SETI, METI and the paradox of extraterrestrial life: is there a libertarian perspective?

1.0 Where Is Everybody?

Call it the Great Silence [1] or maybe the “Fermi Paradox.”[2] Despite early, optimistic forecasts that we would soon find signs of alien beings beyond Earth, five decades of SETI, the Search for Extraterrestrial Intelligence, have been fruitless. We are unaware of clear evidence for the existence of  aliens or their works.

Of course, that situation might change tomorrow. And yet, for now, the puzzle is both daunting and profound. Theories that attempt to explain the Great Silence – the absence of signals or observable artifacts – are sometimes called “fermis” for short. Some fermis are chillingly plausible; others seem just short of impossible. Each has been pushed, at one time or another, by someone (or many) with lots of ego invested: “this is why we haven’t met anyone yet!”  My role, for thirty years, has been to catalogue these hypotheses – more than a hundred, to date. They generally involve suppressing the estimated value of one or another factor in an expanded Drake Equation.

Those who have watched Cosmos or dozens of other science shows have at least seen it. Let N = the number of technological civilizations currently in the galaxy. Then,

N = R P n(e) f(1) f(i) f(c) L

Where R is the average rate of production of suitable stars, approximately one per year. P is the fraction of solitary stars that have planets (Recent science has allowed us to set that fraction at near one.) Other factors include n(e), the number of planets supporting liquid water and other life-ingredients, per suitable star; f(1), the fraction of these congenial planets on which life actually occurs; f(i), the fraction of these on which “intelligence” appears; f(c), the fraction of intelligent species that attain technological civilizations, and L, the average lifespan of each species.

In classic form, the Drake Equation doesn’t correlate with any observable. You must massage it, asking “what should we see?” It is also short several factors. A modified version [1] lets us estimate the number of technological species that ought to be currently visible to us. And, since we know of no aliens (so far), that output number must be set at one (representing lonely humanity) and the factors adjusted accordingly.

As Michael Hart,[3] then Jones and Finney[4] pointed out, this quandary grows more difficult if we accept the possibility of interstellar colonization – either by biological sapients or by self-replicating probes. So we add a factor for colonization-expansion speed V(i) (which some disputants set at zero). An expanded version must also include detectability cross sections, A(i), because many fermi hypotheses posit reasons why aliens might be difficult to notice. We also need L(i,c), the average duration/lifetime of each colonized site.

As Michael Michaud put it in Contact With Alien Civilizations: “[Dr. Frank] Drake admitted that the negative results… do imply that there are no large numbers of civilizations transmitting at many frequencies, at least not lately.” Something has kept the prevalence and visibility of ETCs below our threshold of observation.[5]

Another term for this is the “Great Filter.”[6] Some effect that spans galactic distances appears to be filtering the number of observable, advanced ETCs down to a level where their failure to be noticed can be explained away with the common saying among SETI folk: “Be patient. We just haven’t found them yet.”

1.1 Picking apart the likely “Fermi” explanations.  

“Uniqueness” proponents – stretching from Hart to Ward and Brownlee [7]  – tend to pick one or another of the factors on the left side of the Drake Equation to suppress. These are factors having to do with the origination of species like ourselves. For example: stable planets with liquid water on the surface may be rare, or such worlds may develop life with less alacrity than apparently happened on Earth, or other living worlds may experience catastrophes at much higher rates. We live in a golden age for studying these factors.

Even more interesting is the emotional driver in the Uniqueness Camp – a desire to believe that whatever is suppressing the numbers must lie behind us. “The Great Filter” that keeps Galactic ETCs rare or unobservable is something unique about the path that brought us here, and therefore we can now look ahead to a pitfall-free destiny, filling a mostly-empty cosmos with our descendants. Those who at first appeared pessimistic are – for the most part – sunny and cheerful fellows.

1.2 Right-Handed Explanations 

The opposite effect can be seen in members of the classic SETI community. Clinging to the original estimates of Carl Sagan and others, for high values of f(l), f(i), f(c) etc., they want to believe that life and intelligence and emergent tech-ETCs are abundant. But that leaves them with a Great Silence to explain. And they do that by suppressing factors on the right side of the Drake Equation.

