[net.philosophy] Continuity and Personal Identity

mangoe@umcp-cs.UUCP (Charley Wingate) (08/30/85)

In article <621@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes:

>The question is, in what sense is this the resurrection of the "same" person,
>instead of just a "copy"?  To make the question more pointed, suppose two
>such "copies" are made simultaneously; are both the same person?

>This question is not of purely religious relevence; we will have the
>technology to make such copies soon (within 30 to 100 years, I would guess;
>but the time scale is not important to the philosophical argument).

I've replied to this problem in private mail, but since there seems to be
general net interest, I'll repeat the series of thought-experiments I
presented there.  Let us start by considering how a person when he is
young is the same person as he is when he is old.  For the sake of this
argument, let's assume that there is no supernatural component to a person;
since this makes things the most difficult.  Now, it's clear that the
physical body in and of itself does not constitute physical identity, since
large portions of the body can be lost, and yet it is the same person.  So
the mind plays some part in identity (and may indeed be the only component).

Now consider a person of whom an atom-by-atom copy is made.  Through which
does the chain of identity pass?  There are four possibilities; either it
passes through one or the other, or both, or neither.  I think it's
reasonable to claim that identity continues with the original.  So the
question becomes where the identity of the copy comes from.

To elucidate this, consider the third experiment.  It this case, a copy is
made *which destroys the original*; this is essentially matter transmission.
Now the question is, is there an identity chain through the transmission?
If you choose to deny identity to the copy in #2, then it seems to me that
in this case the person dies in the transmission, and a new person appears
at the other end.  If you choose to have continuity through the
transmission, then it seems to me that in #2, one must say that identity
passes through the copy as well as the original in #3.

As a result of these, it appears to me that the options for transmitting
identity are very broad indeed.

Charley Wingate

franka@mmintl.UUCP (Frank Adams) (09/06/85)

In article <1442@umcp-cs.UUCP> mangoe@umcp-cs.UUCP (Charley Wingate) writes:
>In article <621@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes:
>
>>The question is, in what sense is this the resurrection of the "same" person,
>>instead of just a "copy"?  To make the question more pointed, suppose two
>>such "copies" are made simultaneously; are both the same person?
>
>I've replied to this problem in private mail,

(which I did not receive)

>but since there seems to be
>general net interest, I'll repeat the series of thought-experiments I
>presented there.  Let us start by considering how a person when he is
>young is the same person as he is when he is old.  For the sake of this
>argument, let's assume that there is no supernatural component to a person;
>since this makes things the most difficult.  Now, it's clear that the
>physical body in and of itself does not constitute physical identity, since
>large portions of the body can be lost, and yet it is the same person.  So
>the mind plays some part in identity (and may indeed be the only component).

This does not necessarily follow.  (Although I do agree with the conclusion.)
There are those who will argue that it is the *continuity* of existence which
matters.  When large portions of the body are lost, the lost portions die,
while the remainder is still a living organism; thus it is reasonable to
ascribe the identity to that portion.

Perhaps a better example is childbirth.  There is continuity from the
pregnant woman to both the mother after birth and to the infant.  Why do
we identify her with one and not the other?  I won't go so far as to claim
that no continuity-related argument is possible, but I think commonality of
thought and memory provides a more convincing explanation.

>Now consider a person of whom an atom-by-atom copy is made.  Through which
>does the chain of identity pass?  There are four possibilities; either it
>passes through one or the other, or both, or neither.  I think it's
>reasonable to claim that identity continues with the original.  So the
>question becomes where the identity of the copy comes from.
>
>To elucidate this, consider the third experiment.  It this case, a copy is
>made *which destroys the original*; this is essentially matter transmission.
>Now the question is, is there an identity chain through the transmission?
>If you choose to deny identity to the copy in #2, then it seems to me that
>in this case the person dies in the transmission, and a new person appears
>at the other end.  If you choose to have continuity through the
>transmission, then it seems to me that in #2, one must say that identity
>passes through the copy as well as the original in #3.

It is quite consistent to maintain that in case #3, there is no identity
between the original and the copy.

