While discussing my ideas about identity with a friend, it became apparent that I hadn't delved sufficiently deeply into the existential consequences of cloning yourself body and mind. This friend appeared to agree with me on most of what I had written, but when I proposed a new thought experiment to him, he came to very different conclusions to me.
The thought experiment is simple enough, and asks whether you have any interest in the welfare of your clone should you clone yourself.
To make it a little more concrete, let's look at a semi-realistic example. Suppose the government proposes to send a colony ship to spread humanity to some remote planet which we have found to be hospitable for human life.
Starting a colony might have a great number of difficulties. It may be difficult to find enough volunteers to set up a self-sustaining civilisation on a remote world. It would certainly be costly to sustain and transport all the volunteers for the duration of the vast journey across interstellar space.
And when the colony gets there, they will find a virgin planet that is not yet ready to support them.
Thankfully, a technology of whole body and mind cloning could help to solve these problems. Suppose that once scanned, all the data that describes your body and mind can be stored digitally and physically created at a later date. All we need do then is to transport or transmit these digital copies across space, along with the cloning equipment. We can physically create the bodies on the other end as they are needed, ramping up gradually over time as the developing infrastructure becomes capable of sustaining more and more people.
This also partially solves the problem of separation from loved ones. Those left behind are no longer effectively bereaved, as only clones are sent. Of course the clones may not be happy to find themselves materialising on another planet without their families, but this brings me to the point of the thought experiment.
If you have a set of valuable skills and the government is offering substantial financial incentives to you to participate in this endeavour, but you would really hate to be separated from your family, would it be rational to let them clone you?
My friend has no qualms about using a teleportation system which works in precisely this way but involves the instantaneous destruction of the original. My friend also believes it would be perfectly rational to participate in this government program.
To me, these two views are radically inconsistent. I would happily use the teleportation system, yet I certainly would not allow the government to clone me. This is because in both cases I identify with the clone. If I am not willing to accept interstellar transplantation, then I will do whatever I can to prevent having a possible future history where that occurs.
In the case of teleportation, only one future self is possible. The "original" copy is destroyed instantaneously, and so never realises an independent identity. The only remaining possible future is the one where I have been teleported. As such, when I step inside the teleportation machine, I should expect to be teleported.
In the case of cloning, I have two possible future selves at the time I make the decision. One future self remains on earth, while one finds himself suddenly on an alien world with all he loves on earth forever out of reach. Therefore, when I step inside the cloning machine, I should expect to experience a 50% probability that I will remain on earth, and a 50% probability that I will step out onto an alien world, centuries having passed in what felt like an instant.
It is therefore irrational to participate in the project unless you can accept the risk that you will find yourself transported.
My friend defends his viewpoint with the argument that since he steps into the cloning machine on earth, then why should he expect to step out on an alien world? Surely that would be some other person, albeit one who is identical to him in every way and shares his memory.
True, from the point of view of someone who has just stepped out of the machine and remains on earth, that person who will some day materialise on Sirius IV really is a different person.
But from the point of view of my friend making that decision, both the earth self and the colonist self have precisely equal claim to my friend's identity. My friend is just as different in mental state from the earth self as he is from the colonist self. If he can identify with the earth self, he can identify with the colonist self.
It's like a road with a fork. Do you go left, or do you go right?
The only way I can see a justification for attaching some special connection to the future self on earth is if what we identify with is physical, but on previous blog posts I have argued why that cannot be the case.
What we identify with is the mind, and the mind is not material. It is not fundamentally tied to one place or time, although it is tied to a single brain in practice. This would no longer be the case if this kind of cloning technology were possible. A cloning operation would be a bifurcation of a single mind into two, the way a cell splits in two. Both child cells have equal claim to the identity of the parent cell.
This becomes more obvious if we imagine that the body has to be destroyed in the process of scanning, but is immediately reconstituted once scanning is complete. In my view this is perfectly compatible with the original framing of the question, at least if teleportation is acceptable. After all, if my friend accepts teleportation, then he is already comfortable with being destroyed and rebuilt without having any existential crisis of identity.
As such, we should in my view be just as concerned about the welfare of the clone as we are about the welfare of the original. Even the terms "original" and "clone" are problematic, as one is not more authentic than the other if the cloning operation is perfect. There is no original, there is no clone. There are only your two future selves.