufficient empirical evidence to deem it scientific. “I would guess that the Universe is filled with beings far more intelligent, far more advanced than we are. But, of course, I might be wrong. Such a conclusion is at best based on a plausibility argument, derived from the numbers of planets, the ubiquity of organic matter, the immense timescales available for evolution, and so on. It is not a scientific demonstration” (Sagan, 1994, 33). Still, despite its lack of scientific status, space scientists largely assume that biological evolution over time leads to increased intelligence. This belief that the evolution of life is aimed toward enhancing rational intelligence is rife among astrobiologists; and intelligence provides the criterion for measuring evolutionary advance. Of course, one could imagine a different criterion. For example, one could imagine a criterion such as altruistic love. We would then rank terrestrial as well as extraterrestrial civilizations according to their lovingness. But, alas, no one I can find in this discussion appeals to anything other than intelligence. So, intelligence is what we’ll speculate on here.

Now, cutting the pie into thirds - inferior, peer, and superior--is not quite enough. Our ethical deliberations need in addition to distinguish between an alien civilization that might be (a) hostile to us; (b) neutrally peaceful; or even (c) salvific - that is, helpful to the extent of saving us from our own self-destructive habits. Our initial moral posture should respond appropriately to the initial posture of our alien neighbors.

  Hostile Peaceful Salvific
Inferior   X  
Peer X X  
Superior X X X

Response on the part of us Earthlings to contact with ETI is what we’re now asking about. So, the ethical orientation here will build upon a sense of moral responsibility. As the etymology of the Latin, respondere meaning to answer, suggests, responsibility ethics answers questions raised by our changing situation (Jonsen). Establishing a new relationship with extraterrestrials would prompt many questions. And an ethic of responsibility would seek to spell out just how best for earthlings to respond. Further, the idea of responsibility includes care, care both for the health and welfare of planetary life on earth but also the health and welfare of our new space neighbors. The conditions and imperatives arising from the new situation will suggest forms or frameworks within which to formulate our moral responsibilities.

What about non-intelligent life? What about our response to the discovery of microbial life on Mars or the moons of Saturn? Margaret Race and Richard Randolph have proposed four underlying principles for developing an ethic appropriate to the discovery of non-intelligent life in our universe: (1) cause no harm to Earth, its life, or its diverse ecosystems; (2) respect the extraterrestrial ecosystem and do not substantively or irreparably alter it (or its evolutionary trajectory); (3) follow proper scientific procedures with honesty and integrity during all phases of exploration; and (4) ensure international participation by all interested parties (Race and Randolph, 2002; Race, 2007, p. 495). For the discussion that follows, microbial life will be thought of as non-intelligent life. We will focus here on various forms of life we deem to be intelligent.

Has anybody already thought about responding to alien intelligence? Yes. SETI (Search for Extraterrestrial Intelligence) Institute has already offered a statement: The Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence. The thrust of SETI’s nine principles is to follow scientific best practices, seek independent confirmation to establish credibility, and announce the discovery only after consultation with international leadership (SETI, 1990; Randolph and Race, 2002). In what follows we will refine what SETI has already done by cutting ETI’s ethical pie into differing moral communities.

Do we have empirical knowledge that ETI exist? No. “No unambiguous signals from extraterrestrial intelligence have been detected” (Dick, 1:317). Yet, the search goes on. As the search goes on, we will assume that someday, sooner or later, contact with alien intelligence will occur. Can we get ethically ready?

The Inferior ETI Slice

If the alien intelligence we Earthlings find ourselves engaging with is substantially inferior to ours, then we must ask: how should we morally respond? One obvious analogy leads us to ask: how do we on Earth treat our intelligent neighbors whom we similarly designate as lower on the intelligence scale? I’m talking about our animals.

On the one hand, animals are edible and dispensable. Animals can be sacrificed in medical research to develop therapies that will benefit only human persons. Animals are less than human, we assume. On the other hand, we human beings have a sense of responsibility toward the welfare of animals. We respect them as intelligent being. And we are concerned about preventing suffering to animals. In some instances, we exert considerable energy and effort to preserve their species from extinction and to insure the health of individual animals. In the case of pets, we love them to a degree that rivals loving our own family. In sum, we have inherited a double relationship to our inferiors already here on earth. By analogy, what might we expect when we engage ETI who remind us of our animals?

