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Will We Ever Philosophise With E.T.?

Malcolm E. Brown & Steve Hubbard argue that it’s unlikely.

Our inquisitive species has long wanted to know if intelligent beings exist on other planets. The last century gave us the technology to actively seek an answer, and the last decade a heightening sense that an answer may be within reach. This quest exquisitely blends philosophy and science, but within it natural science has overwhelmed philosophy, and social science has been almost ignored. If we cannot redress those imbalances here, we at least hope to highlight them.

Each of us thinks, ‘I am here’. This, we realise, is not straightforward for philosophers. However, we may accept as a starting point that on Earth there seem to be many self-aware others like us – let’s call ourselves Homo sapiens – as well as about nine million other species. The phrase ‘others like me’ carries centuries of intellectual baggage, but perhaps we can say that a quintessential condition to be like me is that we can engage in human intellectual communication, both today and, using records, down the centuries. We apologise if the word ‘human’ in this phrase offends, but we can see no way to avoid it; it is, perhaps, both the lynchpin and the Achilles heel of the alien communication issue. As far as is known, we have only ever had intellectual communication with other humans. In this article we hypothesise that, unless aliens from other planets are also Homo sapiens, intellectual (that is, high level) communication with them will be impossible. This may appear over-emphatic, but note that, despite co-evolution side-by-side on the same planet over billions of years, humans have never had a meaningful conversation with any other species.

It seems an enormous assumption that any intelligent life that has evolved on another planet would also be Homo sapiens. But for those who hope for neighbours with whom to communicate and even philosophise, we suggest the situation is even worse, because, as we hope to show, even the existence of extraterrestrial Homo sapiens does not guarantee that we could intellectually communicate with them.

Supplementing the Drake Equation

The astronomer Frank Drake made key contributions to the search for extraterrestrial intelligence, including in 1961 formulating an equation to predict the prevalence of intelligent species in the galaxy. One version of the Drake Equation says that if we call the number of communicative civilizations in our galaxy N, and:

a = average rate of star formation in our galaxy,

b = fraction of stars that have planets,

c = fraction of planets that can potentially support life,

d = fraction of potentially life-supporting planets that develop life,

e = fraction of those planets on which intelligent civilized life has developed,

f = fraction that have developed communication technologies releasing detectable signs into space,

g = time during which a civilisation releases detectable signals,

then N = a b c d e f g.

(The form in which it’s usually written is N = R* fp ne fl fi fc L.)

That is to say, the number of active communicative civilizations currently in our galaxy equals the average rate of star formation in our galaxy times the fraction of stars that have planets, times the fraction of those planets that can potentially support life, times the fraction of potentially life-supporting planets that do develop life, times the fraction of those planets on which intelligent civilized life has developed, times the fraction of those intelligent species that have developed communication technologies releasing detectable signs into space, times the length of time during which that civilisation releases those detectable signals!

ET 1
Neither Homo nor very sapiens
Toy Story image © Buena Vista Pictures Distribution 1995

For an example of the numbers to put into the equation, astronomers have recently discovered that b, the fraction of stars that have planets, is at least 1/6. However, debate abounds about the other values needed to populate the Drake Equation, and the meaning of the result. Most terms in the equation are heavily reliant on somewhat speculative data from the natural sciences. The input of social sciences to quantify factors e, f and g is even more scanty. Indeed, estimates of N vary from 1 (just us), to thousands, even millions, in our galaxy of two hundred billion or so stars.

But we want to increase your sense of isolation by suggesting that the popular, and sometimes scientific, literature, is wrong to assume that if an active extraterrestrial intelligence exists with whom information can be exchanged, then intelligent communication will follow. Much human thought (including, arguably, the Drake Equation), is overwhelmingly anthropocentric. That will be very difficult, perhaps even impossible, to overcome. ‘Hurdles’ in the components of the Drake Equation are frequently discussed as impediments for life to overcome on a route from the primitive universe to the first appearance of life, to technological civilisation with interstellar communications. We suggest further that the Drake Equation does not make explicit the hurdles following the exchange of information before there can be intelligent communication. We refer to these hurdles as the cultural phase. The questions they raise may particularly interest philosophers.

Pre-Biological Hurdles

But the first hurdles to E.T. communication are pre-biological. With further planetary exploration, we may discover that overcoming the pre-biological phase is relatively easy. About 10.4 billion years after the Big Bang, after traversing several hurdles, conditions allowed the appearance of the first life on Earth, about 3.4 billion years ago. That mother of all mothers is often called ‘Lua’ (Last Universal Ancestor-type organism).

