X-Message-Number: 27578 Date: Sat, 4 Feb 2006 21:28:10 -0500 Subject: For Robert From: <> My old friend Robert joins me in the discussion. I hope retirement is treating you well. >> Not that it has much practical importance at this time, but I take mild issue with RBR's statement that criteria of identity depend on logic and philosophy, not technology. << Of course, I simplify for the sake of people who aren't as familiar with these ideas as we are. It would be pointless to discuss details that are three levels beyond where most people are at. To you, however, I would say this: that while the definition of identity is a priori determined by logical and philosophic considerations, the questions of (a) what properties are relevant to subjective experience, and (b) what processes (specifically related to methods of preservation) are compatible with the ongoing obtainment of those properties. These are scientific questions, not logical or philosophical ones. And until they are answered, a definitive answer to such questions as, 'How much damage can our brains sustain before "revival" becomes, from our subjective, first- person perspective, identical to death?' will remain out of our grasp. In a sense, the definition of identity doesn't tell us what we can survive (that's a question for science), only what we absolutely cannot; for example, I don't survive if my brain is ground up and used to grow potatoes, while an accidental copy is created on another galaxy by a machine that randomly builds 3x2x1 meter objects with atomic precision. The accidental clone is not me. The distinction between the copy and me is what identity is all about. Identity gives us hard answers to all-important questions such as, 'Is that cup of coffee I see before me the cup of coffee I set down 5 minutes ago?' (important because if it is, my colleagues will agree to let me drink it; otherwise, all bets are off). >> As one example, RBR, if I remember correctly, ties his definition of identity to continuity of time and space (apparently ruling out quanta of time and space). << No, I don't require those properties. I use smooth space-time because the definition would be three times more complex if I didn't. And honestly, I think just two or three people understand my existing definition, among the hundreds who read Cryonet every day. >> They constantly confuse dimensions, coordinates, degrees of freedom, and parameters. << Aye, sloppiness abounds everywhere. Richard B. R. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=27578