Fermi’s Paradox and Aristotle



Advanced technological civilisations would be impossible without an Aristotle and the host of haphazard historical circumstance that preserved his thought through the ages. Aristotle was the first real scientist. That’s because he assumed that in order to understand the world you must observe it, and that all knowledge comes from our senses. His notions contrasted with the notions of Plato, his teacher. Plato believed the opposite: that the world of the senses was an illusion, and that all there was to know was in the mind. For Plato reason came first and was adequate in itself. For Aristotle it was first observation, then reason.

Most of us know that Alexander the Great was a student of Aristotle. However, although Alexander admired his teacher when he was young, he became quite paranoid later and thought that Aristotle was plotting to kill him. Aristotle was very disappointed that Alexander declared himself divine; this was hubris in every Greek sense of the word. But Aristotle had another student too: Ptolemy, a friend of Alexander, then a general in his army and, after Alexander’s death, the king of Egypt and the originator of the Ptolemies, the Greek dynasty that ruled Egypt until its last queen Cleopatra killed herself as Octavian’s armies approached.

Ancient Alexandria

Ancient Alexandria

Ptolemy was instrumental in realising Aristotle’s scientific vision. He sponsored the founding of the Library of Alexandria, where all knowledge of the world was stored. And he encouraged scientists and engineers to explore nature. As a result, Alexandria became the scientific capital of the world. Some of the greatest scientific and engineering minds worked there. The influence of Alexandria across the Mediterranean was immense, and scientists started appearing in other places too, like Archimedes in Syracuse and Hypparchos in Rhodes.

The legacy of the Aristotelian Ptolemies passed to the Arabs who during the Middle Ages developed a rich scientific and engineering tradition, while Europe languished in Platonic introspection. Thankfully, in Renaissance, Europe awoke to Aristotle (St Thomas Aquinas played a major role in that), and that’s how the scientific revolution was made possible.

Perhaps therefore, we can now somewhat explain  Fermi’s paradox: life ought to be common in our galaxy. Evolution ought to have evolved highly intelligent creatures in several thousands planets. Why haven’t we heard of them yet? Why haven’t they discovered radio waves?

Assuming that their neurophysiology is comparable to ours (and that is a big assumption) perhaps they never had an Aristotle. They only had Platos. They exist, but have not discovered radio waves, have not built telecommunication antennae, or spaceships. The are stuck in endless, theocratic, Middle Ages.

Are we zombies?

What is the difference between thinking and appearing to be thinking? How can one tell them apart? An interesting answer comes from philosophy of mind in the shape and form of zombies.

philosophical zombie (or “p-zombie”) is a hypothetical being indistinguishable from a human but without conscious experience, or “qualia”. When pinched, a p-zombie will feel nothing but will nevertheless cry “ouch!” convincingly enough, so that we will be unable to tell the difference.

P-zombies have been used by dualist philosophers in their attacks of physicalism. Dualists believe there are two essences in the natural world, matter and something else beyond the scope of science. Physicalists hold the view that everything is matter and nothing else exists but matter. In the case of consciousness physicalists believe that our thoughts and feelings can be reduced to neurobiological interactions. Au contraire, dualists claim that consciousness is much more that the sum of biological pathways and brain states.

So let us imagine a hypothetical world of synthetic beings with artificial intelligence looking and behaving identically to us; a mirror world of artificial p-zombies on another planet or another dimension. Now say that something happens and while you were asleep you were transposed in that mirror world, whilst your double p-zombie was zapped over here, to our “real” world. When you wake up, how will you tell which world you inhabit now? And how will your friends and family tell that the “you” who walks down the stairs for breakfast is in fact a p-zombie from a mirror universe?

The answer to both these questions is the same: neither you, nor your family will know the difference.

In fact, both physicalists and dualists are at a loss in suggesting a way to distinguish the two world experiences. The former because for physicalists a p-zombie is impossible: as said, a physicalist believes that consciousness is the result of physical processes. If a zombie is the physical equivalent of a non-zombie, if every cell and function has been precisely copied in the zombie as is in the non-zombie, then there can be no distinction between the two.