Generally, the pre-biological phase and genesis of Lua is scientifically non-controversial. We already know that it has occurred on one planet. That sample size also applies to evidence of successful jumping of hurdles from Lua to intelligent civilised life. There is but one known example of that, too: humankind. We could say that out of all the star systems we have studied in sufficient depth to be sure, the success rate for civilised evolution is 100%. However, scientists, and others, are uneasy with a sample size of just one.

Biological Hurdles

The second set of hurdles to communicating among the stars is in the biological phase. Actually, biological and cultural hurdles overlap. Maybe it’s common for a planet to evolve creatures with sight, hearing, taste, smell, and touch, but much rarer, with many extra challenging hurdles, to get to a technologically communicating civilisation.

Biological hurdles that need to be overcome include the need for increasing complexity and variety of life-forms, bigger brains (on Earth, seen also in cetaceans and octopods) and the use of tools (on Earth by crows and others as well as primates). We know that these hurdles have been jumped at least once on Earth. Once evolution starts, those species best adapted to survive, do so. The odds become stacked in favour of their survival and what happens is no longer just random chance. This may apply to the evolution of intelligence, too. Evidence exists of a degree of intelligence in other species. A dog and its owner can communicate on certain matters, such as the dog wanting to go for a walk. However, the human appears unable to philosophise with the dog.

Let’s consider our senses: sight, hearing, taste, smell and touch. Biologically, humans are two-metre high bags of impure water under slight pressure, most of our sense organs being on our faces rather than the backs of our heads. The range of each sense for humans is also extremely narrow, and tuned to our own evolutionary needs. If we compare ourselves with any other creature, we find huge differences in range and sensitivity. The sonic facilities of bats are well known. Equally impressive to us are the sensitivity of spiders to vibration and the visual acuity of birds of prey. Butterflies can perceive whether a solution is sugar or another sweet chemical, while humans struggle. Salmon can smell the distant waters of their birth to which they must swim to spawn. Aliens possessing a similar exquisitely-developed sense of smell, might find our normally undetectable fragrance of putrescine and cadaverine utterly repugnant.

The tools of our technology can extend the range of human senses by transposing different ranges of sensory inputs into the narrow ranges our bodies can perceive, so that, for example, we see ultraviolet light as blue. Aliens may have different biological ranges for perception. Translation between the two ranges, with distortion small enough for the result to be intelligible, makes enormous demands on the technology of both humans and aliens.

Some of our fellow creatures on Earth have evolved senses we didn’t even have a conception of before we developed instrumentation technology. Using our modern technology, humans are beginning to understand the navigational techniques of bird migration. Cuttlefish can detect the angular polarisation of light with a sensitivity of the order of a degree. Communication based upon light polarisation may seem common sense to cuttlefish-like aliens.

ET 2
“What do you mean there’s no more fish?” An intelligent species we already can’t communicate with

Considering now our appearance, our eyes are not at the side of our heads, as rabbits’ eyes are, always looking around, through nearly 360 degree vision. We are not prey, waiting to be eaten. Our eyes are wide apart, and at the front of our heads. These stereoscopic eyes brand us as predators. We do the eating. Aliens may take one look at us and flee. Even today, humans routinely ‘communicate’ with dolphins – indisputably intelligent, and so sociable that they call each other by names – by killing and eating them.

The jaws of mammals on Earth hinge vertically, not horizontally. We expect such jaws. Suppose you met a human who had jaws that hinged horizontally, like a door. Would you welcome that individual? Would you want to communicate with, or avoid, an alien flashing horizontally-opening jaws? Large insect-like aliens often feature in sci-fi B movies. Insects have mandibles that move side-to-side.

Our very bodies may confuse aliens. Just what do they address within our bodily boundary? Is it the 90% of our cells that are microbes: archaea (the most ancient life-forms), bacteria, fungi etc; or the small minority – only 10% – of our bodies that are mammalian cells? The micro-organisms have piggybacked with us over the hurdles, and without those microbes, we die.

