PHIL/AI : A Humongous Lookup Table

John K Clark (
Sat, 15 Feb 1997 09:45:13 -0800 (PST)


On Thu, 13 Feb 1997 Hal Finney <> Wrote:

>suppose [...] It turns out that ESP and telepathy is possible with
>the right training. In time you learn to directly perceive the
>innards of another person's mind. You see what he sees, follow his
>thoughts, feel what it is like to be him. Now, if you're going to
>start suggesting that you don't know if this is real

No, I am not suggesting that. The emotion I feel when I use my ESP to probe
your mind is absolutely real, no doubt about it. The question is, is it the
same emotion that you experience? It's far from obvious that it is, after all,
the exact same input can make you very happy and me very sad.

>that you can't be sure that you are really feeling what he feels

But how can I be sure? I don't have ESP but I often see people and think that
if I were in their position I would be very happy, but I'm not the one in
that situation, and they are and to my surprise they tell me they're

There is a problem when you say what would I be like if I were you, or what
would this be like if it were that, because then it wouldn't be "this"
anymore. The problem is not too bad if the two things are similar, it makes
some sense to ask "what would this apple be like if it were blue", it would
make less sense to ask "what would this apple be like if it were a blue

Asking what somebody else's subjective experience would be like if it were
yours, is like asking what would this post be like if it were a blue giraffe.

>then this starts to sound like solipsism.

This is a separate issue, but I could not function if I really thought that
solipsism was true, so I take it as an axiom that it is not. You claim that
a proof that solipsism is not true can be found, I think any such proof would
be flawed.

>You would be directly perceiving his mind

Even with ESP there would have to be a translating mechanism from your mind
to mine, and something could get lost in the translation.

>If the person whose mind I am reading agrees with my statements
>about what he seems to be feeling,

We both agree that a stop light and a tomato are the same color, but how can
I know if the color you subjectively experience is the same one I do?

>if other people reading his mind perceive the same things I do,

I have no way of knowing if other people perceive the same thing that I do,
the only thing I know about is the sound other people make with their mouth.

>then I have grounds for believing them to be real.

I agree, you certainly do have good grounds for believing that other
conscious minds are real, I believe it too, we just don't have proof. I am
far less certain that the subjective experience those other minds have is
very similar to mine, but I'll never know for sure.

>It's not clear what it means for John Clark to be Hal Finney, and
>how that differs from Hal Finney being Hal Finney.

I don't care what it's like when John Clark pretends to be Hal Finney,
what's it like to be the real Hal Finney?

>Suppose that while John Clark is being Hal Finney, he feels exactly
>the same as Hal Finney being Hal Finney. Then, when the mind reading
>is over, he goes back to feeling like John Clark, but he still has
>his memories of what it felt like to be Hal Finney

But then Hal's memories would be interpreted by John Clark not by Hal Finney.

John K Clark

Version: 2.6.i