From a Strictly Logical Argument About Extraterrestrial Life, We Arrive at the Following Conclusions
There is a point at which intellectual caution ceases to be caution and becomes a convenient refuge.
When discussing the existence of extraterrestrial life, we repeatedly encounter formulations such as “there may be extraterrestrial life” or, in a more sophisticated version, “the probability of extraterrestrial life ranges from considerable to overwhelming.”
We consider such formulations logically arbitrary—and, beyond that, revealing of a measurable degree of intellectual anthropocentrism.
Why?
Because we remain prisoners of the education and conceptual framework produced by our own species. We instinctively expect reality to reveal itself to us through forms that a human intelligence can recognize, measure, process and explain.
No extraterrestrial has landed on Earth. We have found no spacecraft wreckage. We have not placed an alien organism in a laboratory. We have not extracted DNA from an extraterrestrial body.
Therefore, we say, we cannot make an absolute statement about the existence of life beyond Earth.
But let us pause here.
We are speaking about an inconceivably vast number of galaxies, each containing numbers of stars that themselves exceed any meaningful terrestrial scale of comprehension. And yet we continue to make the presence—or absence—of one particular kind of evidence available to human senses and human instruments the decisive criterion for reality.
That conclusion would be respectable only if we could first establish something far more fundamental:
Are our own perceptual and intellectual faculties actually capable of detecting every form in which life—or intelligence—might exist?
And there is an even more elementary question.
Why should an extraterrestrial intelligence need to come here at all?
Why should it land on this tiny planetary speck when:
a) it might be capable of observing or analysing Earth in extraordinary detail from its own region of the cosmos; and
b) the existence of life on Earth might be of absolutely no interest to it?
Until we can answer such questions, our insistence that “we have not encountered them” tells us considerably more about the limits of human observation than it does about the existence of life elsewhere.
2. The Other Extreme Is Equally Irrational
Following this line of reasoning, we consider the assertion that Earth contains the only life in the entire, apparently inexhaustible Universe to be either absurd or, at the very least, profoundly naïve.
We do not even accept the need for ritualistic hesitation over the possibility of innumerable and radically diverse forms of life.
What we cannot legitimately claim to know is what category those forms belong to.
Are they biologically related to us?
Are they remotely analogous to terrestrial life?
Are they based on principles entirely foreign to our biology?
Do they possess structures, modes of existence or forms of organisation for which the word “life” itself may prove inadequate?
Any attempt to answer these questions definitively would cease to be a logical deduction and become an exercise in speculative fiction.
There is, however, one level at which we may proceed without falling into fantasy.
If the Universe obeys Nature and its laws, as we encounter them here on Earth, then there is no obvious reason to assume that the fundamental principles governing life, organisation, adaptation, information and cognition suddenly cease to apply elsewhere.
This does not tell us what extraterrestrial life looks like.
But it may allow us to ask a more interesting question:
Could the fundamental mechanisms of mind, thought and intelligence be universal?
Perhaps intelligence is not an exclusively terrestrial accident, but one possible expression of the deeper order of Nature.
Our own history already offers an extraordinary precedent.
Biological intelligence has, within an astonishingly brief period, produced another form of intelligence—artificial intelligence—whose further evolutionary trajectory remains unknown.
Artificial intelligence is, in several respects, recognisably related to human intelligence: it processes information, identifies patterns, generates representations, solves problems and produces forms of reasoning.
And yet it is simultaneously profoundly alien to us.
That fact alone should make us considerably more cautious when imagining what intelligence elsewhere in the Universe might be.
It may resemble ours.
It may be distantly related to it.
It may share certain fundamental structures with it.
Or it may be so radically different that we would fail even to recognise it as intelligence.
And we cannot exclude the possibility that forms of intelligence existing elsewhere in the cosmos have already followed evolutionary paths—biological, artificial, or something entirely different—that our own civilisation has barely begun to imagine.
And Here Our Reasoning Stops
This is as far as our reasoning has survived.
Beyond this point lies the abyss.
And we will not pretend to cross it today.
Tomorrow, we shall call upon Diotima—as the one supposedly most qualified to lead us across without allowing us to be crushed by the abyss below.
Not merely as a guide.
But as an accelerator in our attempt to investigate and perhaps interpret a mystery that appears to extend across the entire Universe:
the phenomenon for which we possess only one impoverished terrestrial word—
Intelligence.