Important for our application to the upcoming ETI question is what we have assumed to be our ethical criterion for rendering moral policy. Is the animal rational in the same sense that we homo sapiens are rational? No, says the tradition beginning with Aristotle. The human is the distinctively rational animal. The separation of humanity from the animal world due to a separation on the scale of rational intelligence justifies an ethic whereby the superior human exploits the inferior animal. “Irrational animals are natural slaves, and no positive human moral or political categories can govern humankind’s relations with them” (Fellenz, 1:75). Yet, we might ask: is rational intelligence the only ethical criterion? No, say some moralists. Feeling counts too. We rational humans have a moral responsibility to care for less intelligent sentient beings. By extension, our moral commitment to protect humans from suffering should be applied to animals. How an animal feels is morally significant. “Animal welfare is most crucially a matter of the animal’s subjective experience - how the animal feels, whether it is in pain or suffering in any way” (Rollin, 1:82).

With this double sided experience of relating to animals on Earth in mind, our first ethical question in the case of engagement with inferior ETI would be: by which criterion do we orient our ethics? Should we justify the exploitation of ETI on the grounds of its lower intelligence? Or should our responsibility for the welfare of ETI take precedence? Now, we could ask the question another way. Which of these two habits should we set as our moral standard: exploitation of ETI for our own use? Or protection of ETI from suffering? More than likely, all of these alternatives would inform the policies we develop.

Even if we earthlings commit ourselves to caring for the alien as other, we would not impute dignity to ETI whose level of rational advance falls significantly short or ours. We very well might show them respect along with care, to be sure. If motivated by faith, we might view ETI as creatures precious in the eyes of God. If we look at inferior ETI through economic glasses, more than likely we would exploit lesser intelligent ETI for increased terrestrial prosperity. We might work out terms of exchange, or, more likely, simply set up an infrastructure for ongoing exploitation. Would we exploit with moral abandon? Or, would we exploit only to the limit set at the point of detriment to the welfare of the ETI themselves?

All this presses on the matter of our moral responsibility. In terms of our responsibility, I believe we should take the initiative to extend concern for the welfare of such ETI on the model of our current concern for the subjective quality of animal experience. We should do what we are able to protect ETI from suffering and enhance their experience of wellbeing. This trumps exploitation, though it would not entirely exclude it.

The Peer ETI Slice

Just institutions will frame our ethical deliberation if we conclude that ETI are our peers in rational intelligence. We might begin by invoking the Golden Rule. The Golden Rule, sometimes referred to as the ethic of reciprocity, can be found among the ancients in the Code of Hammurabi and in many of the world’s religions. In Confucius’ Analectswe find: “Never impose on others what you would not choose for yourself.” A Hindu variant is found in the Mahabharata: “One should never do that to another which one regards as injurious to one’s own self” (Wikipedia).

In the West, the Golden Rule has grown into the modern concept of human dignity. Jesus sowed a seed: NRS Matthew 7:12 "In everything do to others as you would have them do to you.” One branch of the resulting growth is Immanuel Kant’s Categorical Imperative. For Kant, the formal principle from which all moral duties are derived is this: “I ought never to act except in such a way that I also will that my maxim should become a universal one” (Kant, 70; Narveson, 248). In sum, we should treat peers as equal to ourselves; and we should care for their welfare just as we would care for our own.

Jesus’ Golden Rule and Kant’s Categorical Imperative have greatly influenced the value system of the Enlightenment and, hence, the modern culture of which we are a part. If we find that ETI resemble us enough to be considered our peers, then we might invoke the value system of the Enlightenment - that is, we might invoke the Golden Rule and impute dignity to our space neighbors. Our moral disposition would be to approach our new neighbors with operative values such as equality, liberty, dignity, justice, and mutuality. We would strive to establish just institutions.

When it comes to dealing with ETI as individuals, we would impute dignity to them - that is, we would treat each as a moral end and not merely as a means. “Act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end,” wrote Kant (Kant, 96). In a more contemporary and theological medium, we might say: “human dignity is the inherent worth or value of a human person from which no one or nothing may detract” (Alan Falconer in Childress and Macquarrie, 278). Might we impute dignity to ETI? Might we treat them with dignity? Might “dignity” become the label for identifying our responsibility?

The imputation of dignity toward ETI should be accompanied by a denial of our own right unilaterally to exploit them. We might encourage the development of bilateral commerce, of course; but we should do so presuming the equality and liberty of our trading partners. We might also restrict our intrusion into their ecosphere. We might adapt for ETI the Race and Randolph principle aimed at ETNL: “respect the extraterrestrial ecosystem and do not substantively or irreparably alter it (or its evolutionary trajectory).” In sum, the ethical principles we invoke to deal with peer ETI might draw upon our Enlightenment values. We could formulate principles applicable to ETI which we now invoke to maintain terrestrial justice and peace.

