The march of technology turns matters of philosophy into matters of practical action. The process of taking visions and making them concrete makes once airy hypotheticals relevant in everyday life. The theoria of the ancient Greeks becomes praxis. What if I could talk to my compatriot now journeyed to the far side of the sea? What if the years of men and women were not limited as the gods decreed by way of the example of Tithonus? What if I could see the very smallest building blocks of the stones and the plants? How could a city of ten million ever be governed? How would men and women live were there not the need for near all to work the land? This process continues today, and at a much accelerated pace as new capabilities emerge with each passing generation. A transition lies ahead, however. Some of the new technologies of the rest of this century will be different from those of the past in one very important way: they will allow the human mind and human nature to be changed, to be copied, to be reconstructed in software and machinery other than that of our present biology. This prospect gives weight to a range of important philosophical questions both in the futurist community and among those who carry out practical work that contributes to this future.
The question for today is this: is an exact copy of you also you? As a consideration, this is of absolutely no practical value to most people today - unless either (a) you happen to think that the Many Worlds interpretation of quantum mechanics likely reflects reality, or (b) you are signed up for cryopreservation as an end of life choice. Even then only the latter group might choose to do something as a result of having a position on this topic. The reason that this question and the voluminous philosophical discussion surrounding it are of limited perceived value to the average individual is, of course, that we cannot create copies of people. Not now, and not for a few decades yet. Most of those reading this now in 2016 will, however, live to see minds copied. Reverse engineering the human brain seems to be to be the most plausible road to the creation of artificial general intelligence. Unlike the other approaches, it quite clearly requires only the combination of sufficiently large amounts of processing power and sufficiently good understanding of the molecular biochemistry of the brain. The more of the former that is in hand the less of the latter that is needed, but both of these areas of human endeavor are moving forward at a fair pace. Praxis will start with tentative running copies of scanned neural architecture in the laboratory, and from there the process of research and development will be driven ever faster. The advantages inherent in being able to create new economic actors with a fraction of the resources needed prior to that point are enormous, and the societies that embrace this technology will dominate. By that time a position on whether a copy of you is also you will be a very necessary thing, and I don't think this is the far distant future we're talking about here. Once this revolution is well underway, and driven by economics, individuality will start to fray at the edges, and those who are comfortable with that fraying will take full advantage of it.
That is the future. But people who are signed up with cryonics providers really do need to have a position on this question now. The cryonics community is quite divided between those who believe that a copy of their preserved brain, running as an emulation, is a quite satisfactory form of survival, and those who want their original biological architecture repaired and restored. That all hinges on what you think about the ontological status of an exact copy of you. If rejuvenation research fails to deliver in time and you are forced into cryopreservation as the only viable backup plan that offers a shot at life again in the future, then your only defense against someone choosing to scan and emulate your mind - discarding your vitrified flesh along the way - is to request that this not happen. If you don't express a preference in a way that will last (a metal plate under the tongue?) then you are taking an additional chance on how the winds of culture and preference will turn in the years ahead. The part that concerns me is the economic angle I mentioned above; that it seems plausible that tremendous advantages will accrue to those who chose to abandon the concept that individuality is tied to matter and state, and instead become comfortable with both copying of the self and radical alteration of the mind from moment to moment.
As a longer examination of this divide insofar as it applies to cryonics today, I'll point out the article linked below, published earlier this year. I think the author doesn't quite get the division of views right, but it remains an interesting read. I'm a reanimator in his taxonomy, but certainly not possessed of any vitalist ideas about the necessity of a biological substrate for the human mind. It is perfectly possible to consider that the data of the mind can and will be copied and run in software on a practical basis, and still be quite attached to this present instance of the self, associated with its present set of matter, considering it a distinct and different individual from any hypothetical copy, running on a different set of matter. This instance of me is the self, the one that needs to survive for there to be a point to this exercise: the pattern that matters is this slowly changing set of atoms that moves forward through time with no major discontinuities. I might be generally well inclined towards a copy, should such a thing come to pass, but then we all tend to be generally well inclined towards people who share our views. That is about as far as it goes.