For example, Sagan famously posited that humanity must grow up or else annihilate itself via nuclear winter. One could always update that failure mode: nanotech plagues, runaway synthetic biology, rebellious AI, take your pick. He generalized that all those other species out there who passed through a similar phase, and who did not cure themselves of aggressive tendencies, would wipe themselves out. Sagan’s political and moral motives were clear, but this approach also provided a filter to reduce Drake Equation outputs.

By picking variables on the right side of the equation, such as the average lifespan of newly fledged techno-species, or their speed of aggressive expansion, SETI optimists could model a level of sparseness of detectable ETCs to match any cosmic haystack result and still say: “any day now we’ll find ‘em.” Ironically, by presuming that ETC numbers are winnowed by death and failure, and by the difficulty of travel and colonization, it would seem that the “optimists” in SETI are not as sunny of disposition as many in the uniqueness crowd.


2.0 METI: Meddling in the Experiment

One must feel sympathy for SETI-ists. They have devoted lifetimes to a project that always drew ridicule from one side and fervent fandom from the other, not a situation conducive to detachment. SETI is forever plagued by financial problems, depending upon unpredictable spates of largesse from donors such as billionaire Paul Allen, or upon infrastructural support from hard-pressed universities.

Even as new, SETI-specific telescopes and sophisticated signal processing systems come on line, there is another pressure – the beating of time. Each better instrumentality sifts the cosmic haystack for the proverbial needle ten or a hundred times better than the ones that came before it. Great! But the refrain “any day now” starts to ring hollow and the ongoing silence grows frustrating, even daunting.

Under those conditions, it is perhaps understandable that a temptation would grow to poke at the experiment. If ET is keeping quiet, then should we be the ones to speak up? To shout into the cosmos? To cry “Yoohoo!” and provoke the conversation into being? To send Messages to Extra-Terrestrial Intelligences, or engage in METI?

While some in the community of radio astronomers have drifted toward a scientific sin – poking-at-the-experiment – others (including this writer) have objected to this new, untidy, and presumptuously tendentious endeavor. [Author’s note: an expanded version of this paper, referenced below, explores the “fermis” and background of METI in more detail.]

2.1 The SETI Protocols.

During the early nineties, a sober effort was made to develop guidelines for any First Contact event – resulting in the First and Second SETI Protocols. These set down:

(1) what principles should guide astronomers and other participants amid the hectic period during and following an actual SETI “hit.”

(2) whether, how, and when to transmit de novo messages – wholly of our own volition – far more obtrusive than the 1974 Arecibo signal.

I served along with chairman Michael Michaud (a retired senior U.S. diplomat) and former NASA SETI director John Billingham, on the committee assigned to draft these documents. The First Protocol (concerning behavior in the event of a verified SETI detection) has been adopted as a guideline by most of the scholarly communities that turn big radio telescopes skyward. It is widely accepted as a consensus agreement on best practices. [11-12].

The First Protocol contains an injunction against anyone peremptorily responding to a discovered alien signal, before appropriate international consultations have taken place. And, while that loose term is left undefined, any sensible adult would recognize what the clause means. That no one should impudently arrogate a right to speak for all of humanity – or initiate a first contact event that could have major repercussions upon billions of other people – before there has been at least a serious attempt to pose the matter for discussion before as many of humanity’s brightest intellects as practical, from a wide range of relevant disciplines, holding a very public conversation about what to do next.

All of these imperatives are still deeply believed by the “dissidents” in the SETI community who object to METI, who included Billingham, Michaud, and this author, who resigned from SETI-related committees and commissions in protest over what we deem to be the precipitate, unscientific and unprofessional behavior.

Alas, in recent years there has been a fad to “beam messages at ET” – everything from rock n’ roll to Doritos ads, rather unlikely to reach their targets… plus some far more serious attempts using planetary radar beams at Arecibo and the Evpatoria dish in the Crimea. In not a single case was the spirit or letter of the SETI Protocols followed, allowing a public conversation and reciprocal argument to penetrate the rationalizations of those who would eagerly alter human destiny, blithe in their assumptions about the nature of unknown alien societies, assuring us all “Don’t worry. We have it under control.” 