Hostile? Peaceful? Salvific?

Watch out! Look to the heavens for a possible invasion! This is the message to Earth delivered in the spring of 2010 by physicist Stephen Hawking in a Discovery Channel documentary. Some extraterrestrials are likely to be intelligent and perhaps even more evolutionarily advanced than Earth’s homo sapiens, said the UK scientist. Hawking warned that contact with such a species could be devastating for humanity. If alien intelligences are like us, we can expect them to raid, exploit, or even conquer our planet. “We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet. I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonise whatever planets they can reach.” He concluded that trying to make contact with alien races is “a little too risky...If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn’t turn out very well for the Native Americans” (Hasking). Given the human precedent, spacelings like us might bring to Earth war and genocide.

Hawking’s speculations give us pause. Perhaps some alien intelligences will be hostile. Before proceeding to ethical analysis of our third slice--superior ETI--we might wish to cut our three slices into smaller pieces. Perhaps we can leave the first slice, inferior ETI, without division; because we’ll assume that Earth’s technological and military power will suffice to render such ETI pacific. What about the other two slices? I suggest we divide peer ETIs into two subcategories: hostile and peaceful. And I suggest we divide the superior ETIs into three subcategories: hostile, peaceful, and salvific. Once we have discerned that ETI are our equals or our superiors in technology and perhaps in intelligence, we will need to ask whether or not they pose a threat to earth’s security and wellbeing. How we answer this question may map and partially guide the moral direction we take.

If Hawking is right--that we homo sapiens are capable of war and genocide among ourselves--then what can we expect when we meet aliens who are like us in this respect? What have we learned from our own experience with ourselves? We have learned that anxiety associated with insecurity leads us homo sapiens to strike out with violence (Peters, 1994). We can safely forecast that we on earth will find ourselves uneasy, on the verge of violence, until we can be assured that the ETI we contact mean us no harm. Whether the high minded among us find it moral or not, the reality is that no rational discourse about ethics can take place when our anxiety is high and security is low. To determine whether ETI are a threat or not will inescapably become our first priority.

In the event that the ETI in question are in fact hostile, then we will find ourselves working within an ethical framework that includes both the imputation of dignity mentioned above and our pressing need to protect our planet from alien exploitation or damage. We know from experience that whenever we are confronted with a hostile enemy from without, we find ourselves within our society compromising human dignity. Our political leaders try to persuade our society that our targeted enemies should be reduced to “inhuman” if not demonic status. This justifies going to war. What this indicates is that the social psychology of self-defense pits human dignity against the mustering of military support. Security trumps dignity. If threatened by alien hostility, we can forecast that military rhetoric will attempt an equivalent of dehumanizing and, hence, de-dignifying the ETI enemy. A nation’s leaders simply cannot embrace Jesus’ peace ethic of loving our enemies combined with turning the other cheek (Matthew 5-7). So, as difficult as it may sound, we will need an ethic that affirms the dignity of ETI while rallying our earth allies in planetary defense. We might need to adapt for peer ETI the Race and Randolph principle, “cause no harm to Earth, its life, or its diverse ecosystems,” within a tense relationship to the wider ethical principle of imputing dignity to our extraterrestrial peers.

In the event that peer ETI prove to be neutrally peaceful or even benevolent, then the principles giving expression to Enlightenment values should prevail without challenge: equality, liberty, dignity, and mutuality. We on Earth will establish just institutions through which we can express care for the other, for the alien.

The Superior ETI Slice

It is difficult to imagine up. It is easier to imagine down. When comparing humans with animals, for example, we can imagine down by distinguishing things we humans can do that are beyond the capability of our animal neighbors. When is comes to imagining ETI who might be superior to us in intelligence, it is difficult to imagine up. It is difficult to imagine what superior intelligence could manifest that is beyond the very human intelligence that is doing the imagining. This puts initial constraints or limits on how we can begin to approach the topic of ethics when engaging ETI more advanced than earth’s homo sapiens. Nevertheless, it is incumbent in astro-bioethics to speculate about the possibility of engaging with intelligent beings who are superior to us.

