Shaun asked:

Regarding existential dread/ depression.

I am a big fan of being alive. I love life. And as such, I would like to never die. I’d like my wife and children to never die too. And you, and the person sitting next to you. The idea of a person, a mind, escaping existence, is horrifying.

And so, I feel this existential dread. I feel that all I’ve lived for, all I’ve valued, is without purpose, because in the end, I’ll die.

If I could, I would just accept it. I’m really good at accepting reality, even when it’s painful to do so. And that would more or less solve my problem.

However, given the successes of modern science and medicine; given my understanding of biology, the brain, and the mind; I don’t accept that death is inevitable.

I know, it sounds like denial. But look at the success of science and medicine. From cloning to artificial hearts. 1000 years ago, it would have been considered magical thinking. It would have been regarded as denial.

And so, that’s where I am today. Whether through biological or electronic, or some new technology, I believe that immortality of the MIND is possible. And so, I can’t simply accept that I’ll one day die. Which leaves me vulnerable to the despair I often feel.

How do I grow through this? I wish I could just accept death and be done with it, but I can’t seem to do that, when the potential for immortality is so incredibly close.

Of course, you may not agree with my assessment of technology and medical science, but, assume that I very much do, and that this is part of my problem.

Answer by Geoffrey Klempner

I know exactly what you mean, Sean. To cease to be is a horrifying prospect, and yet it is a prospect we all face — or is it?

On this question, scientific speculation cuts two ways. According to one cosmological theory, the universe will end in a Big Crunch in which every finite entity will be destroyed. So, on that hypothesis, your life may be extended far longer than a natural human life, but you will most definitely die. Your prospects are no better according to the theory that the universe is inevitably tending towards a state of maximum entropy when all chemical processes will cease.

Theories can be wrong. Maybe these theories are wrong.

Leaving questions of cosmology, there seems to be no ‘in principle’ barrier to the indefinite extension of human life by some technical means or other. The problem is that the assumptions that you would need to make to allow indefinite life make it just as likely that there can be any number of ‘Shauns’ produced by a cloning/ copying process. To keep Shaun’s brain functioning, the information has to be copied and saved, maybe uploaded onto disk and downloaded into a fresh brain — or brains.

Maybe you are not the original Shaun but a copy (your home CCTV reveals the original Shaun being kidnapped and a Shaun-copy substituted in his place). By hypothesis, your mind is qualitatively indistinguishable from the mind of the original Shaun. You say you absolutely know that you are the real Shaun, but the other Shaun (or Shauns) vehemently contradict you — even your wife and children are unable to tell you apart.

The notion that, ‘I know where I will be’ is very powerful, and yet it succumbs to standard thought experiments on personal identity. You go into a body-splitter and two Shauns emerge. You say you ‘absolutely know’ that if you find yourself standing on the left then the Shaun on the left is the ‘real’ Shaun, but the Shaun on the right believes precisely the same thing. You can’t both be right!

If you can’t be both ‘Shauns’, then you are neither. Irrespective of whether body duplication ever becomes a technical possibility, there is no ‘mental entity’ that persists from one moment to the next, in the way that your body does.

‘But what if I have a soul?’ — What difference would it make if your so-called ‘soul’ came into existence one second ago? What difference would it make if there were a hundred ‘souls’ inhabiting Shaun’s body? Souls can’t be counted, you can say what you like about your ‘soul’ and not be wrong, because nothing can contradict you. Your subjective experience from moment to moment remains the same, regardless.

You may reply that no thought experiment or clever argument can convince you that your subjective sense of self or soul is not the same entity that began reading this answer a short while ago. But here’s the thing. If you really think that, against all argument, then everything is fine because even if the universe ends, it is still possible that you will survive. Maybe as a spirit floating in empty space. In infinite future time, anything can happen, right?