Does a copy know?

John K Clark (
Sun, 21 Sep 1997 13:39:00 -0700 (PDT)


On Sat, 20 Sep 1997 Geoff Smith <> Wrote:

>[What makes us different?] I would say location. (I think JK would

Me and my exact copy and standing an equal distance from the center of
a perfectly symmetrical room. A mad scientist presses the button on a magic
machine that he claims will instantaneously exchange my brain with that of my
exact copy. He presses the button but I notice absolutely no difference, he
says "that's because the senses of the ordinal and the copy were sending the
same signals to whatever brain happened to be in it's head". You are also
present armed with CAT scans and MRI's and EEG's and high speed cameras and
lots of other good stuff, but you can find no change when he presses the
button either. Our loony friend says "that's because the two brains were
identical, but really there was a huge change, I mean, after all, I exchanged
the brains". I maintain that absolutely nothing is happening and if there is
any difference between this man and a charlatan the difference is too small
to be measured.

In 1690 the philosopher and co-inventor (with Newton) of The Calculus,
Gottfried Leibniz, wrote about something he called " The Identity Of
Indiscernibles ". He said that things that you can measure are what's
important, and if there is no way to find a difference between two things
then they are identical, and switching the position of the objects does not
change the physical state of the system. This idea has turned out to be of
paramount importance in the scientific method, exchange forces in modern
physics and The Pauli Exclusion Principle in particular could not be derived
or understood without it.

If objectively there is no difference and subjectively there is no difference
then there is no difference, nothing is happening when the button is pressed
and identity and consciousness can not be a function of position.

On Sun, 21 Sep 1997 Kennita Watson <> Wrote:

>The two may be the same at the instant of copying, but as soon as
>they are in different locations, they begin to have different inputs,
>so their thoughts begin to diverge.

I agree with that entirely, if they get different inputs they will start to
diverge. I think that means survival is not a binary all or nothing matter.
The 3 year old John Clark may not be completely dead but he's not as alive as
the John Clark of today.

John K Clark

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