X-Message-Number: 26697 Date: Tue, 26 Jul 2005 09:14:58 -0400 From: Thomas Donaldson <> Subject: more on identity and equivalence To Mike again! Sorry, Mike, but your abstract definition once more fails to produce a clear notion of identity AS DISTINCT FROM what you call equivalence. How do we work out that every member of set A also belongs to set B, and presumably vice versa? As a guess, something is a member of set A if it has characteristics x,y,z, and a member of B is it has those same characteristics. Infinite lists of characteristics won't work here, either.... not just for practical reasons, but for the simple reason that even the possession of ONE characteristic raises the same problems about identity. There is a lesson here that bears a lot on discussions of whether we survive or not --- survive our suspension, for instance. No one so far has insisted that we retain ALL PREVIOUS characteristics upon our revival. Nor has anyone claimed that we survive if the opposite happens. In my previous discussion of this subject I gave a short discussion of what I was at age 10. I would suggest that we take this notion as a definition of survival of cryonic suspension, too: we may not retain all our memories, but we retain some, particularly important ones to us. If our abilities differ from those we had before our suspension, they will have come as developments of abilities we had before our suspension. As for our memories and abilities, their survival will resemble the normal survival of both: upon our revival and recovery, we'll still be able to ride a bike if we knew how to do so before, and ditto for playing a piano. Yes, in a sense we're continuous from the time when we were 10. Specifically because our repair may require a loss of physical continuity, I will say that survival by my definition does not require physical continuity, but does require a continuity of memories and abilities as I describe it above. Again, this definition also contains the requirement that duplicates which satisfy the same definition for identity do not exist. Note that such duplicates might have different memories and abilities from you after your revival, but will have the same relation given above to yourself before suspension. In that sense I require that you be unique. I will add, as a reason for this clause in my definition, that failure to be unique will change almost everything about you by changing your relations with others and any possessions you had before suspension. Finally, THIS IS A DEFINITION. It is not an axiom or rule of any kind. Anyone who wishes to propose additions, changes, or alternatives is welcome to do so. Best wishes and long long life for all, Thomas Donaldson Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=26697