- Physical preservation and integrity: Describes how much your immortal physical form will resemble your native biological form. It may be possible to reverse aging and give everyone the physique of a Greek god/goddess. Or we may become brains in jars. Immortality may be preservation, or it may require further evolution/change.
- Mental state preservation: Describes how much of your sense of self and mental dynamics are preserved. For example, all the information in your mind may be preserved, but is it accessible in a format that actually “thinks” dynamically, or is it simply subject to reading by computer without thinking? There must exist some range of possibilities. On one end your data is arranged and run in such a way that it mimics your mental processes, on the other end, it is arranged simply for information retrieval and is not setup for conscious recall or what we consider to be thinking. It may be possible for the latter to be reformatted and run for “awareness.” A separate but related concern: Can the human mind in its current form actually handle immortality? Our long term memories are terrible, and we get bored or stuck in routine relatively easily. Could ennui become the major risk factor for the continuation of our species, absent some way to modify our minds?
- Informational preservation: Describes how much of the information in your mind and body is preserved. Is the immortal you a direct copy or continuation of every connection and chemical in your original brain? Is it an “expert system” that mimics you to 99.99% accuracy? Are blanks and lost information filled in with algorithms that determine what most likely happened and which piece together your experiences accordingly? How much information is lost in the transition, how many transitions will there be?
- Continuity of experience: Describes whether the mortal “you” is the one that becomes immortal, or whether a copy is the immortal one—and the mortal “you” dies while the copy lives. Consider two scenarios: In the first, immortality tech consists of a destructive mind scan that kills your brain but reads all the relevant connections, chemistry, etc. necessary to create a computer emulation of your mind. Here, you will die but a copy of you will live on. In the second scenario, your brain is transformed neuron by neuron over the course of a year, replacing your organic brain with one made of silicon/ceramic/etc. During that year, the artificial parts of the brain continue to function precisely as the organic parts and interface with adjacent organic parts. This scenario appears to allow for total continuity of experience—the mortal “you” is transformed into the immortal you.
- Redundancies and backups: How many backups/instances are made of you, and how many of them are running/awake at the same time? Possibilities range from: (a) Singular individuality, where you are the only and unique copy, (b) serial cloning, where multiple clones of yourself live one at a time with frequent memory backups and with the next clone taking over when the current one dies, to (c) parallel cloning, where multiple versions of yourself are alive and aware at the same time. Option (c) eventually converges to (a), absent some kind of collective mind-sharing technology.
Technologies for immortality could be flawed, or particular strategies may only be viable for a limited period of time. There could be inherent deficiencies in an old method which must be overcome by a new one. Certain methods of preservation could be more prone to accidents and irreplaceable loss of information. Immortality may require a constant, shifting change and adaptation to new physical forms, new situations, etc. Evolution of the mind/body on the individual scale, facilitated by technology. The individual as his/her/its own species, eventually.
Mental state would probably have to vary. Expansion of capabilities over time. If the mind is preserved in a mutable form, can it be expanded and intelligence/capacities enhanced? Will sentience and sense of self be maintained, or could higher intelligence become unrecognizable to us? If not expanded or altered, how can a human maintain that they are the same person over the course of millennia? Can immortals remain sane given a human mind? How would one person handle 10,000 years of experience without either being bored with everything or completely forgetful of all but the last few hundred years? If the latter, is that person really the same individual that they were 5,000 years ago? Does it matter?
The societal implications of immortality are huge. If immortality is possible and it can be achieved while retaining power and influence in mortal affairs, then the rich and powerful will be the first to get it—and they will do their damnedest to make sure they’re the only ones who get it. Call them the First Wave. If they succeed, then we will be living under the thumb of a group of immortal, fabulously wealthy and powerful intelligent beings—effectively sentient corporations, or something close to that. Depending on how much they can insulate themselves from the results of their actions, the mortal population will experience one of two possible effects: (1) If the First Wave are vulnerable to violence or coercion, they will be forced to take the long view and be reasonably generous to mortals. Realize that they have all the time to the heat death of the universe to lose, while mortals have maybe 100 years. Under this scenario, it may be possible to extend immortality to the rest of the population if the rich/powerful immortals can be… persuaded. (2) If they are not vulnerable to attack, then it becomes very likely that the First Wave will come to see themselves as something akin to gods. Most people, given supreme power over others, are abusive when it is in their interest. Couple this tendency with a view that normal humans are like mayflies and you will have a future that makes Orwell’s 1984 actually look good. Under this scenario, the best hope is that the First Wave comes to benignly neglect humanity while going about their own affairs. Note as well that if the First Wave is not vulnerable to attack, it is in their interest to prevent any changes that may make them vulnerable to attack. Stasis is their preferred outcome.
This discussion does not include intra-elite conflicts within the First Wave. I suspect that there would be very strong taboos against killing others in the First Wave, since the downside of dying is so great. However, this leaves the door wide open to Cold War-style proxy wars that don’t directly touch the seats of power.
Assuming that immortality becomes available to everyone, what then happens to social progress? Imagine if a large chunk of modern day society consisted of individuals born in the 1300s. Does boredom eventually lead to experimentation, or to stagnation? What institutions are necessary to keep things running and moving? I would suggest that immortality requires that humans spread out quite a bit, to provide room for people to either experiment or grow bored as they see fit, without dragging everyone else along for the ride.