Non-computability.

According to Roger Penrose, humans can perform non-computable feats, such as dealing with Gödel questions. He uses this as a foundation to claim that the human mind cannot be expressed in terms of classical processes, and as such must be party to the only other (known) game in town: Quantum Mechanics.

Now, I haven't had the patience to sit through all of his arguments yet, though I slowly make progress. My understanding is that a large part of his stance is that an algorithm cannot usefully deal with a Gödel question, or equivalently, with the halting problem, while a human can.

My objection to this is that such problems always demand a certain quality of response when asked of UTMs: failing to respond forever is not acceptable as correct, nor is providing any response other than one that yields a truth when taken in combination with the question. This much is fine, however, when it is time for the human to answer, he is permitted the liberty of rejecting the question on the grounds that it is inherently unanswerable.

Obviously I am interested in artificial intelligence, and also find his assertion to be simply a self-serving one with a contrived philosophical backdrop for foundation. If anyone knows of, or can think of, a more sophisticated argument than the one above (or expose my flaws in my assessment of it) I would like to hear it.

Apologies for bringing up a largely philosophical question, my only excuse is that I cannot trust any other board with the question.

>>70,71
There is a bit of a frustration of terms. Above and beyond basic intelligence (in the sense of problem-solving), limited consciousness (in the sense of alertness) and awareness (in the sense of having access to information to make use of in intelligent behavior), the terms are heavily contested in semantics and the associated concepts are often argued to evaporate under scrutiny. Few philosophers will stop with just these concepts, but this is roughly where broad agreement stops.

Personally I'm happy to consider all of the above to be in the domain of machines without worrying about it. Only when we go into the more robust concepts of (say) consciousness do we have to start asking hard questions. The problem is really that we often don't know what we are talking about, and hunting for that is the larger part of the problem. One good thing about Penrose's argument is that he at least tries to take something concrete and well-defined and tries to argue that a TM can't produce it. The problem, of course, is the double-standard applied (which is analogous to saying that other animals cannot be intelligent no matter what they might do or what features they might have simply because they are not human. It's a valid concept of intelligence, but generally useless... it's not 'analytic'.)