The whole concept of creating intelligence and consciousness is mainly interesting because it makes one think about what being intelligent and conscious exactly means. In my opinion, the investigation into the subject up to the late nineteenth century was largely phenomological since there was no means of testing or putting ideas into practice. Also theories were not self consistent, since the very basis of them could not be proven or even be made plausible. This was caused by a lack of insight into the way our world is structured. And although I believe that we are only at the very beginning of discovering what 'the world is all about'. New theories like quantum mechanics and chaos theory, combined with the invention of computers has given the first proper tools to study the fundamentals. That we are only at the very start of understanding can easily be seen by the fact that many of the people that we see as 'great thinkers' differ so much in their opinion about the matters discussed here and their consequences. This is even enhanced by the fact that so many different fields of research are combined in the study of artificial intelligence: from mathematics to linguistics, from physics to sociology.
It is fascinating to see the power of utilisation of simple mathematics to describe for example the flocking of birds or the pre-biotic soup. Although many people will think that this 'demystification' of life is a negative thing, I for one believe the opposite; it will open (and has opened) up many new possibilities that can satisfy man's hunger for understanding. And for the people who long for the mysticism in their life: I don't think they need to worry. Proving the 'impossibility' of their feelings is as ridiculous as proving them to be right; that is the very nature of beliefs.
One cannot deny the power of the work done on cellular automata. The results are simply too striking. It has opened up completely new ways of studying all sorts of different fields like (molecular) biology. The point I would like to make is that the distinction between theories that describe intelligence, consciousness or more simple natural phenomena and reality as it is, is a false one. It might be impossible to prove that birds actually flock according to simple mathematical rules; but the mere fact that these rules do describe the flocking is enough to draw conclusions. The same can be said for artificial intelligent systems. One cannot simply ignore artificial intelligence if it functions in the same way as 'natural intelligence'. And the same conclusion must be drawn for possible artificial consciousness. It can best be shown in a thought experiment. Imagine meeting an extraterrestial being. I doubt that anyone would not consider it a conscious being (except for the galactic version of a racist maybe) if one could relate to it in a similar manner as to a fellow human being. But it is not very likely that its intelligence and consciousness are constructed in the exact biological way as humans. In fact it only shows that intelligence and consciousness are not products of the biological structure but more the capabilities of that structure. The same holds in the case of an artificially created intelligent and conscious being. The only difference is that we know it is biologically different from us. I think this is the heart of the research into AI. In a sense we are as much 'artificially' created as (future) robots.
Actually, the thought experiment described above makes another thing clear. So far intelligence and consciousness have been studied from an extremely human-centric point of view. We define consciousness as being human consciousness. It is far more logical to see humans as possessing a form of consciousness shaped by the way they process information and interact with the environment. I think consciousness at the deepest level is much more the ability to develop self-recognition of reasoning. In this sense, artificial intelligence and consciousness created by humans will necessarily be human-like. The things mentioned by Toulmin to be part of consciousness (culture, history etc.) and which are implicitely used by Brooks in the construction of COG, I believe are not so much essential but much more contributions to the cognitive process. Culture and social structures do not define consciousness, they merely shape it.
As with respect to the involvement of quantum-mechanics, the situation is very unclear. The philosopical aspects of quantum-theory are not well understood at this point in time. However, I think one can doubt any findings on the field of quantum physics will influence the view towards artificial intelligence and consciousness. Indeed, as Penrose wrote, any insights on the quantum level are physically objective and independent from consciousness. But I would like to draw another conclusion than his. If this independency is true, than quantum physics is nothing more than the building blocks of the structures that define the world. A computer or a robot is also built of out of molecules, atoms, quarks and thus quantum phenomena also play a role in such bodies. Quantum structure plays a similar role as the biological structure (although on a more fundamental level). It is vital for the construction of any system, but it precise working is not the essence of all the capabilities of those systems, in particular intelligence and consciousness.
Dennett's work to me is remarkably self-consistent. Already in this respect it is ahead from any of the other theories or criticisms. He has taken away from all the older theories parts that only rely on beliefs and intuition. Whether this is a valid procedure future research will tell. But at least it gives a basis to study intelligence and consciousness in a solid way. One can claim intuition is an important part of human consciousness and is not based on algorithms, but it is far more interesting to assume it is algorithmic and try to create consciousness. His philosophical arguments about determinism and freedom are controversial, but seem right to me. They indeed show the misconception that many people have on the subject. It is as Jean-Paul Sartre said: 'We are doomed to be free'.
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