Cultural Hurdles

A third phase of hurdles has been necessary for us to overcome to reach the later stages of the evolution of us. These hurdles would reduce even further the probability of there being other civilisations with whom we could communicate. Some factors may block attempted telecommunication, arriving ahead of us like a pilot wave before a ship’s prow. This may be due to the aliens’ immensely different communication technology (remember the taken-for-granted importance of polarisation for the cuttlefish aliens) and/or the message contents (what really interests them). Another hurdle may be that the cultural distance between the two civilisations is so immense. Wet carbon-based meat machines such as us, and dry silicon-based computers, may struggle to find enough common intellectual ground. Some intelligences with biological origins much older than ours may have evolved to no longer require bodies. Those intelligences could be forever opaque to our puny intellects. Even amongst human cultures there is the potential for accidental misunderstandings that could offend, even gravely. To Caucasians, it’s immaterial which hand is used to shake another’s hand. However, to some Asians, it must be the (clean) right hand. The left hand is used for less hygienic purposes, and would insult. Sometimes within humanity, a culture profoundly misunderstands another culture. For example, during the British invasion of Tibet in the early twentieth century, the soldiers/explorers thought that the clapping of natives was a sign of welcome. It was to drive away devils. Notice how complexity explodes on examining one difference in the fine grain of just two cultures, both human. Each group, perceiving through disparate cultural spectacles, struggles to understand the other’s viewpoint. Indeed, some gulfs between sincere intelligent individuals of the same species may seem insuperable. Imagine how much wider the potential gulfs between human and extraterrestrial intelligences.

The consequences of first contact with an extraterrestrial intelligence could vary depending on a complex matrix of human cultural circumstances. For instance, where contact is made matters. Sweden or North Korea? When matters. During peace or war? Who matters. Astronomers, philosophers, atheists, or theologians?

A culture and its perspectives may rapidly change. Today we take it for granted that the Earth is spherical(ish) and not flat. It has become meaningless to ask questions about our fate if we fall over the edge of the Earth. Since Einstein, we’ve also inhabited a relativistic universe where how we perceive depends on how fast we’re moving. Since Freud, we are aware that our brains buzz with notions, some profoundly embarrassing, that only occasionally emerge into our consciousness. A telepathic alien might unthinkingly communicate with our unconscious, instead of the public persona that diplomacy has filtered – and then flee. Maybe there would be justification. As mentioned, we are predators, and our history is of shedding the blood of others just a little different from ourselves. This all forewarns of great difficulties for any intercultural human/alien understanding.

These are speculations, or guesses. However, note that guessing is a part of the scientific method, where it is known as ‘forming a hypothesis from observation’ for subsequent testing or corroboration. Choose your favourite guess about the worlds of extraterrestrials. Common themes include disparate time and space scales, other dimensions, or mutual inscrutability because of other unbridgeable gaps. Another possibility is that there are so many civilisations that aliens haven’t yet got around to communicating with us. Yet the absence of messages from that multitude, or their self-replicating autonomous exploratory robots, may be evidence against that perspective. Scientists endeavour to be open-minded and never forget that there are things that we do not know that we do not know. The authors suggest that, when reflecting upon communication with aliens, this matters.

Imaginative Hurdles

It is a given for anthropologists that if one human culture thinks that it understands another, it should think again. One weak version of our philosophical difficulty here is the Sapir-Whorf hypothesis. Sapir and Whorf argue that language affects how individuals conceive reality and react to it, including cultural reality. If so, that means that our language limits our conceptions, our world.

However, within the cultural phase of the interstellar communication issue lurks the hurdle of an even deeper problem. In ‘What Is It Like To Be A Bat?’ (Philosophical Review, 1974), the philosopher Thomas Nagel argued that in principle humans cannot imagine what it is like to be other species, just because humans have differently tuned senses, and completely lack some of the senses of other species (e.g. the echo location bats use) and the corresponding perceptual apparatus in our brains. That lack is an insuperable modifier of all input; it homogenises all human thought. Nagel’s key point is that, no matter how non-anthropocentric humans strive to be, what we can perceive or conceive becomes just a human interpretation. Put another way, Nagel’s point is that humans can never truly imagine what it’s like to be a bat; humans can at best only ever know what it’s like being a human imagining they’re a bat.

Our killer observation on the communication issue bears repeating here: despite co-evolving over billions of years, humans have never had a meaningful conservation with any other terrestrial species, even a companion species such as a dog, or a flea. About half of Western households contain pets, so are inter-species. Therefore, presumably, at least half of readers have personal experience of hanging out with another species. But note the anthropocentric overtones of ownership.

Our interpretation of these latter major hurdles is that attitude matters. Why should aliens and/or humans invest time that might be more productive elsewhere? Moreover, attempting to communicate with the other carries risks. Even between humans, some unintended consequences of contact between societies of differing technological advancement, intended to be benign, proved devastating to the health and sanity of whole societies. An Australian society using stone axes crumbled after steel tools were introduced.