If we meet ETI superior to ourselves, will they be hostile? Neutrally peaceful? or salvific? Given the assumptions made by many astrobiologists that extraterrestrial evolution will follow a path toward increased intelligence as it has on earth, the prospect of ETI fitting the hostile category is to be expected. Charles Darwin’s key evolutionary principle is “natural selection,” which he identifies with “the struggle for existence’ and with Herbert Spencer’s phrase, “survival of the fittest” (Darwin, 89). In the struggle for existence, living creatures undergo cruelty, suffering, and waste (Darwin, 445). And the species to which virtually every individual creature belongs will eventually go extinct to make way for a more fit species. The strong devour the weak. The big eat the small. The fit survive in a world that is, as Tennyson put it, blood “red in tooth and claw.”

Given astrobiological assumptions regarding a repeat of evolution on extraterrestrial planets, hostility is what we should expect on the part of ETI. Yet, surprisingly, some SETI speculators anticipate meeting intellectually superior ETI who will benevolently help us on earth. For this reason, I add the subcategory: salvific.

Now, how do we get from the struggle for existence to extraterrestrial saviors? How does evolution transcend itself?

Let’s look at the logic operative in this speculation. Some in the astrobiology community project an image of a more highly evolved extraterrestrial creature who would like to rescue us earthlings from the ignorant habits we have developed due to our inferior level of intelligence. Because we on earth have not yet achieved the level of rationality necessary to see that international war and planetary degradation are inescapably self-destructive, we could learn from ETI more advanced than we.

Such thinking is obviously myth, not science. No empirical evidence justifies such speculation. Yet, such dreaming of redemption descending from Earth’s skies is tantalizing to the terrestrial imagination. I have noted elsewhere that included in much of astrobiological theorizing is a version of the ETI Myth (Peters, 2008, chapter 3). The essence of the ETI myth is that science saves. Science can save earth from its inadequacies, its evolutionary backwardness, its propensity for self-destruction. If terrestrial science is insufficient, then extraterrestrial science just might be.

By myth here I refer to a cultural construct, a window frame, so to speak, through which we look in order to view the world out there. At work in modern culture in general, as well as in astrobiology in particular, is an identifiable framework - a myth, if you will--within which we cast the questions we pose to the mysteries evoked by our experience with outer space. The ETI myth reveals its shape as SETI’s Frank Drake gives voice to speculations: “Everything we know says there are other civilizations out there to be found. The discovery of such civilizations would enrich our civilization with valuable information about science, technology, and sociology. This information could directly improve our abilities to conserve and to deal with sociological problems - poverty for example. Cheap energy is another potential benefit of discovery, as are advancements in medicine” (Cited by Richards, 2003, 5). Note the optimism. Drake does not expect what Darwin or Hawking would expect, namely, an extraterrestrial race engaged in the struggle for existence which might like to exploit us on Earth. Rather, Drake’s extrapolation of evolution to ETI imagines an intelligent and benevolent race ready to offer us aid and assistance. His vision includes optimism regarding the solution to earth’s “sociological” problems such as poverty and energy. Space visitors might even give us a leap forward in medicine.

What Drake believes is that science is salvific; and extraterrestrial science would be even more salvific than terrestrial science. In sum, should an extraterrestrial civilization more evolutionarily advanced than we engage planet earth, we could benefit from the ability of ETI to save us from our own primitive inadequacies and even our own propensity for self-destruction. It is this thought structure within astrobiology that warrants the designation for more highly evolved and more intelligent ETI as “salvific.”

Suppose Drake’s prophecy gets fulfilled. Suppose ETI turn out to be salvific. In the event that ETI turn out to be not only more intelligent but also altruistic toward us, then an ethic of gratitude might be included in our responsibility. We would receive and make use of the gifts that increased intelligence would allegedly provide us: such as the means for maintaining a healthy planetary ecology, improvement in our medical care, and more justice in our social practices. Then, we would build upon what we have already said about maintaining terrestrial peace and treating our superiors with dignity; we would add a measure of grateful respect.

The alternative, of course, is that superior ETI might be hostile. If superior ETI follow Darwin and Hawking and confront us with hostile and exploitative enslavement, then perhaps we will frame our ethics accordingly. The New Testament provides instructions for slaves. NRS 1 Peter 2:18: “Slaves, accept the authority of your masters with all deference, not only those who are kind and gentle but also those who are harsh.” This may seem unrecognizable for us today. The treatment of the superior master by an inferior slave has fallen into disuse in our post-Enlightenment period. This is because of the erasure of the line between superior and inferior human beings within modern Enlightenment culture. We are all equal - that is, we all share the same moral status. Each of us has dignity by virtue of our belonging to the human race, and slavery violates the principle of dignity. Should a master-slave relationship rear its ugly head somewhere on our planet, we children of the Enlightenment would encourage the slaves to rebel and strive for their own liberation. Such a moral commitment to liberation would be justified by the assumption that both masters and slaves are not other but rather are equal.

