Brad Delong is Puzzled by Richard Campbell
Would you still be conscious if your neurons were replaced by (functionally identical) silicon chips?
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We can similarly wonder whether Block’s "Chinese Nation" (a functional analogue where individual humans communicating via walkie-talkies play the role of neurons) is really conscious. There’s not any physical fact we’re ignorant of here. So if there’s a substantial fact we remain ignorant of, it must concern a matter over and above the physical facts. That is, it must be a matter of non-physical fact.
I don’t know whether Richard Chappell believes that Block’s Chinese Nation is really conscious–I am not sure whether I believe that Block’s Chinese Nation is really conscious–but it’s not because I am uncertain about any matter of non-physical fact. It is because I am uncertain of the meaning and definition of "really conscious."
“Really conscious” doesn’t bother me much. Lets ask this question: When the “Chinese Nation1” finally completes the signals necessary to represent the processing of the color red, is there any being which experiences the color red.
Said another way, is it “like anything” to be a Chinese Nation. It is like something to be person. We are pretty clear on that. I am guessing that its like something to be dog. I don’t know if its like anything to be a worm. I am pretty sure its not like anything to be a rock.
Campbell is asking “is it like anything to be a collection of people with Walkie-Talkies”
That being said, however, I think Campbell is wrong on the physicalist question. We don’t yet have all the answers. There are more experiments we can do.
The most straight forward experiment would be for me to have the part of my brain responsible for processing the color red replaced by chips. I might then be able to tell whether my qualia had disappeared.
Now, immediate problems pop out – I don’t deny. For one thing unless we’ve gotten something wrong I ought not be able to tell anyone that my qualia has disappeared. From the point of view of the outside world all of the processing in my brain is happening the same way and so I should respond in the same way.
However, if it really has disappeared but I can’t express that then I can’t know that. But, if I can’t know that then what does it mean to say its gone. All very interesting questions that lead to only one conclusion – we need to start cutting into some brains because I am dying to see what if, anything actually happens.
More seriously though, even the attempt to answer some of these practical question can yield useful insights. Suppose for example there is a particular mechanisms within the neurons that is hard to model and seems to act really weird.
We say, ok close is good enough NSF grants and we do the implants without that mechanism. Suddenly our patient tells us that his sense of red is gone. He knows that the picture is red, he can even tell you how red. He just isn’t experiencing red. Well, know we know a lot more about qualia than we did before and we know a lot more about the physical processes that lead to consciousness.
It may be that when someone conducts a Chinese Nation thought experiment that involves replicating this particular complex mechanism that the outcome of a “conscious nation” won’t seem counterintuitive at all. “Well of course if you could get 100 billion humans to all do that, the result will be conscious” we will all say.
Now maybe that won’t happen and we’ll completely reduce the process of cognition down to its most basic parts and be left with no more intuition about consciousness. Maybe. But, I don’t know how we can be sure that will happen from where we are standing right now.
(1) The string of references is long but this has nothing to do with the nation of China. Start here