Non-Human Intelligence
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UAPs and Non-Human Intelligence: What Is the Most Reasonable Scenario?

Allow me to start with a confession: although the topic of UAPs (Unidentified Aerial Phenomena, previously called UFOs) has always fascinated me, my reaction to confronting much of the related literature—beyond the safe harbour of a few serious authors—has been one of considered dismissiveness. In my view, a significant portion of the published material could benefit from greater rigor, empirical grounding, theoretical clarity, and logical reasoning. This field often appears to diverge from the standards of intellectual precision and level-headed analysis that hold in academia. However, recent developments over the past six or seven years invite us to re-examine the subject from a more open and inquisitive perspective.

Because there are so few—if any—consensus launchpads for such a polemical topic, I must explicitly justify each step of my thinking and, thus, cover a lot of ground in this long essay. I shall start, below, by motivating the validity of the mystery: UAPs are no longer just tall and questionable tales shared on social media, accompanied by grainy, out-of-focus cellular phone footage. Enough has been officially acknowledged since 2017 that the topic is now undoubtedly deserving of serious treatment. After laying foundations for my argument, I will then proceed to elaborate on what I currently consider to be the most level-headed and plausible account of the phenomenon. And to anticipate a question you are bound to be already asking, no, I don’t think it is aliens from Zeta Reticuli; the facts may be a lot more surprising and closer to home than that.


In 2017, several videos of UAPs—soon to become known as the ‘Pentagon UFO videos,’ as they were recorded by infrared cameras in military aircraft—were circulating widely on the Internet. At around the same time, the story behind the videos was covered in a now-seminal report by The New York Times.

The videos seem to show airborne craft without wings or engines, flying and hovering deliberately, sometimes against high winds. They perform maneuvers despite the absence of flight control means—no rudder, elevators, ailerons, thrusters, etc.—and display surprisingly high acceleration with no detectable means of propulsion. The US Department of Defense later officially acknowledged the authenticity of the videos, as well as the fact that the objects visible in them remain unidentified.

Years later, in the summer of 2023, US Navy pilots involved in these incidents provided public testimony to Congress, under oath, adding detail and background to the odd images. Asked whether the UAP he saw with his own eyes moved in a way that defied the laws of physics, Commander David Fravor replied: “The way we understand them [i.e., the laws of physics], yes.” He then confirmed that the UAPs were not only captured on camera, but also tracked by radar from three different vessels: “The Princeton tracked it. The Nimitz tracked it. The E2 tracked it.” Asked to describe how the UAP maneuvered, CDR Fravor said, “Abruptly, very determinant. It knew exactly what it was doing. It was aware of our presence and it had acceleration rates—I mean, it went from zero to matching our speed in no time at all.” Finally, asked if any human technology could emulate the UAP’s flight characteristics he observed, he said: “No, not even close.” Navy F-18 pilot Ryan Graves—another military witness giving sworn testimony—described a UAP sighted from 50 feet away as “A dark gray or a black cube inside of a clear sphere,” something that cannot be conflated with a drone or ordinary aircraft.

Still in 2023, United States Air Force officer and former intelligence official David Grusch became a UAP whistleblower. In interviews with various media outlets, he claimed that several defense officials had confirmed to him that the US government maintains a secretive UAP crash-retrieval and reverse-engineering program, and is in the possession of several technological craft with Non-Human Intelligence (NHI) provenance.

Mr. Grusch, too, provided sworn testimony during the congressional UAP hearing of July 2023. Asked whether the US has the bodies of the pilots of the recovered UAPs, he said: “As I have stated publicly already … biologics came with some of these recoveries.” Pressed on whether these “biologics” were nonhuman, he confirmed without ambiguity: “Nonhuman, and that was the assessment of people with direct knowledge on the program I talked to that are currently still on the program.” Mr. Grusch understands that the penalty for lying under oath is jail, and offered several times during his testimony to confidentially—as required by law—provide specific details to lawmakers.