Similarily, there are ‘millennial’ and ‘catastrophic’ models concerning our meeting aliens. For the latter, think Independence Day. Maybe one species is a superpredator: it removes civilisations after they have achieved a certain level of technological advancement, not because of a threat to the superior civilisation but merely because the lesser species would irritate, like a buzzing fly. We humans are not, as yet, the superpredator’s prey. Alternatively, extraterrestrials may avoid us because we are too dangerous; remember our predator’s eyes, and our WMDs. Maybe aliens feel that it is safer to stay at home and surf the web.

To summarise, the probability of there being alien intelligence with which we can intelligibly communicate is remote even if we only consider the hurdles within the pre-biological and biological phases. Allowing for the hurdles that social sciences and philosophy introduce makes intelligent communication with aliens seem even more unlikely.

ET 3
Mars Attacks! image © Warner Bros Pictures 1996

Numbers Large and Small

There are 200 billion stars in our Milky Way galaxy, and possibly 100 billion galaxies in the visible universe. This easily leads to the assumption that there must be alien intelligences with whom we could communicate. We suggest the numbers do not bear this out.

For our calculation we have two competing sizes of number – the large number of stars and the small probability of our existence. Astronomers are able to determine star numbers both in our galaxy and universe as a whole with reasonable precision; but the numbers to put in each of the hurdles of the Drake Equation, or of their probability of being overcome, is highly uncertain. Each hurdle reduces the probability, and there are many hurdles.

The crucial consideration is how these numbers compare. Do the large number of stars overwhelm the small probability of ‘another us’, or is the likelihood of ‘another us’ so small that there simply are not enough stars? To answer we multiply these two numbers and look at the result, because that gives some idea of how many communicating civilisations there might be. If the answer is in the hundreds or thousands, then it is more likely we have company; if it is small, then we are probably alone. For example, even if we assume each hurdle is overcome relatively easily, with a probability of 1 in 100, and there are just ten hurdles distributed across our three phases of development, the overall probability is such that, when multiplied by the approximate number of stars in the universe, the result is around 1,000. Put differently, with just these few, relatively easily leapt, hurdles, we can expect about 1,000 intelligences with whom we could communicate in the whole universe. However, within any currently envisioned technology, communication outside our galaxy is inconceivable. So to be more realistic, we reduce the number of stars to those within our galaxy, which correspondingly reduces the expected number of intelligences. Then, instead of 1,000, we would expect to have only 1/1,000,000,000th (a billionth) of one in our whole galaxy. Using arithmetic alone, we conclude that other intelligences potentially near enough for communication are effectively absent. It’s as if we’re alone. Our own existence is itself some fantastic fluke.


Any positive answer, or hint of a positive answer, to our question, would change everything, perhaps in philosophy more than any other discipline. It could utterly alter our perception of ourselves, a paradigm shift of almost unimaginable magnitude. Alternatively, extraterrestrials’ philosophy, ethics and scientific method might be familiar to us, cutting through all other differences between us and them. We may share sufficient intellectual ground with them to elevate our self-esteem to being the joint holders of god-like universal knowledge. But suppose philosophy and so on were completely different, despite the aliens arriving at a technology sufficiently similar to ours to be able to communicate with us? Arguably this would have an impact on every intellectual discipline, but philosophy would need a complete rewrite. Our ‘recalibration’ may cause us to contemplate our intellectual prowess as comparable to that of earthworms.

Or maybe we can have high-level communication of just the sort we have among ourselves. But for this aliens would need to be Homo sapiens, and at a similar stage of intellectual development, allowing for the time lapse in communication. Whilst not impossible, this appears sufficiently unlikely to us that we conclude that we are effectively unique.

Should we bother to use our technology to continuing listening? Yes. If a comprehensible signal is received, it will not just indicate that we have neighbours – staggering in itself – but that there exists a bias or convergence of almost unimaginable strength towards the development of groups of beings intelligent like ourselves, and that all evidence and logic to the contrary must be flawed. This possibility, however unlikely, makes the effort worthwhile. Anyway, given our intrinsic inquisitiveness, how could we not try and find out if there is anyone out there?

© Dr Malcolm E. Brown & Dr Steve Hubbard 2016

Malcolm E. Brown, sociologist, and Steve Hubbard, physicist, both amateur astronomers, were astonished when they investigated this can of cognitive worms.


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