When we use the assumptions made by many in the astrobiology field, however, we cannot coherently make the argument that all intelligent beings are equal. Those who have evolved longer and who have attained a higher level of rational intelligence would be, by definition, superior to us. We could not justify liberating ourselves from their rule with an argument based upon equality. Perhaps we are now getting a vision of the blind alley that we are led into when we make intelligence our primary criterion. When we tie dignity to rationality or intelligence - and when we find ETI more intelligent than we are - we hang ourselves on our own gallows. All that is left for us is a self-appointed slave ethic. I am not prescribing this with enthusiasm. Rather, I’m drawing out ethical speculations based upon widespread assumptions.

If intellectually superior ETI are not especially hostile nor altruistically motivated to be our saviors, then we might frame our ethical deliberation anticipating neutral peacefulness. In the event that either peer or superior ETI approach the civilizations on Earth in a peaceful manner, we would want to respond with working through just institutions. Maintaining peace would become an immediate moral commitment. We might even find ourselves organizing to quiet down and restrict earthly voices that would disturb the peace. We would want to police ourselves in the name of peace. Peace would benefit life on earth. In addition, moral policies we set would likely treat our new space friends with dignity, respect, and courtesy.

It is my own view that we should treat superior ETIs with dignity, respecting and even caring for their welfare. If they are hostile and enslave us, we should invoke an appropriate slave morality that maintains their dignity. If ETI are peaceful toward us and open up avenues of conversation and commerce, then the principles of justice and the striving to maintain peace should obtain. If out of their superior wisdom and altruistic motives ETI seek to better our life here on earth, we should accept the gifts they bring and respond with an attitude of gratitude.


In this exploratory and speculative essay, I have tried to spell out ethical scenarios based upon existing prevalent assumptions. Included in these assumptions are such things as progress in evolution, intelligence or rationality as the criterion for measuring human advance, attaching human dignity to human rational capacity, and giving top priority to protecting ourselves and our planet. In principle, however, one could pursue astroethics with a different set of assumptions. Regarding our most valued criterion for human achievement, one could imagine replacing advanced intelligence with transformatory love. Then, peace and mutual benevolence would become the moral goal rather than merely just institutions. To follow this path has not been my task here.

As we have seen, astroethics today is necessarily a speculative endeavor. The astrobiology upon which astroethics deliberates is itself speculative. When it comes to extraterrestrial intelligent life forms, terrestrial scientists are comfortable imaginatively exporting to alleged habitats in space the idea of a separate genesis of life and a story of evolution parallel to earth’s story. Evolution in this case is assumed to be progressive, following an entelechy toward increased rational intelligence. In the case where the length of evolutionary development is less than or comparable to our own, we can expect inferior or equal levels of rational capacity. In the possible case where an extraterrestrial race has had more time to evolve, we can expect a level of rational intelligence superior to our own. Speculation on the part of the astroethicist should be ready to construct a framework for moral responsibility that corresponds to these three relevant moral communities.

Teed Peters is Professor of Systematic Theology at Pacific Lutheran Theological Seminary and the Graduate Theological Union. Along with Robert John Russell, he co-edits the journal, Theology and Science, at the Center for Theology and the Natural Sciences. He is the author of The Evolution of Terrestrial and Extraterrestrial Life (Pandora Press, 2008) and co-author with Karen Lebacqz and Gaymon Bennett of Sacred Cells? Why Christians Should Support Stem Cell Research (Roman and Littlefield, 2008)

Along with Martinz Hewlett, he is co-author of Can You Believe in God and Evolution? (Abingdon, 2006).


Excerpted and Revised from a paper delivered in May 2008 at Biosphere 2 for the University of ArizonaR, College of Science Center for Astrobiology

In honor of Neville (Nick) J. Woolf

Ted Peters


[1]In order to prepare for life forms that might be very “other,” scientists at a new interdisciplinary research institute in Austria are working to uncover how life might evolve with “exotic” biochemistry and solvents, such as sulphuric acid instead of water. Science Daily Staff.