Mr. Grusch, Mr. Graves, and CDR Fravor are far from alone. In recent times, other individuals in a position to plausibly be privy to what the US government knows about the subject have come forward. For instance, oceanographer and retired US Navy Rear Admiral Timothy Cole Gallaudet has acknowledged having seen footage of UAPs while on active duty. Some of these UAPs have displayed the capability to go underwater (the so-called ‘transmedium’ capability described often in UAP reports). He has also expressed his belief that Mr. Grusch’s claims are true. Recently retired US Army Colonel Karl E. Nell—currently an aerospace executive—along with Christopher Mellon, who spent nearly twenty years in the US Intelligence Community and served as the Deputy Assistant Secretary of Defense for Intelligence, have lent credibility to the claim that there are active UAP crash-retrieval and reverse-engineering programs. Defense Intelligence Agency Programme Manager Dr. James T. Lacatski did the same, in a book officially cleared for publication by the Defense Office of Prepublication and Security Review of the US Department of Defense.

Up until 2017, the profitable UAP rumor mill was fed mainly by ‘anonymous sources,’ filmed with their faces and voices concealed, and telling vague stories largely impossible to verify independently. Even when one of those anonymous sources eventually identified himself—Mr. Robert Lazar—his credentials and even college education could never be verified. This has changed now: the names and credentials of the individuals mentioned above are not in doubt; they are who they say they are. And their ranks and roles put them in a position to plausibly know what they claim to know. These individuals are willing to testify under oath in public hearings and confidentially provide evidence to members of Congress. All this, while not proving that UAPs are of exotic origin, does lend credibility to UAP speculation. 

Even the former head of the All-domain Anomaly Resolution Office of the US Department of Defense—Dr. Sean Kirkpatrick, a man widely reviled in the UAP community as a prejudiced gatekeeper working against UAP disclosure—has made very consequential revelations during an official NASA press briefing: there are seemingly metallic spheres out there that, somehow, move and maneuver without any signs of propulsion or flight control surfaces. He proceeded to show a declassified video of one such a sphere, as recorded by an MQ-9 ‘Reaper’ military drone, one of the most sophisticated sensor platforms in the world today. The sphere shown moves fast, in a controlled, non-ballistic trajectory. Dr. Kirkpatrick then stated that this is just “a typical example of the thing we see most of; we see these all over the world.” That the spheres are described as making “very interesting apparent maneuvers” is significant, as it rules out balloons and ordinary drones. That they are seen frequently and all over the world also rules out elaborate, expensive hoaxes.

Prejudiced gatekeeper or not, Dr. Kirkpatrick has thus officially acknowledged that there are concrete UAPs “all over the world,” for which there is no prosaic account thus far. They have been recorded by a variety of military-grade sensors, not just cell phones. That Dr. Kirkpatrick’s revelations have not become headline news in every mainstream media platform across the world is emblematic of the apathy and cynicism—the ‘don’t-look-up syndrome’—that has been assailing Western societies in recent years.


As a culture, we’ve thus reached an impasse. On the one hand, the meager amount of data that has been declassified or leaked isn’t enough for us to derive any firm conclusions regarding the nature of the phenomenon. On the other hand, enough has been begrudgingly but officially acknowledged that we can’t dismiss the phenomenon under prosaic accounts either. The best we can do is thus to take the data seriously, but not extrapolate from it without basis.

In this spirit, I submit to you that the following tentative premises are justifiable: firstly, there is an engineered technology in our skies and oceans that is not human. The counterargument to this is, of course, that UAPs may be top-secret but very human military devices, often called ‘black technology.’ Yet, this seems to contradict much of what has been disclosed since 2017. The following passage from the testimony of CDR Fravor to Congress illustrates the point: Representative Ms. Nancy Mace asked, “Many dismiss UAP reports as classified weapons testing by our own government. But in your experience as a pilot does our government typically test advanced weapons systems right next to multimillion-dollar jets without informing our pilots?” To which CDR Fravor responded: “No. We have test ranges for that.”

Moreover, if UAPs such as the metallic spheres were black technology the US Department of Defense were trying to keep secret, it is hard to imagine why Dr. Kirkpatrick—an official of that very department—would publicize their existence and even declassify a video showcasing their size, form, flight capabilities, etc. Also, the fact that UAPs often seem to defy our understanding of physics doesn’t line up with the black-technologies hypothesis, as it would require not only the engineering to be secret, but also the very advancement of the human understanding of physics. This isn’t impossible, but isn’t very plausible either. Finally, it is difficult to imagine why such game-changing black technologies—which would have to have been around for at least as long as the UAP phenomenon itself—were never used in large and conspicuous scales to advance the geopolitical interests of any nation.

