What is a human? In The Beginning of Infinity, David Deutsch describes one not as a walking animal with legs, arms, and a head but rather as something abstract — a universal explainer. It doesn't really matter how a human's explanations rise to the surface or whether they bubble up in silicon, flesh, or something else. It does matter, though, that humans create conjectures (ideas, guesses, stabs in the dark) that try to explain the world around them, which, in turn, get refined into new ideas. This unique loop of creating explanations, subjecting them to criticism, and picking up the remains to create the next round of ideas is what it means to be human.
This definition of humanity is maximally inclusive — are we humans? Yes. Can a computer, one day, become human? It seems the answer is yes. If so, the state of being “human” might be one that exists outside of (though it once emerged from) our state of being animals. Let's say that animals are creatures who evolve and reproduce through genetic evolution. Then, certainly, we are animals. Now, if humans are “things” that create knowledge and good explanations, it's clear that we fit the bill for that category, too. We are definitely animals, and we are definitely humans. But it's not necessarily the case that we are human only because we were animals first.
In Haruki Murakami's Kafka on the Shore, Kafka Tamura (who, as you may guess from the title, is the protagonist) runs away from home to escape his father and find his lost family. At one point, he says, “There’s no way to erase the DNA [my parents] passed down to me. If I want to drive that away I’d have to get rid of me. There’s an omen contained in that. A mechanism buried inside me. A mechanism buried inside you.” That mechanism — that’s the animal. The knowledge genes hold (how to grow, how to reproduce, how to heal) exists outside of our capacity to explain. We, like Kafka, cannot escape the rhythms of fate in our genes because what they contain is, for now, largely inexplicable. The moment we can have good explanations of how our genome works at a sufficiently fundamental level, we can begin to escape the “mechanisms” buried inside us. We will only achieve this escape through our capacity to explain, for good explanations are what precede progress. Deeper understanding paves the path ahead of us.
So if genes are inescapable even for us humans, what makes us different from other animals? We can imagine that general human knowledge falls into two (very) broad categories: genetic (DNA built up and refined through biological evolution) and memetic (ideas, concepts, and traditions created by thinking and refined by cultural evolution).1 Knowledge (of both kinds) comes into the world through conjecture and criticism. For genetic knowledge, genetic variations are like conjectures and natural selection pressures are like criticisms. As generations flow by, DNA gradually contains more and more knowledge because organisms evolve. This knowledge is abstract and general in nature — conjectures (i.e. mutations) that, on the surface, seem similar, may induce completely distinct behaviors and traits. Memetic knowledge also has this remarkably broad reach across domains. A meme, like a gene, is an abstract unit of knowledge. A gene can control one's height, emotional state, predilection for disease, or even capacity for glowing in the dark. Memes are just as diverse — the Ten Commandments, Curb Your Enthusiasm, Newton's laws, and liberal democracies are all sets of different memes that invoke different kinds of behaviors from us.
Okay, but what's the point of the distinction? Also, if both genes and memes evolve over time, what makes them all that different? Unlike genes, memes have to be expressed to be replicated. A gene only has one form — its physical representation in DNA — while a meme has two — its representation in our mind and its representation in our behavior.
If I think of a bad joke, share it with my friend, and see that he never shares it with another soul, it's clear that my meme died. On the other hand, if I think of a great joke, share it with a friend, and see that it goes viral (much like how a virus spreads through a population), it's clear that my meme was evolutionarily more successful. (For a very sophisticated illustration, look no further than this classic sketch.) But the critical difference here between a meme and a gene is that my great joke does not continue to spread across the population unless the behavior it invokes (laughing, retweeting, sharing) continues. That's why religions have such prescriptive and specific traditions — it's much easier to ensure a meme's preservation if you have followers physically enact rituals from a young age.
The notion that genes share this dynamic of constant expression or death is a bit absurd. It'd be like saying the reason giraffes have long necks is that when giraffes stretch their necks, their DNA changes slightly, and these changes get propagated down. Similarly, a mom may not have blue eyes, but that doesn't mean her kids won't. On the other hand, just because someone's grandma believed something doesn't mean that the belief somehow passes through the generations in her blood. Rather, each generation needs to pass on the belief lest it fizzles out.
Each and every day, humans create, contemplate, and criticize memes. Our DNA gives us the biological scaffold for this capability, but our genes themselves don't contain any of our memetic knowledge. And, looking back over the thousands and thousands of years humans have walked the Earth, what we consider as remarkable and distinctly human achievements have come through memes, not genes. Being an animal means containing, creating, and criticizing genetic knowledge. This is not a beginning of infinity because when I say “criticizing” genetic knowledge, I really mean dying and not spreading your genes. It's quite hard to “create” or “conjecture” new genetic knowledge if you're dead. As a species, we are able to conjecture and criticize genetic knowledge because the “thing” that's evolving and gaining knowledge isn't the individual — it's the whole species. Memetic knowledge, though, doesn't demand death or infertility as criticism. If my jokes suck, my friend can tell me that, and I won't collapse to the ground before him. If my ideas about the world are wrong, I can discover that through criticism and still live to think of new, hopefully less wrong, ideas. This is a beginning of infinity — I, and my fellow humans, can progress with no limit in sight.