2.2    The overwhelming urge to meddle

One complaint about METI is that if everyone else out there is being quiet, maybe it’s because they know something we don’t know. The notion that we should make assumptions about a benign cosmos and start hollering, when others who are presumably older, wiser, and vastly more powerful are evidently refraining… this would seem preposterous and at least face a steep burden of proof.

Alexander Zaitsev – one of those who have performed METI “experiments” using powerful planetary radar dishes – crafted a response to this assertion, one that while perhaps weird has the virtue of originality. He says that any nearby ETCs are perforce – by reason of their silence – cowards who must be coaxed into opening up. Zaitsev even suggests a new Drake Equation factor f(m) for the low fraction of technological species who have a “clear and non-paranoid consciousness sufficiently courageous to engage in deliberate interstellar transmissions,” and thus he concludes that we, as the new (and presumably courageous) kids on the block, are behooved to do the coaxing [13-14].

Ironic juxtapositions abound. During the USSR era, Soviet dogma insisted that any advanced ETC would automatically be both altruistic and socialist. Since then, Russian and European SETI-ists have dropped the “socialist” portion, while retaining belief in automatic harmlessness on the part of any advanced race. Although reconciling altruistic with cowardly and paranoid may seem awkward to some, it appears to have been no problem for Zaitsev. Indeed, let me avow that it is conceivable that we, as the descendants of gregarious-omnivorous apes, might indeed possess some traits of personality that make us inherently more outgoing than average. More on that later.

This is just one of many hypotheses and counter-arguments that have spilled back and forth. Indeed, the only unfortunate thing is that the debate has taken place in such tight clusters, instead of the broad, eclectic and internationally public discussions that such a topic deserves, and that would doubtless fascinate tens of millions.

This is not the place for a complete “j’accuse” indictment against METI and its fellow travelers. We dissidents have laid out our case of objections elsewhere. My own public protest, perhaps the most colorful [15-16], followed years in which – successively – each of us grew frustrated with secretive and arrogant practices.[17]

It appears to us dissenters that the psychology behind this shift is frustration. It happens to all scientists, now and then, when the experiment obstinately refuses to comply with  passionately yearned-for results. The temptation to meddle, to poke, to prod and holler is understandable, even if giving in to it is unforgivable. Especially in the manner that it has taken place in SETI.

As citizens of an emerging worldwide, technological civilization, we have begun coming to terms with a valuable new branch of science called Risk Analysis. While our power as a species increases, we keep uncovering ways that both nature and our own actions might bring grief, death, and destruction. The history of our planet is riddled with extinctions and/or first-contact disasters. We can now see that Carl Sagan was right in one respect – that a new and rash sapient race is capable of meting calamity upon itself or the planet that nurtured it. This dreadful realization of our power should not daunt us from moving forward! But it behooves us to study the methods of foresight, anticipation, and maturity, weighing plausible risks and ranking them along a scale that takes into account both their estimated probabilities and the potential severity of their outcomes.

Some METI supporters interpret our call for substantial, eclectic, broadly inclusive prior consultations before METI as an effort to muzzle our planet forever. Dr. Seth Shostak has asserted that such consultations can only have one outcome, permanent repression of free enquiry in an important field of science. He stated: “Even if the odds of a devastating reaction are long, those consequences could be lethal, and therefore there is no acceptable level of risk.” Whereupon he concludes that any such open discussion would inherently be disposed to extend a METI moratorium forever.

This strikes home in personal ways. My own nonfiction exploration of transparency, openness, and accountability – The Transparent Society: Will Technology Make Us Choose Between Privacy and Freedom? – won the Freedom of Speech Award of the American Library Association for promoting open discourse as a fundamental element of our social and technological compact. I note this only to show that I am deeply aware of the scenario that Dr. Shostak has raised. 

To be clear, the scientific rigor mortis that he describes is certainly a danger to be considered and countered, if we are to move forward. (It is also major topic in my novel Existence.) But many fields have already begun adapting ways to meet this challenge, blending reasonable caution and responsibility with determination not to let science be imprisoned by fear. For example the genetic sciences held a moratorium for risk study in the 1990s – the “Asilomar Process” – that resulted in dozens of new and universally adopted safety procedures that made us all far more secure… and that scientific groups swiftly got used to – measures that wound up impeding science hardly an iota.