Secondly, if there is non-human technology in our skies and oceans, then there must be Non-Human Intelligences (NHIs) active on our planet, engineering and controlling the UAPs. This does not imply that the NHIs are extra-terrestrial; it means simply that they aren’t human.

As implausible as these two premises may sound in this particular historical junction, the data, if taken seriously, does not seem to allow for prosaic alternatives. So whatever hypotheses we entertain, they will perforce stretch our credulity. Indeed, to insist on prosaic explanations we must disregard the data. The latter is not necessarily invalid—it isn’t incoherent to imagine that all the data are the spurious fabrications of some sprawling disinformation campaign stretching over decades—but it certainly doesn’t advance the discussion. It thus seems more productive, at this point, to bite the bullet of what the data suggests—at least hypothetically—and then check whether we can make sense of it in a manner that renders the data less vexing.

Before we can try that, however, we first need to understand the key characteristics of the phenomenon we are trying to account for.


Although the disclosure process is relatively young, having publicly started only in 2017, the phenomenon itself seems to be at least as old as humanity. Ancient mythology, religious and otherwise, contains narratives largely consistent with today’s UAP observations. And serious researchers—the most prominent, competent, and reliable of which, in my view, is French astronomer and computer scientist Dr. Jacques Vallée—have been collecting data on it, applying statistical analyses to such data, and deriving conclusions from such analyses for decades now.

Two key conclusions from Dr. Vallée’s work are particularly pertinent to our challenge here. The first is that, based on countless witness reports, the phenomenon does not seem to make any distinction between physical and psychological effects; it produces both, as if they were mere facets of one and the same causative mechanisms. The boundaries we draw between the mental and the physical don’t seem to be observed by the phenomenon, which transits casually back and forth across the dividing line. Dr. Vallée acknowledges the undeniable physical aspect of the phenomenon—it can be filmed, tracked by radar and other sensors, emits measurable energy, often leaves physical footprints and vestiges behind, etc.—but adds that at least part of what the witnesses experience is “staged”: the UAP sometimes evokes archetypal, symbolic imagery directly in the witness’ mind to convey a feeling-laden metaphorical message, which transcends the objectively measurable characteristics of the phenomenon.

Though Dr. Vallée had already come to this conclusion decades ago, recent investigations into secret US Department of Defense programs on UAPs, by journalist Ross Coulthart, seem to confirm it (see pages 265-267 of Mr. Coulthart’s 2021 book, In Plain Sight). Stanford Professor Dr. Garry Nolan, perhaps the most respectable scientist to actively research the phenomenon, acknowledged Mr. Coulthart’s reporting on the matter. He went on to recount a specific UAP case that illustrates, perhaps better than any other, the UAPs’ ability to directly manipulate human perception: “[this is a] story that Jacques Vallée brought to me, of a family in France, driving down the highway. This was like in the last five or ten years [from June of 2022]. And they had a glass-topped car. They look up and they see a UFO, you know, basically paralleling them down the highway. The mother looks around and sees that no other individuals nearby are freaking out about this thing above them. The children in the back take out their cell phones, take a picture of it. They get home and they look at the pictures on their camera, and they don’t see an object [of the kind they thought they had witnessed]; they see a little star-shaped thing about thirty or so feet above, and I have the picture. That doesn’t look anything like a drone. … I think it has like seven spokes and a central hole of some sort. So, you’re left with this: they saw a giant craft, but the picture shows that it was nothing [like it] there. Nobody else could see it. So, even if it was an object that was there, others weren’t capable of seeing it, so it was manipulating vision” (my emphasis).

The second pertinent conclusion from Dr. Vallée’s work is that the pattern of behavior of UAPs is not consistent with the extra-terrestrial hypothesis (see chapter 9 of his book, Dimensions). Dr. Vallée estimated that, in a period of just twenty years, there have been about three million UAP landings. This is not consistent with visitations by beings from another planet for the purposes of surveying the Earth or researching its inhabitants (orders of magnitude fewer visits would have sufficed for these purposes); instead, the UAPs’ behavior is precisely what one would expect if they were from here—and were simply going about their business. After all, there are many rare—and some not-so-rare—animal and plant species that human beings encounter a lot less frequently than 150.000 times per year, and they are undeniably terrestrial. In his interview with Mr. Coulthart, also Dr. Nolan expressed the view that UAPs are not extra-terrestrial.