People who are at least a little bit intellectually curious about making the brain preservation choice at the end of their lives are a small but growing demographic. It has been estimated at 1% of the population of most developed-world societies, and a likely smaller fraction in traditional societies. That's a small percentage, but a large number of individuals. We can also expect this group will grow as the cost and accessibility of brain preservation drops, and as validation that preservation preserves retrievable memories (and perhaps more) in animal models grows. The currently preservation-interested demographic can be easily divided into three camps, each with different expectations for the future. The folks in each camp don't always understand or talk to each other all that well, but they need to learn to get along. You'll probably grant that at some point in your future either you or your loved ones will find yourself contemplating, at least briefly, the major life choice of cryonics. Having to think about this topic may even happen earlier than you expect. Death has a way of surprising us.
Camp 1 - Reanimators
Reanimators either desire, or expect it will be necessary, to repair and reanimate (bring back to life) themselves in the form of biological bodies, in order to live again. They believe or expect, with a greater than 50% probability (and for some, essentially 100% probability), that their personal identity (personality and self-awareness) arises out of the unique physical and informational features of biology. Thus they think human minds need to be biological in order to exist. Reanimators hope to perfect a technology some call "reversible solid-state suspended animation," the ability to cryonically preserve and later reanimate human beings and brains. That is an exciting vision, and we can certainly expect some progress on that front. There are numerous examples of the new tissue and organ preservation strategies being tried in labs around the world, with the near-term goal of expanding tissue and organ banking in medicine.
Camp 2 - Uploaders
Uploaders are "patternists," meaning they believe or expect, with greater than 50% probability (and for some, essentially 100% probability), that the functional abilities (informational and computational patterns) of their biology are their true self, not their biology, which presently carries that pattern, and not their matter either, which changes constantly during their lives. Another way of defining an uploader is that they believe or expect that there is less than 50% probability that repair and reanimation of their biology or their matter will be necessary in order to wake up in the future. They expect instead to be scanned and uploaded, and wake up as a technological mind, inside some kind of technological body, in a future environment. This brain scanning and uploading technology is already much farther along than most people think. For example, neuroscience labs around the world are already using automated FIBSEM machines (a kind of electron microscopy) to scan and upload into computers detailed connectomes of small animal brains, including flies, zebrafish, and even parts of mouse brains. We don't yet understand how to read memories from these digital connectomes. But give it a little time.
Camp 3 - Uncertains
Uncertains as their name implies, don't yet buy the arguments of either of these two camps, which puts them firmly in a third camp. They talk about cryonics and brain preservation as an "experiment" or a "bet" that they'd much rather make, given the alternative experimental groups, that of either certain death or a religious afterlife. If asked, they might put the odds near 50/50 for reanimation being necessary for them to come back, or simply unknown. Some uncertains will grant that neuroscience and computer science now argue that human memories are stored in a small set of stable molecular features (most importantly, dendritic spines) in neural connectomes, and that if these are well-preserved at death, then our life's memories can very likely be scanned and uploaded to future computers, to share with our loved ones or the world. But they are typically agnostic on the question of whether all the brain's functions, including emotion, personality, and consciousness, are substrate-independent.
The Transporter Test
A good test of whether you are a reanimator, an uploader, or uncertain, and whether you have an instinctual bias to reanimation, as most folks do when they first engage with these ideas, is to ask the Transporter question, a test that uncovers your assumptions and biases with respect to the copy problem. Would you go through a Star Trek transporter (molecular scanner, disassembler, pattern storer, information beamer, and reassembler, using new molecules) if many others had done it, and claimed to still be themselves on the other end, and as far as you could tell they seemed the same? Or would you not go because you presently believe the process would cause your own death as your brain was being molecularly disassembled, and you believe your reassembled brain and body would be just some kind of unacceptable copy that only "thinks" it is you? This is a really deep question, and it depends on your view of the nature of personal identity. Consider that all three responses to this test are valid, from the point of view of members of each camp. If such a device were created, all three mental attitudes would be common, and all three would be socially reinforced as the right choice, by the members of each camp. So it should be obvious that each camp needs to learn to get along better, right?