Is the person sitting next to you a human being? The question hardly makes sense; how could she not be human? Yet in the coming years the question will become commonplace, even urgent.
For the humanist, the topic is absurd, offensive. All people are equal; denying humanity to any group leads to oppression; we have the same fears, bodies, and aspirations as the Greeks 2,500 years ago, or the Egyptians 5,000 years ago. Culture changes, the world is shaped by technology, knowledge grows – but humans remain the same. My children, and my children’s children, will be the same as me. How could you possibly imagine otherwise?
In the purely physical sense, our genus Homo has had a run of about 2.5 million years. Before that, there were no human beings, though evolution was winding its way towards us, with Australopithecus. Our current form, the knowing one, sapiens, didn’t arrive until about 50,000 years ago.
These distinctions are of recent origin, however. Linnaeus coined the term Homo sapien in 1758. Before that, in the time of Shakespeare, who were you likely to meet in a dim alley? Djinns and apsaras, titans and gods, fairies and phantoms, unicorns and genius loci. We shared the globe with many beings, and shape-shifting was a given; the person next to you might be Zeus in disguise – or that laurel may have once been shy Daphne.
But let us set aside myth and religion, and walk into the modern light of reason. Backed up with a few centuries of anatomy, paleontology, chemistry, and genetics, can’t we defend a simple statement about what constitutes a human being? Yes and no. The very notion of species has been debated since its inception – is it a matter of form? Function? Genetic structure? For all its explanatory power, evolution is a complex science, itself growing and changing.
“Things that think” seem to be increasingly appearing, driving our cars, sorting lists, booking the best flight. Mere algorithms, instructions in deterministic machines? And what are you, Homo sapiens, that distinguishes you from such a machine? Perhaps you are mere molecules and electrical signals, the rush and sweep of chemistry. If not, where is the ghost in the machine, the soul in the body?
In cultural terms, the question remakes itself every day, like the mysterious shroud of Penelope. Perhaps a human being is one who uses symbols, who thinks, meditates on time and self, or creates abstractions. The problem with these touchpoints is that year by year they are being encroached upon by computers, which can now play chess, recognize faces, check spelling and grammar, recognize patterns among cancer cells, even prove mathematical theorems much faster that you. We move the goalposts every time that the Team Algorithm wins another game, but the end is nowhere in sight.
What about the pinnacle of humanity – the genius? Those who see visions and beings, smell colors, ride with light waves, hear entire symphonies in a second seem to be another type of being. Where do we place Blake, Einstein, Nabokov in the scheme of things? They can appear frighteningly different to the average person, and history has not always been kind to the genius or synesthete, or treated them as “one of us.”
There are those who seem to pass over further thresholds, travelers to another realm altogether: Jesus, Buddha, Mohammed, Blake, Ramakrishna, Aurobindo. Are they human, or do they transcend our species? And if so, where is the boundary, where the line which separates the mundane from Otherness?
These questions are converging. Philosophy, religion, metaphysics, and cognitive science are going to be the bread and butter conversation of every breakfast table in decades to come. As brain-computer interfaces come into use, mental and inner life is going to be stretched into dimensions hitherto unimaginable. Even simple technologies like augmented reality goggles will shift our perception of others. Individuals like Oscar Pistorius will run without legs, even as Stephen Hawking talks without a voice.
Then there is germ-line engineering, changing the characteristics of future generations.
In other words, altering what makes us human.
In 1990 Dougal Dixon, a Scottish science writer who specializes in evolution and biology, wrote Man After Man: An Anthropology of the Future, in which he looked ahead 5 million years, postulating where simple biological evolution might take our species. In addition to being an excellent introduction to evolution, it is a profoundly disturbing book – because we see on every page different directions for our family tree: into the water, onto the savannah, into space. Speculation, yes – but the biological revolution has already arrived, and synthetic biology sets can be purchased on the net. Just last week Stanford produced the first complete model of an entire organism, down to the level of chemical interactions. The tools are within our reach.
The question is not whether people will modify their chromosomes, but when.
Tempting though it may be, either/or distinctions are not that helpful. J. Storrs Hall, in Beyond AI, uses Greek prefixes to categorize machines who think. He distinguishes among those that are not as smart as us (hypohuman), which characterizes most machines today. Then there are those passing through (diahuman), “where AI capabilities are crossing the range of human intelligence.” Depending on what you think defines humanity (playing chess?), AI may be approaching this stage even today. Many researchers think that AI is likely to be strikingly different (allohuman). If the exponential curve keeps rising, once AI hits the human level, it will move beyond it, into what Charles Stross calls “weakly godlike,” where such an entity could, for example “read an average book in one second with full comprehension” or “take a college course and do all the homework and research in ten minutes.” We’re moving beyond the range of what is comprehensible here, gazing into the eye of a whale, whirling within a black hole.
And then there is the far country, what Nick Bostrom calls superintelligence, Vernor Vinge calls powers. In terms of intelligence or productivity, such a being might “be productive, intellectually or industrially, on the scale of the human race as a whole.” Comprehensible, perhaps, but just barely. Will there ever be such beings? Will they arise through technology, biology, or some third means as yet unseen?
In 1935 Olaf Stapledon published Odd John, a prescient story about a strikingly different boy. John’s qualities are mental: telepathy and superintelligence. Ten years later he published a story about a dog named Sirius who reaches human intelligence. Stapledon’s writings set the stage for later meditations on human nature and the future, such as Clarke’s Childhood’s End and Lem’s Solaris. Borges said of Stapledon that “he pursues and retraces the complex and obscure vicissitudes of his coherent dream.”
Stapledon was seen as a philosopher; that was before futurist became an accepted job classification, and before computers, genetic engineering, and nanotechnology became practical engineering tasks. Today’s programmer may be tomorrow’s applied theologian, striving mightily to reverse engineer the doings and thinkings of hyperhumans.
In More Than Human, Ramez Naam says “We are not the end point of evolution – there is no such thing. We are just an intermediate step on one branch of the tree of life. But from this point on, we can choose the directions in which we grow and change. … At some point, one hundred years or one thousand years or one million years from now, our world and perhaps this corner of the universe will be populated by descendants whom we might not recognize. Yet they will think, and love, and dream of better tomorrows, and strive to achieve them, just like us. They will have the traits most dear to us. They will be different in ways we cannot imagine.”
The question of what makes us human, and what we share as a thinking dreaming species with other entities, will exercise us for years to come.