Although the two characteristics discussed above generally apply to most of what we colloquially label ‘UAP,’ ‘UFO,’ or ‘alien’ encounters, there are reasons to entertain the possibility that we are dealing with at least two distinct phenomena here. If so, it is crucial that we do not conflate the two, otherwise, any viable account of one phenomenon may be discarded merely because it is not suitable for—or even contradicts—the other, leading to an insoluble impasse.

One clearly discernible class of observations, which I shall henceforth refer to as ‘nuts-and-bolts’ UAPs, entails physical craft that can not only consistently be seen, filmed, and tracked by radar, but also—if we are to believe Mr. Grusch’s informants and other sources in a position to plausibly know—stored in hangars for decades, drilled into, analyzed under a scanning electron microscope, etc. The bodies of their occupants can also—again, if we are to believe the sources—be kept in freezers and harvested for biochemical analysis. This means that the phenomenon in question has a physical aspect as consistent and stable as our own body and the car in our garage. Moreover, these ‘nuts-and-bolts’ UAPs are more frequently observed in the proximity of military exercises and installations, particularly nuclear installations (this has been the case for decades, the recent Pentagon UFO videos simply reiterating the pattern). They don’t seem to be interested in teaching us anything, but simply in monitoring human activity that could lead to large-scale destruction and compromise the planet’s habitability (incidentally, this is exactly what one would expect if the NHI in question is terrestrial).

Unlike the above, another class of observations entails encounters in one’s bedroom, at school, during one’s commute back from work, and other ordinary, random situations unrelated to military activity. These are the so-called ‘high strangeness’ events, encompassing the ‘alien contactee’ and ‘alien abduction’ cases. The craft and beings observed don’t have a consistent physical aspect but are, instead, elusive, appearing and disappearing, taking on an absurd variety of incongruous forms and behaviors. They leave either none or scarce, ambiguous physical traces, such as spontaneous nose bleeds, ordinary cysts found in places where the witness claims to have been implanted with alien technology, marks on the ground consistent with a variety of causes, and so on. This ambiguous physical evidence is better described as synchronistic—i.e., coincidental in a meaningful way—as opposed to causal. The observations are elusive, illogical, and shapeshifting like a dream. They seem focused on a form of deliberate, symbolic communication with the witness, aimed at conveying a teaching of some kind, as opposed to arising from chance encounters. Like a vision, they can’t be photographed.

I am not dismissive of this ‘high strangeness’ class of observations. As a matter of fact, I have written an entire book—Meaning in Absurdity—in which I try to account for it. I believe these visions are real as such; they are part of a natural feedback mechanism intrinsic to the human mind, which seeks to dislodge it from ossified worldviews that, despite having become stable, no longer serve the advancement of our understanding of ourselves and nature. The visions in question emerge from collective, phylogenetically ancient layers of the human mind shared by all of us, which, for being incapable of language and conceptual reasoning, communicate to the executive ego through dream-like, immersive metaphors. They should be taken seriously, just not literally.

But I do not think that the ‘high strangeness’ phenomenon is the same as the ‘nuts-and-bolts’ UAPs. Conflating the two, in my opinion, may make it impossible to account for either, as no one account will be consistent with the sometimes mutually contradictory characteristics of both. For this reason, and because I have explored the ‘high strangeness’ phenomenon in previous work, I shall henceforth exclusively discuss the ‘nuts-and-bolts’ UAP phenomenon.


The idea that the intelligence behind the UAPs is terrestrial and ancient is itself not new. Dr. Hal Puthoff calls it the “ultra-terrestrial” hypothesis. He raises the possibility that remnants of a pre-Diluvial high-tech human civilization—think of the Atlantis myth—may have survived at the end of the last ice age and remain active today, though discreet in their activities.

The problem with this hypothesis is that any truly high-tech civilization—unless it has moved underground very early, which may not be plausible due to difficulties related to the space required for industrial and logistical infrastructure, difficulties with waste management and pollution, etc.—leaves vast and long-lasting footprints on the terrain and environment, such as mining holes, landfills, urban infrastructure, artificial pollutants such as microplastics, etc. These footprints, though degraded, would have remained conspicuous enough over the period of only several thousand years since the last ice age. Yet, we find no such traces predating our own civilization.