SETI should do likewise. What is certain is that refusal to discuss the matter in broad exchanges, involving the widest array of specialties plus the public, is the surest sign of intellectual dishonesty, even cowardice.


3.0 A libertarian perspective

Many aspects of the SETI/METI debate bear on our personal beliefs about the nature of intelligent beings, including their rights, obligations, and potentials in the context of a much, much larger scope of space and time. 

For example, would our favorite models of “human nature,” including the importance of individuality, apply equally to a sapient race descended – say – from pack carnivores, like wolves? Or solitary hunters, like tigers? Or solipsistic omnivores (bears), or herd herbivores? Or ants?

Even among the heirs of omnivorous, gregarious apes, we humans have come in a wide variety of types and organized ourselves in colorfully different societies… though some patterns seem to have persisted. For example, a vast majority of human groups that achieved agriculture and metals quickly organized themselves into pyramid-shaped hierarchies, in which narrow clades of noble-owners and priests lorded it over ignorant and impoverished masses below. Moreover, those ruling classes made it their top priority to preserve dominance, suppressing merit competition and mobility, ensuring that status would be inherited. The Darwinian selection drivers behind this trend are obvious. Any gang who picked up swords might get to steal other men’s women and wheat, ensuring their own reproductive success. We are all descended from the harems that those successful bandit-aristocrats collected – and the harems that their sons employed, unearned by any effort, accomplishment, or merit.

Is feudalism the “natural” social order? Among cultures that were not hunter-gatherers, it certainly dominated over virtually all of historical time, and probably it was fiercely practiced before that. It appears to be a self-reinforcing “attractor state” in which technology (e.g. metal weaponry) empowers any cabal of the strong to exert power over large numbers of their peers. The same underlying pattern appeared in kingdoms, theocracies or Soviet commissar castes. Hence: is the feudal pyramid obligate and permanent? Are we, perhaps, only living through a brief exception to a pervasive pattern? More generally, might the same Darwinian attractor apply elsewhere across the galaxy, wherever intelligence arises?

Ubiquitous feudalism could indeed cripple many a promising species. Certainly, if one looks at pyramid-shaped societies on Earth, it appears that the lords’ reproductive success was purchased at the price of scientific stagnation, rigid repression, and miserably awful statecraft. If so, then we have a plausible and compelling “fermi” or hypothesis for the absence of ETCs: the feudal attractor state is so successful that most species fall into an endless condition of stultified stagnation. Fearful of destabilizing effects, ruling castes never allow spaceflight, let alone exploration - by radio or in person – of the stars.

Fortunately, this classic social pyramid, while by far the most common human pattern, is not the only one. Across the last two centuries we have experimented with a different attractor model – one that is diamond-shaped, with an empowered middle that both outnumbers the poor and is unafraid of the rich. In the Enlightenment Experiment, arenas like markets, democracy, science, courts, and sports successfully harness regulated competitiveness to create tsunamis of wealth and free exploration, while also allowing and encouraging countless opportunities for willing cooperation. The resulting society roils and froths. It may seem chaotic, especially for those who dream of simple, perfect utopias. But inarguably it has outperformed – in just two centuries – all of the preceding feudal pyramids… combined.

The advantages of this experimental process – unleashed human creativity, social mobility and industrious fecundity – come with one major drawback: the diamond pattern is inherently unstable. In every generation, fresh waves of cheaters attempt to compress or manipulate the diamond back into the shape of a classic pyramid. These pressures are never absent, though their surface excuses shift with astonishing incantatory agility.

Indeed, failure to grapple with the implications of this perpetual threat to competitive creativity is perhaps the greatest flaw in modern libertarianism. Anyone who claims that competitive arenas can remain effective without carefully negotiated regulation to suppress cheating should try this experiment: set up a sports league without rules, in which the strongest players are free to unite in a single team, if they so choose. (To make the experiment perfect, establish it without even laws against violence and murder: think Rollerball.) Now generalize that approach to all realms of human endeavor and recognize it as the pervasive pattern of all human history.

