Till Nikolaus von Heiseler

A meditation on personal identity

“We are going to die, and that makes us the lucky ones.” This is the stunning opening line of Richard Dawkins’ most philosophical book Unweaving the Rainbow (1998). He then adds: “Most people are never going to die because they are never going to be born” and he shows how unlikely our very existence is. The potential people that could have been here in our place outnumber the atoms in the universe. “Certainly, those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I that are here.”

If I ever wrote an autobiography, I would start with the description of a serendipitous accident: my conception. An unexpected knock at the door, a divergent movement of my future mother, an aberrant thought in the head of my future father, all of this would have quashed my life before it had even begun. And none of the unborn are even given the chance to complain; because nobody can complain about their own nonexistence. Now, bear in mind that the lottery started even before we were conceived. “Your parents had to meet, and the conception of each was as improbable as your own. And so on back, through your four grandparents and eight great grandparents …” All back to the beginning of life, to the first self-reproducing molecule that emerged on this planet about four million years ago.

Be that as it may, this is just the first dimension of the wonder of being– there being at least two of them. I wonder which wonder you wonder more about (and which bemuses and confuses you more): the paradox of our existence or the hard problem of consciousness. Both are related to the wonder of being alive. Let me test you now – to find out who you are: Are you more of a poet, or do you have the soul of a scientist? Which of the two wonders takes your breath away?

In the first wonder, the word wonder means that we are indefinitely improbable. There is a charming twist to this: If determination is not true and chance really exists – say on the quantum level – everything that actually exists must be infinitely improbable. This at least is true if time is a continuum and there are therefore countless points in time where things could have gone differently. But is infinitely improbable not also the same as not possible? At the same time, anything that exists must be possible (p ⊃ ◇p). We shall call this the paradox of our existence: we are something that is incredibly unlikely to be.

The paradox of our existence is hard to grasp. However, it is not impossible if we find refuge in an (anti-Einsteinian) analogy: Imagine trillions of dice (marked by numbers) being thrown. Now, any particular outcome is very unlikely, but when the dice are once cast, the actual (everything that is) is the actual – no matter how unlikely it was before it was realized.

Nevertheless, some people would say that with this train of thought we did not even travel through the landscape of the wonders of our existence. Why are we here? Why do we have consciousness? Why can you read this sentence and at the same time know that you are a person? This brings us to the second meaning of wonder: the wonder of being aware. Are you ready to enter the gates of the unknown that are headed with the engraving the hard problem of consciousness? This will transgress what we called the paradox of our existence earlier. – Why and how?

If the wonder of life is greater than the paradox of our existence, and the paradox of our existence means that the chances we would ever exist are almost zero then the wonder of life must be greater than the improbability that something genetically and physically identical to you (including, but not limited to yourself) ever emerged. Or to put it in a simple question: Could we be genetically, physically and psychologically – with all your personal memories – the same as we are and still not be the same person?

This can be shown by a thought experiment introduced by the English Philosopher, Derek Parfit, presumably inspired by the American science fiction television series Star Trek. Imagine you will be teleported form the Earth to Mars. You have already done the journey once or twice and there have never been any difficulties. There was no headache, no jet lag and no memory loss. The teleportation, as you learned at school, first puts you to sleep, and then scans your elementary particles while breaking you down into atoms. This information will then be relayed by electromagnetic radiation to Mars, where another machine re-creates you using the local elements. Every atom is in exactly the same state and the same position as it was before. Because materialism is true, the same physical state will create the same psychological state. You can also remember everything, and you are still experiencing flatulence from the Indian chickpea meal you had yesterday. Furthermore, your thoughts continue where they left off, and you can even continue drafting your new paper on personal identity in your head. And – wow! – it is so fast: instead of traveling for over a year, it only took you somewhere between 4 to 24 minutes (depending on positions of the planets in their orbits). These are the advantages of travelling at the speed of light!

Now, a new generation of teleporters are in the Beta-testing phase. You can travel for free and, even better, it is completely safe, much safer than the older machine because your body is only destroyed once your information has arrived at its destination and the atoms are reassembled and double-checked. How great is that?

However, a technical problem occurs. You wake up and you are not on Mars as you had anticipated but you’re still in the teleporter on earth. Now, you open the door of the machine in anxious confusion. You step outside. And there she is again. The scientist in a white smock you had just been talking to. You only see her back and she seems busy. Is this a dream? “Hello?!”
She turns to you like a child that was caught at a private moment; and now you remember her name: Dr Elvira Kolerova. She stares at you with her green eyes and then whispers with a slight Russian accent: “What are you doing here?”
“That is exactly what I would like to know!” – and you explain what happened to you. She nods, checks her monitor and tells you politely that everything went completely fine. The information was transmitted, and you were rebuilt on Mars. “Here,” she says with a gentle rolling r, “take a look! There you are.” And you see a person identical to yourself on the monitor. “You are already there, this is you on Mars.”
“Hm!” You think and rub your forehead.
“You have definitely travelled to Mars. Everything will be fine. There was only a tiny problem: you woke up and left the teleporter where your old body should have had been destroyed. There was nothing wrong with the machine. Only the sleeping pill did not work properly.” and that, she tells you, was not her mistake.
“I see.”
Now she explains to you how the problem emerged. “Think of the teleportation as a process of relocating data onto another hard disk. Relocating includes two separate steps: copying and deleting.” And she calmly explains to you that the deleting will be done in about ten minutes. … Uh – really? You mean you will kill me? … In this moment you realize that you are not the person you thought you were. You have only existed since the last teleportation back to earth in November two years ago. Your original self is long dead. But actually, you do not care too much about your original self and also not about the other copy of yourself on Mars. You care only about yourself because you have your consciousness, you experience the world with your senses, and this is just how it feels to be alive.

You take a deep breath, as if this could help you understand what it means to exist. But it doesn’t. You take your hands and grope your face. For a moment, you feel like you are just on the verge of knowing what existence really means. This is the meaning of life, this very moment. You reach for the truth – but then you lose it all again. You think about it: We will all be dead. And there will be nobody to remember us. The sun will grow cold. The universe will end and may start again without us, this intelligent and vain animal on the blue planet in one corner of the universe. There will be nobody who will write a requiem for our kind. However, we can reflect and experience. This is the beauty of our existence: thinking about why we are here, reading great poetry and scientific theory on how we came into being, thinking about evolution and about consciousness. We are the lucky ones.