Because high technology development requires—at least at first—extensive industrial infrastructure, any ancient civilization capable of technology as advanced as that in UAPs will almost inevitably have had to go through steps of industrialization and resource extraction analogous to ours, and then some. It will have had to go through phases of urbanization, mining of metals and burning of hydrocarbons, the construction of vast industrial parks, logistical/transport infrastructure, and so on. If the intelligence behind UAPs is terrestrial, it will thus need to be ancient enough for the associated footprints to have been almost completely erased by natural weather and geological processes. Yet, it will also need to be recent enough to already have had access to fossil hydrocarbons to fuel the early stages of its industrialization process. Are these seemingly conflicting constraints reconcilable?

They are, as per the so-called “Silurian Hypothesis” first proposed by Gavin Schmidt and Adam Frank in a 2018 paper on the International Journal of Astrobiology. The idea is as follows: our planet has existed for about 4.5 billion years, with life on it for about 4 billion years. The genus Homo, to which we belong, has been around for less than 3 million of those 4 billion years; the blink of an eye in geological terms. And modern humans—Homo sapiens—for just 2 or 3 hundred thousand years. There is, thus, plenty of time and opportunity for other non-human species to have arisen on Earth, developed to a level of technology far beyond ours (imagine where our own science and technology will be in a mere thousand more years, if we don’t kill ourselves before that), and then to have effectively vanished due to one or more of the myriad possible civilisation-ending cataclysms that could end our own (climate change/collapse, comet/asteroid impact, pandemics, solar storms, thermonuclear war, etc.).

Any sign of abandoned urban and industrial infrastructure is unlikely to survive a period of only a few million years, due to weather erosion. Synthesized chemicals, alloys and other compounds, technological artifacts, as well as terrain signatures such as mining holes, are ultimately unlikely to survive the constant recycling of the Earth’s crust through plate tectonics. What is now the Earth’s crust will eventually sink into the molten asthenosphere and mantel beneath, where it will be reforged, just to eventually re-emerge through volcanic activity as a brand-new crust. As a rough estimate, if we assume an average plate movement of a few centimeters per year, it could take only tens of millions of years for large swathes of the Earth’s crust—especially the ocean crust but, to a more limited degree, also the continental crust—to be recycled in this manner. No conspicuous remnants of an ancient, technological, nonhuman civilization would likely survive all this.

The question now is, when were fossil hydrocarbons first available in large enough quantities to fuel the initial growth of an ancient industrial civilization? Dr. Schmidt and Dr. Frank estimate that this was already the case in the Carboniferous period, about 350 million years ago, which leaves us with a window of hundreds of millions of years for industrial NHIs—multiple different ones—to have developed on Earth.

Notice that my claim here is not that it is likely that high-tech nonhuman civilizations have emerged on Earth before us; I cannot evaluate the probabilities involved. My claim is that, based on what we know, such civilizations are not impossible or inconsistent with the geological record. On the contrary: as Dr. Schmidt and Dr. Frank point out, the record shows several periods of global warming consistent with large-scale industrialization.

Now, since we cannot visit an NHI city today, it is necessarily the case that, if such ancient terrestrial civilizations ever existed, they have largely died out—at least as far as the surface of the planet is concerned. This, however, is not implausible: as we know from our own case, civilizations can start, reach high-tech levels, and then be annihilated in a mere few thousand years. Indeed, although our civilization is still going, we are painfully aware of how easily and quickly it can be brought to a swift end tomorrow, in a thermonuclear war, asteroid impact, climate collapse, or a more deadly pandemic than the one we have just survived, etc.

Yet, it is unlikely that all members of our species would die in a planetary catastrophe. There is a good chance that few but enough of us would survive in shelters and preserve a minimum level of knowledge to keep some of our technology going, especially if we get some advance notice of the impending doom. In as little as a decade or two from now, for instance, we will likely have mastered the technology of small-scale, portable, clean nuclear reactors that can be buried in a backyard (or a cave) and provide effectively unlimited energy. Portable 3D printing technology is reducing our reliance on centralized, large-scale manufacturing facilities. Our computers, which were once the size of buildings, now live in our pockets. If we extrapolate these trends for another mere century or two, it is reasonable to imagine that technological miniaturization and portability will allow our civilization to survive at a reduced scale in, for instance, underground shelters. It is thus not unreasonable to imagine, purely speculatively, that the same could have been the case for ancient NHIs hypothetically behind today’s UAPs.

