X-Message-Number: 25263 Date: Fri, 10 Dec 2004 18:10:49 -0800 (PST) From: Scott Badger <> Subject: Re: Identity I wrote: >Let s try something else. How about the >classic thought experiment where the natural brain s >neurons are replaced, one at a time, by artificial >neurons which are precise duplicates until the normal >brain was completely replaced by an artificial brain? >Where is the line at which the QE is destroyed and how >do you justify the existence of that line? Richard: Assuming the scenario is possible, then the QE is NOT destroyed. Remember the criterion for survival: you survive from time T0 to T1 if at all points T in [T0, T1], your physical system is Capable of experiencing qualia. This implies that replacing the neurons of your brain one at a time with (as you say) precise functional duplicates would not result in your personal destruction. Scott: So we finally agree on something. The human mind CAN BE sustained on a non-biological substrate with the original QE. Richard: Contrast this with near instantaneous replacement of all your neurons (e.g. mass disassembling and then recreation): there is a time when your physical system lacks the ability to experience qualia---when you exist as 'information' (which is another way of saying, you don't exist at all, since nothing can exist as information). Since the physical system that was your brain ceased to have a QE (i.e. became incapable of experiencing qualia), you did not survive; and assembling from your remains another QE, even in the likeness of your own, is not a continuation of your inner subjective life. Scott: So if the instantaneous replacement of all your neurons with artificial duplicates destroys the QE, just how quickly can I replace them if I do so one at a time (assuming there was no limitation to how quickly I could replace them)? Just a fraction of a second short of instantaneous? Also, your last post made it clear that you re pretty critical of the idea of exceeding human limitations or enhancing human capabilities (with the notable exception of extending your own maximum life span), but what if I wanted a bigger, more powerful brain? Assume my brain has successfully been replaced with let s say, silicon-based, artificial neurons and my QE survived. Assume also that these silicon neurons can be easily manufactured and I can add as many of them to my existing system as I wish. The size of my skull would restrict how many I could add to my system internally, but a silicon version of a corpus callosum it seems to me could allow my mind to expand its reach to an external silicon-based system. Or perhaps a physical cord wouldn t be necessary at all, and a wireless connection could be used. I don t think there s anything so far about this scenario that s disallowed by your theory, right? Now let s say the external system I choose to build and expand into is a replica of the brain system inside of my skull so that my internal system gets connected to an identical external system. Being identical to my internal system, the external system also has the structures necessary to experience qualia and begins doing so as soon as I expand into it. So the two systems have become one system, and qualia are happening to both of my QE s, both of which would be having the same internal subjective experience. So now I have a redundant brain system and the accidental or intentional loss of either QE structures would not result in the destruction of the original QE since the overall physical system remains capable of experiencing qualia and continuity would be maintained. Have I broken any of your theory s rules yet? If not, haven t I just uploaded without losing my original QE? Scott: The closest thing to what Richard is describing that I ve seen is Michael Gazzaniga s Interpreter theory. Richard: If these quotes are representative, and I have interpreted them correctly, then Michael is in gross error. Scott: I see. Given Dr. Gazzaniga s considerable experience and reputation in this field, and given the empirical evidence he cites to support his theory, you ll forgive me for not readily accepting your sweeping dismissal of his ideas since I m unaware of your experience and reputation in this field. Richard: Evolution does not produce a little man in the brain, whose purpose is to passively observe the macroscopic operation of the system, but effect no change. Scott: I assume you base this on an earlier assertion you made which I believe to be false. I ve always heard the idea that evolution is so efficient that its products always have survival value or purpose is a myth. Natural selection involves a lot of trial and error, a lot of dead ends. Am I wrong? Best regards, Scott Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=25263