As people, we are fallible — what we think of objective truth today will actually turn out to be bad explanations in the fullness of time — but we are capable of progress. Through memes, we can think of new explanations, criticize them, and gain knowledge without always putting our lives on the line. To be human, I believe, means to be active in this loop of generating memes (art, knowledge, ideas) and criticizing memes (dwelling on other people's ideas, extending them, shooting them down). An animal's identity emerges from their genetic constraints. A human's identity emerges from the breadth and depth of their memes.
W.B. Yeats said, “In dreams begin responsibility.” Thus, our responsibility begins with our power to imagine. Inverting a bit, we see that those who have the greatest powers of imagination are endued with great responsibility. Knowledge begins as imagination. When we look around and lose ourselves in wonder, when we ask questions of the void and seek within ourselves the answers, we are being human. Not just homo sapiens or people — humans.
Deutsch believes that all evils in the world emerge from insufficient knowledge. Before we had fire, we may say that the cold killed a vast swath of people, but in reality, it wasn't the cold — it was our lack of knowledge. Similarly, if we say cholera killed millions, we may as well say that our ignorance of germs and boiling water killed millions. If evil comes from a lack of knowledge, then morally good behavior is all about making more knowledge. Immorality preserves ignorance by preventing us from correcting errors in thinking.
In his wonderful lecture, The Morality of Fundamental Physics, physicist Nima Arkani-Hamed talks about how creating knowledge and enacting morally good behavior are actually self-reinforcing, like a flywheel. The very act of creating and criticizing ideas cultivates in us habits like 1) being honest, 2) sharing concepts freely, 3) rejecting lazy ideas, 4) focusing on someone’s ideas rather than “who” they are or which family they come from, and 5) searching for simple, deep truths rather than hollow, surface-level solutions. Why is it, then, that this process is so difficult? Why aren’t we all ground-breaking scientists living by this strict moral code?
Our lives are short, so we fear wasting time searching for a deep truth that may never emerge. Speaking about the 8 years he spent searching for his principles of relativity, Einstein said, “The years of anxious searching in the dark, with their intense longing, their intense alternations of confidence and exhaustion and the final emergence into the light — only those who have experienced it can understand it.” It’s through this deep sense of yearning, this blind search that we can glimpse a beginning of infinity. It’s as Ralph Waldo Emerson wrote: “Standing on the bare ground — my head bathed by blithe air and uplifted into infinite space — all mean egotism vanishes. I become a transparent eyeball; I am nothing; I see all; the currents of the Universal Being circulate through me; I am part or particle of God.” What better description than this of the morally good life?
When we stop seeking better explanations, we lose our humanity. We jump off the path of potentially infinite knowledge and instead cling to our memories. We abdicate the power of changing our fundamental memes and instead let them calcify. If we never evolve our memes over a lifetime, how is the knowledge they contain growing any quicker than our genes?
In Murakami's novel, Kafka grows close to Miss Saeki, a librarian who seems to live in the past. She “looks like a symbol of something. A certain time, a certain place. A certain state of mind ... while they're still alive, people can become ghosts.” When our memes become static, humans turn into ghosts. When we stop making progress, we are no longer human. Just as Miss Saeki's genes prevent her from growing to a height of her choice, her memes prevent her from living in the present. They deny her the essence of her humanity.
The beginning of infinity that gave us our humanity is elusive. The state of being human is not static — it calls on us to push forward, deepen our thinking, and correct errors, all under the pressure of limited time on Earth. In his final page, Murakami writes, “Time weighs down on you like an old, ambiguous dream. You keep on moving, trying to slip through it. But even if you go to the ends of the Earth, you won't be able to escape it. Still, you have to go there — to the edge of the world. There's something you can't do unless you get there.”
What is that thing? I'm not sure. But the act of going there, of looking for the elusive edge of the world? That's what it means to be human. And, like Einstein said, it may have to be experienced to be understood.
In between these two domains, the question of epigenetics rears its head. We've seen how memetic ideas and experiences — like trauma — may persist across generations even when their memory is forgotten. Does this disprove the distinction between genes and memes? I don’t think so. Memes definitely have impact on the way we evolve genetically, since they affect how we live and reproduce, and if that impact happens to extend to some peripheral facet of our biology, that’s okay. I still believe that human progress happens on a plane distinct from our genetic progress. I don't think this dichotomy is a religious or infallible boundary. Research in epigenetics and other fields may actually show that the line is significantly more blurred. That’s okay, too. However, I don't think we — quite yet — have very good explanations for how one's life experience changes our genetic material, if it does at all.