Any culture once exposed to the magnitude of a planetary catastrophe will have a historical trauma transmitted down the generations through myth and storytelling, similarly to—but much more acutely than—how flood stories have survived since the end of the last ice age. Such a culture will be wary of the planet’s surface, for the latter is a notoriously exposed and volatile region: it undergoes far more extreme temperature swings than, say, the deep oceans and underground caves; it is prone to severe weather that can ruin crops and flood entire cities; it is exposed to irradiation from solar storms and other cosmic events, which can ruin technology and life; it is extremely vulnerable to comet and asteroid impact, as the dinosaurs found out; etc. And since such a post-apocalyptic culture would have been reduced to relatively few members, their requirements for living space would also be relatively modest. Depending on the surviving level of their technology, they could have made a home for themselves underwater or underground. A few generations of (directed) adaption—genetic and cultural—to such an environment would render the planet’s surface perhaps as alien and inhospitable to them as the Mariana Trench is to us. They would be okay with allowing the monkeys to run amok on top of the roof (provided that the monkeys don’t start a thermonuclear war and compromise the entire house), but would rather stay safely indoors.


Science fiction has inculcated in our culture the notion that communication with another, completely different species is a matter of translation or word-swapping; something akin to what we do to convert Chinese text into English. Indeed, we now have a completely manufactured sense of the plausibility of such an idea. But it is naïve.

Ordinary translation presupposes two important things: a shared cognitive structure (templates of thinking) and shared empirical references. The latter is easy to see: if both you and I have already had the experience of seeing and driving a car, then to understand each other we just need to learn what word the other uses to denote that experience. However, things are more subtle when it comes to shared cognitive structures, as they operate based on abstractions, not direct empirical experiences. For instance, think of the concept of ‘flow’: it can be used to denote a concrete empirical experience, such as watching a river flow. But it is also used in much more abstract ways: we say that ‘time flows’ even though we can’t see time, let alone its flow; we speak of the ‘flow of ideas’; we say that ‘we are in the flow’; and so on. ‘Flow’ is an abstraction that refers to sequential, somewhat ordered changes of state, something entirely bound to our human mode of cognition. To understand ‘flow’ one needs to share the basic cognitive templates that gave rise to the concept in us to begin with. Without these shared templates, it is impossible to merely translate the word.

All humans share these basic cognitive templates by the mere fact of being members of the same species. In other words, we think alike because we are alike. Some linguists—such as Noam Chomsky—go as far as to say that the basic structure of all human languages, which he refers to as the ‘Universal Grammar,’ is biologically encoded in the human cognitive system. Although Chomsky’s opponents argue that language is merely invented and shared by convention, it is still necessarily the case that the underlying foundations of whatever is invented reflect cognitive modalities the inventor shares with all other members of their species. It is this commonality that enables what we call ‘translation’ across human languages, and we tend to take it entirely for granted.

But NHIs, by definition, don’t share such commonality with us. After all, they belong to a different species. Their cognition will almost certainly unfold with vastly different patterns and modalities. Even their logic may bear little resemblance to our own Aristotelian axioms. Moreover, their cultural context is bound to be entirely different from ours, leading to different empirical references: originally, they may not have had a cognitive category for, say, ‘car’ or understand the concept of a wheeled vehicle (for instance, if they are an aquatic species). It is naïve to expect that NHIs could learn our language as easily as a Chinese person can learn English. The underlying cognitive structures and references won’t line up; why should they?

Nonetheless, this doesn’t mean that we and NHIs can never communicate. What it does mean is that achieving this feat will require an effort to enter each other’s cognitive inner space—literally. In other words, before they could communicate with us, they would have to gain direct access to, and manipulate, our abstract mental processes. This is not something that can be casually achieved in the way I can pick up Italian during a holiday.

You will be closer to appreciating the difficulties if you think of whales: we know they have a language that scores higher in some relevant measures of complexity than our own. Yet, we can’t translate ‘Whalish’ into any human language, even though whales, just like us, are air-breathing, breast-feeding mammals.

To really appreciate the difficulties we have to go beyond whales—close relatives of ours—and imagine that, say, praying mantises—ancient insects much less related to us than whales—would have some form of language, and that we would try to communicate with them. Now we’re getting closer to the mark, for the cognitive templates and inner logic of insectoids are bound to be very largely incommensurable with ours. The challenge here is not mere translation; to speak ‘Insectoidish’ one would have to enter the cognitive space of insectoids—i.e., enter their mind.