Let me deal with an alternative case.  There is a recent novel by Kim
Stanley Robinson, titled _Icehenge_.  In this he posits the development
of techniques whereby lifespans are extended to centuries.  However, he
assumes that memories of more than about a century or so are lost.  Leave
aside the question of whether it would work that way, and assume it does.
Is a person who has lost all memories of an earlier time still the same
person?  One may assume that there will still be behavior patterns and
attitudes in common, but the commonality is potentially quite vague.
On a theory of continuity, of course, there is no such problem.


So, you ask, having presented arguments for both sides, where do I stand
on the issue?  The answer is very simple -- there is no such thing as
identity.  Or more precisely, identity is a convenient linguistic tool
for dealing with the universe in ordinary cases, but it breaks down under
closer examination.  It is not a property of the universe, but of the way
we think about the universe.

That being the case, the original question (whether a resurrected or
reconstituted person would be the "same" as the original), becomes purely
a question of what definition we wish to use for identity; i.e., a purely
semantic argument.

mangoe@umcp-cs.UUCP (Charley Wingate) (09/10/85)

In article <634@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes:

>>  Let us start by considering how a person when he is
>>young is the same person as he is when he is old.  For the sake of this
>>argument, let's assume that there is no supernatural component to a person;
>>since this makes things the most difficult.  Now, it's clear that the
>>physical body in and of itself does not constitute physical identity, since
>>large portions of the body can be lost, and yet it is the same person.  So
>>the mind plays some part in identity (and may indeed be the only component).

>This does not necessarily follow.  (Although I do agree with the conclusion.)
>There are those who will argue that it is the *continuity* of existence which
>matters.  When large portions of the body are lost, the lost portions die,
>while the remainder is still a living organism; thus it is reasonable to
>ascribe the identity to that portion.

Certainly.  But the question that must then be asked is WHICH portion is
essential?  Frank conveniently answers this:

>Perhaps a better example is childbirth.  There is continuity from the
>pregnant woman to both the mother after birth and to the infant.  Why do
>we identify her with one and not the other?  I won't go so far as to claim
>that no continuity-related argument is possible, but I think commonality of
>thought and memory provides a more convincing explanation.

>>Now consider a person of whom an atom-by-atom copy is made.  Through which
>>does the chain of identity pass?  There are four possibilities; either it
>>passes through one or the other, or both, or neither.  I think it's
>>reasonable to claim that identity continues with the original.  So the
>>question becomes where the identity of the copy comes from.

>>To elucidate this, consider the third experiment.  It this case, a copy is
>>made *which destroys the original*; this is essentially matter transmission.
>>Now the question is, is there an identity chain through the transmission?
>>If you choose to deny identity to the copy in #2, then it seems to me that
>>in this case the person dies in the transmission, and a new person appears
>>at the other end.  If you choose to have continuity through the
>>transmission, then it seems to me that in #2, one must say that identity
>>passes through the copy as well as the original in #3.

>It is quite consistent to maintain that in case #3, there is no identity
>between the original and the copy.

If by that you mean that "there is no identity between the copy and the
original *after the copy is made*," then I fully agree.

>Let me deal with an alternative case.  There is a recent novel by Kim
>Stanley Robinson, titled _Icehenge_.  In this he posits the development
>of techniques whereby lifespans are extended to centuries.  However, he
>assumes that memories of more than about a century or so are lost.  Leave
>aside the question of whether it would work that way, and assume it does.
>Is a person who has lost all memories of an earlier time still the same
>person?  One may assume that there will still be behavior patterns and
>attitudes in common, but the commonality is potentially quite vague.
>On a theory of continuity, of course, there is no such problem.

>So, you ask, having presented arguments for both sides, where do I stand
>on the issue?  The answer is very simple -- there is no such thing as
>identity.  Or more precisely, identity is a convenient linguistic tool
>for dealing with the universe in ordinary cases, but it breaks down under
>closer examination.  It is not a property of the universe, but of the way
>we think about the universe.

>That being the case, the original question (whether a resurrected or
>reconstituted person would be the "same" as the original), becomes purely
>a question of what definition we wish to use for identity; i.e., a purely
>semantic argument.

I think perhaps it is more fruitful to examine what transformations preserve
identity, and to what degree.  Has an amnesiac truly lost his identity?
What about brain damage?  I would also note that with our rather limited
understanding of consciousness (and the unconscious, for that matter), most
of these questions must remain grounds for speculation only rather than for
assertion of fact.

Charley Wingate   umcp-cs!mangoe