A dualist will also be unable to resolve your conundrum but for a different reason. She will not have any test to offer that may tell which world is the real one and which one is the zombie-world. Such “test” would require third-person verification, i.e. some objective measurement of “something”, in other words it must be a scientific test. But dualists believe that the extra essence that separates real beings from zombies is non-physical and therefore impossible to measure by scientific methods.

Whichever you look at it you may never know if you now inhabit a zombie world or a world of “truly” conscious beings.

This rather unnerving realization leaves you with the only question that you can seemingly answer in the positive: are you a zombie? Of course not, you may hasten to answer.

But let’s look at your answer somewhat deeper . In answering “of course not” you are in fact asserting your inner experience of “being somebody”, your so-called “self-awareness”.  Of course, as far as we, your listeners, are concerned we must remain unimpressed by your answer. We can neither trust your answer, nor the way you look or behave, because for all the reasons I explained you could be a zombie pretending to be a real human being.

Maybe, for exactly the same reasons, you should be skeptical of your answer too!

For, how do you know that your so-called “self-awareness” is not an artificially programmed agent which when triggered by the question “are you a zombie?” returns the answer “no”? What if this agent while answering places a memory in your artificial memory banks of having just answered the question, thus creating a feedback loop which you, rather arbitrarily, call “self awareness”? What if “you”, your “inner experience”, your “memories”, are programs? What if “you” are the multi-agent, artificial being from the mirror world of p-zombies, which slipped into our “real” world?

Metaphysics explained

The term “metaphysics” owes its origin to one Andronicus of Rhodes who lived at around 100 BCE and was an editor of Aristotle’s corpus. Aristotle had something to say about everything and Andronicus was soon confounded with an editorial problem: how to discern the great philosopher’s early works entitled “Physica” (physics) from the ones following it.  Unpretentiously, he used the term “Metaphysica” which simply means “the ones that come after physics”. And thus “metaphysics” was born.

In Physica Aristotle enquired upon the nature of things, for instance why some things fall (e.g. rocks) while others rise (e.g. smoke). In Metaphysica he addressed more general questions like what are the basic elements, he critiqued Democritus’ atomic theory as well as Pythagoras’ core idea that everything is ultimately made of numbers, and he discussed – but mostly rejected – Plato’s views which were in many ways similar to Pythagoras. He also theorized about the nature of causes (causality) and pondered upon ontological semantics – what it means to say that something actually exists. Aristotle considered his entire corpus as a concise study of nature and never differentiated between “specific” and “general” questions. For him nature was a seamless continuum.

Nevertheless, his successors many centuries later made the distinction between “physics” and “metaphysics”, the former being the experimental study of nature while the latter the probing of what was beyond the scope of science. So what is the study of metaphysics now? Its domain shrinking as the various scientific disciplines mature, metaphysics is very much in doubt. Most scientists do not think that there can be something in nature resisting the application of the scientific method. Unexplored areas such as dark matter, string theory, quantum gravity etc., although still beyond experimental scrutiny, are not considered metaphysics; they are falsifiable scientific hypotheses, and as such fall well inside the “Physica” of the 21st century.

Nevertheless, there seems to be one last bastion of metaphysics that still holds: consciousness. The epistemological problem with consciousness is that it cannot be measured objectively. Measuring instruments currently available, such as PET or fMRI scans, can really “see” inside a thinking brain and produce bundles of amazing images. Those images however must be corroborated with what the person in the scanner felt or thought at the time of study. In other words the experimenter needs the subjective report (the person describing their experience) of the experimental object (the brain inside the person) in order to validate her results. There seems to be a disturbing gap between the object (brain – third person reporting) and the person (consciousness – first person reporting), that is apparently unbridgeable.

As a last bastion of metaphysics consciousness is a serious one. Consciousness underpins all measurements and, therefore, all of our science and all of our knowledge. We know what we know because we think that we do. If science proves unable to incorporate consciousness in its corpus then we must remain forever skeptical about the nature of our universe and of ourselves. This amounts to a bomb ticking at the foundations of all natural sciences.

In this light, Artificial Intelligence aiming to reproduce consciousness in a medium other than a biologically evolved brain is a heroic attempt to save science. A thinking robot will not be a simple curiosity but indisputable proof that consciousness belongs to the material world.