Intellectual-level communication between more advanced terrestrial NHIs and us will require direct access to our cognitive processes. They will have to directly modulate our own abstract references and modes. In other words, they will have to convey their ideas to us by prompting our own mind to articulate those ideas to itself, using its own conceptual dictionary and grammatical structures. And because their message—a product of their own cognition, incommensurable with ours—is bound to not adequately line up with our grammar and conceptual menu, this articulation will perforce have to be symbolicmetaphorical; it will have to point to the intended meaning, as opposed to embodying the intended meaning directly, or literally.

There is plenty of clinical precedence for this in the literature of depth psychology. Analytical Psychology, for instance, maintains that the deeper, evolutionarily ancient, instinctive layer of our mind, for not having the language capabilities of the executive ego, speaks to us in dreams and visions through symbols, and metaphors. It can’t tell us in English, for instance, that time is flowing while we procrastinate, prompting us to act. So it may, instead, trigger and modulate a dream in which we, say, accidentally drop our backpack in a fast-flowing river and watch helplessly as it floats away. If the deeper layer of our mind, for being phylogenetically primitive, is incapable of articulating the conceptual abstractions ‘time,’ ‘flow,’ and ‘procrastination,’ it can still point symbolically to its intended meaning; it can still confront us with imagery that evokes the same underlying feeling—a sense of urgency—that would have been evoked by the statement, “time is flowing while you procrastinate.” This is what intellectual-level communication looks like when the interlocutors do not have commensurable cognitive structures. And this is how we may expect NHIs to communicate with us, if they have the technology required to reach directly into our minds and manipulate our cognitive inner space.

Notice the similarity between this and the ‘high strangeness’ class of observations: both entail symbolic communication by means of direct manipulation of our inner cognition. In the latter case, the communication is between deeper and shallower—primitive and modern, respectively—layers of our mind, taking place naturally and spontaneously. In the former case, the communication—likely mediated by technology—is between an NHI and a human, taking place in an artificial and deliberate manner. But both are metaphorical, akin to dreams and visions. This similarity is part of the reason why we feel tempted to conflate the ‘nuts-and-bolts’ and ‘high strangeness’ classes of observations.

In conclusion, I submit the hypothesis that, when UAPs manipulate our perceptions during an encounter, they are, in fact, attempting to communicate in the only way they can. Analogously, if you are hiking on a remote trail and come across a wild bear—another terrestrial species with a cognitive structure different from ours, which we encounter by chance as they go about their business in their own habitat—the bear, too, will communicate with you in the only way it can: through meaning-evoking body posture and sounds; and you will even understand it. The difference is that UAPs are better, more nuanced, and more sophisticated at the task.


For every useful, truly scientific hypothesis, there must be an experiment or a passive observation under controlled conditions that can either confirm or contradict it. As we’ve seen in the foregoing, the hypothesis in question is that the NHI—or NHIs—behind the ‘nuts-and-bolts’ UAP phenomenon is(are) ancient but terrestrial. We’ve discussed the characteristics of the phenomenon that motivated the hypothesis to begin with: (a) the frequency of UAP encounters, which suggests that they are from here and we meet them as they go about their business, just as we meet a bear in a trail; and (b) their interest in human activities that may jeopardize the habitability of this planet, such as nuclear installations and military exercises. But these characteristics aren’t conclusive. So just what could be conclusive?

If it is true, as Mr. Grusch claimed in his testimony to Congress in July 2023, that the US government has “biologics”—that is, the bodies of crashed UAP pilots—then a biochemical analysis of these biologics, if not conclusive, would at least be very indicative of whether they are terrestrial or not.

All terrestrial life we have studied in detail thus far, despite their drastic morphological differences—think of the differences between an amoeba, a praying mantis, and a cat—share the exact same biochemistry: they have two-stranded DNA with sugar-phosphate backbones and four nucleobasis (cytosine, guanine, adenine, and thymine) that form two possible base-pair configurations. Despite their extreme morphological differences, all terrestrial life thus looks the same when observed ‘under a microscope with sufficient magnification,’ so to speak.