When the strong can side with the strong against the less-strong, you quickly get cartels and monopolies, then inherited ruling castes, and the old cycle is re-established. It is being attempted as we speak. What emerges is a primary truth about our vastly productive, competitive, wealth and freedom-generating arenas – markets, democracy, science and so on – that they are not “natural” but instead carefully and brilliantly designed machines, built in order to overcome what is natural – the human propensity for cheating.

This notion is not new. Adam Smith’s version of libertarianism has always aimed to maximize competitive output by keeping power dispersed while fostering new competitors from below. It is a pragmatic, engineering approach to encouraging competition, contrasting sharply, I would argue, against the more recent, quasi-religious version of libertarian ethos – one that declares all regulation inherently and automatically evil and that “market laws are laws of nature.” Tell that to the would-be entrepreneurs who were repressed in Imperial China, or ancient Rome, or Persia, Meso-America or almost any other pyramid of power in humanity’s stifled past. 

3.1  Libertarian implications of the Great Silence. 

These implications are profound and worrisome. If humans can (with great struggle) just barely keep going this alternative attractor state – the vibrant and churning diamond-shaped social pattern, with its arenas of regulated competition – then what are the odds that it has successfully emerged elsewhere, across the galaxy, where sapience did not arise out of gregarious-egalitarian apes?

Sure, pyramids and diamonds are not the only two possible types of societies, even on Earth, and many others may flourish out there, across the galaxy. Indeed, we Earthlings may try others – though if they are freely competitive-cooperative, then they will be subsets of the diamond.

In fact, this hypothesis – that alien races might also be trapped by a cultural attractor state of feudal stagnation – is only one of what I deem to be the “top ten” hypotheses for the Fermi Paradox. Others loom just as high… and are discussed elsewhere.

Suffice it to conclude – for this article, in this community of discussion – that we need a wider perspective than we are ever shown by Rand or Rothbard or Marx… or even Adam Smith. Simplistic and formulaic dogmas may be personally satisfying – they let us dismiss our political opponents as 100% wrong, instead of the mere 90% that might offer us some food for thought and room for negotiation. But in fact, such sanctimoniously satisfying purity is an impairment when you take in a larger picture. We are, after all, barely above cavemen, feeling our way out of a chasm of ignorance. What are the odds that you, right now, are the acme of all understanding, whose incantations are perfectly better than the incantations that were fervently believed by followers of Thoth, or Baal… or Keynes or Hayek?

We are only likely to make it if we exhibit – constantly – the agility and willingness to re-evaluate that are hallmarks of our band of clever, gregarious apes. That is, when we are at our best.  Simplistic dogmas are for insects. Only if we deal with complexity will we gain access to those baubles overhead that we’ve started to relish, with rising eagerness and ambitious greed.

The stars.


4.0 Resources

An earlier version of this article was first prepared for a debate at the Royal Society in 2010. A longer version, with treatment of other possible “fermis,” was compiled for the Journal of the British Interplanetary Soc. Vol 67, No 01 (January 2014).

Professor Steven Dick’s Life on Other Worlds: The 20th-Century Extraterrestrial Life Debate (Cambridge University Press 2001) covers much of the history of these concepts during the latest human lifetime. For a tour of the concepts going back in time, see M.J. Crowe’s The Extraterrestrial Life Debate, 1750-1900: The Idea of a Plurality of Worlds fro Kant to Lowell (Cambridge University Press 1986). Another book that covers the general field is Contact With Alien Civilizations (Copernicus Books, 2007), by former senior U.S. diplomat Michael Michaud.

Extraterrestrial Civilizations, edited by Thomas B.H. Kuiper and David Brin, (American Association of Physics Teachers, 1989) is a reprint book that offers some of the classic papers in the field ranging from SETI enthusiasts like Sagan, Drake Cocconi and Morrison to early uniqueness proponents (e.g. Hart) and appraisals of interstellar travel and migration by Forward, Finney and Jones and by Oliver.



1. Brin, G.D., “The Great Silence - the Controversy Concerning Extraterrestrial Intelligent Life” Brin, G.D., Quarterly Journal of Royal Astronomical Society, fall 1983, v.24, pp283-309.

2. Wesson, Paul, “Cosmology, extraterrestrial intelligence, and a resolution of the Fermi-Hart paradox,” Royal Astronomical Society, Quarterly Journal 31: 161– 170, 1990.

