Gelernter spoke of his project to emulate these workings of the mind in a computer program. He said the spectrum’s “top edge,” where rationality predominates, is easiest to model; it gets harder lower down, where we become less like calculating machines and more emotive. And Gelernter said – categorically – that no artificial system would ever be able to feel like a human feels.
Gelernter replied at great length. He said that some man-made systems already approach that degree of complexity (actually, I doubt this), but nobody imagines they’re conscious. He quoted Paul Ziff that a computer can do nothing that’s not a performance – a simulation of mind functioning, not the real thing.
I found none of this persuasive. Someone later asked me what’s the antithesis of “computationalism.” I said “magicalism.” Because Gelernter seemed to posit something magical that creates mind, above and beyond mechanistic neural processing.
Talking with Gelernter afterward, he offered a somewhat better argument – that to get a mind from neurons, you need, well, neurons. That their specific characteristics, with all their chemistry, are indispensable, and their effects could not be reproduced in a system made, say, of plastic. He analogized neurons to the steel girders holding up the building – thanks to steel’s particular characteristics – and girders made of something else, like potato chips, wouldn’t do.
But I still wasn’t persuaded. Gelernter had said, again, that computer programs can only simulate human mind phenomena; for example, a program that “learns” is simulating learning but not actually learning as a human does. I think that’s incorrect – and exemplifies Gelernter’s error. What does “learning” mean? Incorporating new information to change the response to new situations – becoming smarter from experience. Computer programs now do exactly this.
Neuronal functioning is very special and sophisticated, and would be very hard to truly reproduce in a system not made from actual neurons. But not impossible, because it’s not magical. I still see no reason, in principle, why an artificial system could not someday achieve the kind of complex information processing that human brains do, which gives rise to consciousness, a sense of self, and feelings.**
Those who’ve said something is impossible have almost always proven wrong. And Arthur C. Clarke said any sufficiently advanced technology is indistinguishable from magic.
* In 1993 he survived an attack by the Unabomber, whose brother, David Kaczynski, has been to my house (we had an interesting discussion about spirituality) – my three degrees of separation to Gelernter.
** See my famous article in The Humanist magazine: The Human Future: Upgrade or Replacement.