Yet, the functions performed by this very specific biochemistry are multiple-realizable: there are many other conceivable ways in which these functions could be performed based on different biochemistry. The fact that all life we’ve studied thus far shares such specific biochemistry means simply that we all have a common ancestor dating back to an abiogenesis event: the rise of life from non-life. That event has defined the biochemistry we have all inherited. But it could just as well have been quite different; there is no a priori reason why biochemistry must be the way it is in us.

Indeed, a different event of abiogenesis—there is no a priori reason why life must have arisen from non-life only once on Earth either—could have set a different biochemistry; one still capable of storing the organism’s body plan, of constructing the organism’s building blocks (proteins, in our case), of metabolizing, and of passing the organism’s body-plan to the next generation via reproduction; yet one different from ours. This is acknowledged in biology in the hypothesis of a “shadow biosphere”: there may, in fact, be organisms on Earth with biochemistry different from ours, because they may be descendants from a different abiogenesis event; we haven’t detected them yet because we haven’t done a detailed biochemical analysis of most organisms on the planet.

If even terrestrial organisms, which arose and evolved on this very planet, could have biochemistry distinct from ours, it stands to reason that organisms evolved on another planet, with different environmental conditions and chemical composition, are very unlikely to have the exact same biochemistry we do. That would require an implausible coincidence of literally cosmic proportions, even under the assumption of convergent evolution at the level of the phenotype (i.e., body form).

Therefore, if the biologics in the freezers of the powers-that-be have the same biochemistry we do, I believe it is safe to assume that they are terrestrial; they are our older cousins—likely forever traumatized by earlier planetary cataclysms—and certainly not aliens.

Another prediction of the ‘ultra-terrestrial’ hypothesis is this: the materials—say, the metals—used in the UAP craft should have isotope ratios compatible with an earthly origin, as opposed to one outside the solar system. If the powers-that-be are in possession of such craft, this shouldn’t be a difficult test to perform.

Together, the two test results suggested above, if mutually consistent, should be conclusive.


The hypothesis I put forward is that, if the ‘nuts-and-bolts’ UAP phenomenon and the Non-Human Intelligence(s) behind it are real, they are unlikely to be extra-terrestrial. Instead, they may consist of remnants of industrial, technological NHIs that evolved on Earth up to 350 million years ago. We cannot find conspicuous archaeological or geological footprints of such civilizations because, according to the so-called ‘Silurian Hypothesis,’ not only weather erosion but also the regular recycling of the Earth’s crust through plate tectonics, erase them. The anthropocentric notion that nothing intelligent has arisen on our planet in the billions of years for which no conspicuous evidence would have remained on the geological record is unjustified. There has been plenty of time and opportunity for many technological, industrial, but non-human civilizations to have arisen and disappeared from the surface of the Earth.

Though I understand that many may consider this hypothesis disturbing at some level, it does not require anything fundamentally beyond natural processes we know to exist: we know that intelligent life can arise on this planet, given its environmental conditions; we know that industrial civilizations can arise, develop, and go extinct in a period no longer than a few thousand years, which is the blink of an eye at a geological scale; we know that our own technology today would have looked like magic to the Great Goethe, only 200 years ago; we know that intelligent species that evolved the ability to act according to an abstract ethical code can operate under a policy of non-interference towards less evolved life (just think of human wildlife researchers); and so on. The present hypothesis requires nothing more than the foregoing. As such, there is nothing unnatural or truly extraordinary about it. If it violates our sensitivities, then this informs us about our sensitivities, not about the plausibility of the hypothesis in a naturalist framework.

Notice, however, that the hypothesis proposed here presupposes the UAP data disclosed thus far to be authentic, and not the result of a sprawling disinformation campaign. In the latter case, the key motivations and empirical ground for the speculations in this essay would be void, and the hypothesis should be disregarded in its entirety.


I am very grateful to Dr. Hal Puthoff, Dr. Garry Nolan, Rob van der Werf, and Paul Stuyvenberg for the generous feedback provided on earlier drafts of this essay. 

Bernardo Kastrup is a Dutch philosopher, computer scientist, and the executive director of the Essentia Foundation. He has a Ph.D. in philosophy and another in computer engineering, and has worked as a scientist in some of the world’s foremost scientific laboratories. His main interests are metaphysics and philosophy of mind. He lives in Veldhoven, Netherlands. This essay originally appeared on Kastrup’s personal website