3. Hart, M., “An Explanation for the Absence of Extraterrestrials on Earth”, Royal Astronomical Society, Quarterly Journal, 16, 128-135, 1975.

4. Finney, B.R. and Jones, E.M., 1985 Fermi’s Questions, University of California Press, 1985.

5. Kuiper, T. & Brin, G.D. Extraterrestrial Civilizations, 1989 American Association of Physics Teachers.

6. Hanson, R. 1998 “The Great Filter, Are We Almost Past It?

7. Ward, P. & Brownlee, D., Rare Earth: Why Complex Life is Uncommon in the Universe, Springer 2003.

8. Benford, G., Benford J. & Benford D., “Searching for Cost Optimized Interstellar Beacon”, Astrobiology, 10 4, 490-498, 2010.

9. Brin, G.D., “An Open Letter to Alien Lurkers,”  1996.

10. Brin, G. D., Existence, Tor Books 2012.

11. Billingham, J., “A Decision Process for Examining the Possibility of Sending Communications to Extraterrestrial Civilizations,” 1996.

12. Brin, G.D., “SETI: A collection of introductions,” 2004.

13. Zaitsev, A., “Sending and Searching for Interstellar Messages,” Acta Astronautica 63, 614-617, 2007.

14. Zaitsev, A, “The Drake Equation: Adding a METI Factor” by Dr. Alexander Zaitsev, 2005.

15. Brin, G.D., “A Contrarian Perspective on Altruism: The Dangers of First Contact,” in Searching for Extraterrestrial Intelligence, Paul Shuch ed., pp 429-449 2011.

16. Oakley, B. 2012. Pathological Altruism, Oxford University Press, USA 23. Brin, G.D., “Shouting at the Cosmos,” 2006.

17. Michaud, M. “Ten Decisions that could Shake the World” Space Policy 19, pp.131-136, 2003.


Also from this issue

Lead Essay

  • David Brin criticizes the possibly reckless turn in recent SETI research. He also speculates on what the great silence may say about human societies. It may not be such a good idea to go about shouting to the cosmos - not when we have so little idea of what may be out there.

    That said, Brin speculates on the nature of any intelligent life we are likely to meet. He notes that our scientific and technological society is very unusual when compared to societies of the past: It is, he says, diamond-shaped, with relatively few at either the bottom or the top, and with a broad equality of social station, rights, and even wealth in the middle. Maintaining such a society is hard work, and one reason we seem to be alone in the universe may simply be that very few alien civilizations have escaped from feudalism or something like it.

Response Essays

  • Robin Hanson runs a cost-benefit analysis on our use of very loud radar signals. He finds that if there is even a small probability of a hostile civilization hearing us, then the risks are not worth the rewards. This conclusion holds up under fairly severe assumptions, and it grows much firmer as we consider our likely technological developments in the near future. Astronomy, moreover, is advancing rapidly, and it will likely tell us much more about the probability of existence and the nature of extraterrestrial life. When it does, we may have a better idea of the wisdom of sending out very loud radio signals. In the meantime, he concludes that yes, humanity should indeed shut the hell up.

  • We have few tools at our disposal to learn about intelligent extraterrestrials - if they even exist. But one relatively powerful tool is evolutionary psychology. Jerome H. Barkow reviews some findings from terrestrial evolutionary psychology and considers their implications for alien life. We will learn a lot if we can discover what aliens find sexy, he claims - because sexual selection has overwhelmingly influenced terrestrial animals, including ourselves.

    We will also learn a great deal by observing aliens’ predation history, their group cooperation, and their genetic transmission of culturally favored traits. Of course, these observations will have to wait for first contact. Barkow concludes by agreeing with Robin Hanson - until we know more, humanity should probably keep relatively quiet.

  • Douglas Vakoch argues that active SETI is not to be feared: If highly advanced civilizations exist out there, they will have highly advanced radio detection equipment. If they are anywhere near us, then they will have known about us for decades. Messaging them can do no more harm than what we have already done, and it may do us a great deal of good, particularly if these civilizations are waiting for us to make the first move, and if messaging them directly is the signal they need to initiate contact.