X-Message-Number: 21746 From: Date: Sun, 11 May 2003 16:33:48 EDT Subject: Re: CryoNet #21736 -qualia etc I think it is very important for cryonicists to create and widely disseminate what I would call "plausible paths to the future," and it was in this connection that I found Francois' 'thought experiment' provocative. Here are some of my thoughts. It occurs to me that the general setup for Francois' thought experiment roughly describes what actually happens to the cells of the human body as we live out our lives. Individual cells divide regularly on a program provided by our DNA while many cells are actually dying, being replaced by the newly divided cells, on and on. The process is most obvious in the skin and corneal epithelium where cell layers continually move up the line, changing position and function in an orderly layered way, on their course toward devitalization and sloughing off, but the same general process takes place throughout the body. It is least obvious in the brain and neural network where it seems that some cells evolving from before birth stay in place throughout life but neuronal cells do divide and, in effect, get replaced. Ongoing research with stem cells is clearly aimed at developing a rejuvenation process whereby old and damaged neuronal cells are replaced, perhaps a few at a time, restoring lost or deteriorated function. When such new growth, or in the case of limbs, at least, regrowth, takes place, the question of identity is not likely to come up. Recovery is presumably seamless if relatively small numbers of cells are involved, less so if whole sections of the brain are replaced with new tissue, emerging perhaps in some tabula rasa fashion. Moving into the more distant future, however, we can reasonably speculate that such cell replacement will be managed as a continuous process in which consciousness is not interrupted at all, even though, over the course of let us say 50 years every single original neuronal cell is replaced. Surely this is the direction in which we cryonauts hope medical science and anti-aging science is taking us. I believe that the first semi- immortals will evolve in just this way, through an entirely organic process which may not involve nanobots at all nor electronic prosthetic devices of any kind, but will allow life extension into hundreds of years or more. Will the 50 year old person be the same as the 100 year old or the 200 year old? Yes, I am sure of it, because, despite their replacement parts they will experience their lives as one long flow just as we do now. Of course, our experiences over all those years will change us, perhaps radically, just as we change now from childhood to youth to adulthood to old age, and we are often at a loss to say if we are REALLY the same person we were before. OK, given that scenario, what about Francois' thought experiment with nano devices or whatever? We already have a lot of experience with prosthetic devices, some attached to us, some not. We could even think of the automobile as a prosthetic device which allows us to get around much faster and in full bodily comfort. Some of us also have internal devices, heart valves, hips, pacemakers, etc. There may come a day, I think long after we have achieved organic semi-immortality, when we will find it desirable to integrate nanobotic devices to our brains and bodies to do all sorts of things which our organic brains can't do as well. Then we can begin to imagine a replacement scenario such as Francois poses, and as it proceeds we can imagine that it might go as far as total replacement. Why we would choose to go so far down this road isn't entirely clear to me, but I am sure that no sane human would trade off qualia for mere functionality unless, by so doing, the remaining qualia are thereby remarkably enhanced. Now let us shift over from this far- into-the-future speculation to a nearer term speculation near and dear to our 21st century hearts, cryonic revival. It will probably be many years after the achievement of organic replacement immortality that our descendants will figure out how to do cryonic revival, and for that we may need all the state-of-the art nanotechnology of that future time. Those revival technologists will presumably have satisfactory answers to the questions we now ponder about the nature and true seat of personal identity. None of us wants our frozen selves to be revived as either empty-headed clones or robotic simulations, and I have enough faith in the future to believe that our would-be revivers-saviours will be fully cognizant of our wishes in that respect. Don't beam me up, Scotty, unless I'm absolutely sure that it's really me! Ron Havelock, CI member Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=21746