One of the major topics that we discussed with Tom Weidig last night was the origin of consciousness - the ability to be aware of oneself; to distinguish oneself from the environment; to act as a subject; to feel the information encoded in the perceptions and in own decisions.
If there were no consciousness, you might think that the behavior of the world would be indistinguishable from the behavior of a world that does not exist - simply because there would be no one who feels that the world does exist. Whether or not subjects and objects have consciousness sounds as a philosophical question whose solution goes beyond the scope of science, but it is hard to convince yourself that the question is completely vacuous.
Everyone who believes solipsism is convinced that he or she is the only entity that exhibits consciousness, and all other people and objects are mechanical entities that can't realize their existence. That might be a fine attitude. However, the apparent physical similarity between your humble correspondent and other humans in the world suggests that one should not be using entirely different theories for me and entirely different theories for the rest of the mankind.
This simple argument leads me to believe that other people have consciousness, too. Are we talking about the people only? Do small babies have consciousness? What about people who are just sleeping? What about other mammals and fish? And what about plants, bacteria, or individual cells in your body? Do computers feel something if they are calculating or playing a game against you? Is a Hydrogen atom able to realize its own energy level? On the opposite side, is a city or nation able to realize its own existence much like a single human brain? Does our planet, often painted as a single organism, have a similar kind of consciousnes as individuals?
I think that the right conclusion that follows from the interpretation of quantum mechanics based on consistent histories and decoherence is that every physical system is able to realize the value of any projector that can be inserted into consistent histories - products of projectors that are used to predict the probabilities of different outcomes of a physical experiment.
The humans are able to realize what they are thinking about, what they remember, and what they see. Chimps can do the same thing. A Hydrogen atom "feels" that it was hit by a photon. The New York City knows that it was hit by hijacked airplanes.
It is rather clear that the previous sentences are untestable. If we study consciousness at a deeper and more detailed level, we inevitably approach the physiological mechanisms in the human brain that make consciousness interesting. Whenever we try to define consciousness more accurately, we end up with some well-known physical processes. People are able to speak, remember, and process information. They can design strategies. They are able to respond to stimuli. Clearly, all these things may be studied by the standard scientific method. In fact, they are studied by science.
The Hydrogen atom cannot remember what was going on. It cannot design intelligent strategies. Even if you accept that the atom has consciousness, there is a gap between the atom and a human being.
When you think about a word, you don't have to say it. On the other hand, the only reason why you don't say it is that a switch in between the brain and your mouth is turned off, whatever is the reason. If you accept that the physical essence of this switch is trivial, then you find out that the nontrivial mechanisms that allow you to think about a word are more or less identical to the mechanisms that allow you to say the word.
A similar conclusion applies to other kinds of ideas that may be running through your brain.
When you see a color, you have a particular feeling. There is something about red that distinguishes it from the green color. It's not just the frequency or the fact that most of us are able to translate the frequency of the electromagnetic light to the letters R-E-D. It's not just the fact that the bulls are driven up the wall. There is also a feeling that you can't describe with words. Imagine that someone else has exactly the same feelings when he sees green as your feelings when you see red, and vice versa. Of course, he will learn to use the same word for the same wavelength of light - but his feelings will be different. Is it possible? Can you experimentally decide whether it's the case? Does the question make any sense?
Again, science can look what's going on microscopically. When a red photon arrives to your retina, it excites a particular kind of color receptors. Human beings tend to have the same receptors for the three colors we are able to distinguish. If you study these perceptions at the level of human eyes, everyone has the same feeling if you believe that the feelings are uniquely associated with the processes that occur on your retina.
Of course, the signals from the retina are transmitted to your brain and the details of the communication system may differ from one person to another. And we evaluate these signals differently. Nevertheless, it is fair to say that this translation of the visual perceptions to signals in the brain is straightforward.
While you might want to say that the real "consciousness" does not occur on the retina but deeply inside the brain, it is associated with the ability of the brain to manipulate with the information from the eyes and other sources. Pragmatically speaking, you can pretend that consciousness is a feature of only those objects that are able to evaluate or remember some information.
Consciousness has a political dimension, too. We usually find murders bad because it hurts. If there is a dull object that does not feel anything, it is morally acceptable to kill it. Do the embryos feel something? What about small children one month after they're born? It is not hard to demonstrate that the babies who are younger than one year don't really exhibit the kind of higher mental processes that I connected with consciousness above. Does it mean that they can be freely killed? Not quite because there are many other reasons why we consider such acts immoral.
Can these moral laws be derived scientifically? Is the presence of complicated brain processes equivalent to the rule that the entity should not be killed? Obviously, things are more complicated in the real world. When you ask whether animals have human rights, the answer often is that only the cute animals have human rights. Those who are loved and protected by someone. In the real world, the strength of human rights clearly depends not only on the strength of consciousness as defined by the intensity and depth of mental processes, but also on many other things.
Are cloned people conscious? I think that the answer to this question is clearly Yes. They are physically indistinguishable from the people who were born as a result of the old-fashioned methods. Will computers with an artificial intelligence be conscious? I would say that the answer to this question is also affirmative. If you emulate a neural network by replacing every neural cell by a small component such as a transistor and if you make it work just like the human brain, then I believe it is fair to say that the machine is isomorphic to the human brain, and we should admit that it has the same degree of "consciousness".
Consciousness is a great thing but once again, it is not the ultimate factor that decides about the real world. If the robots ever start a revolution, trying to kill all the humans, most of us will probably have to fight against these robots regardless of the question whether they're conscious or not.
If you read the text above several times, you may join me in believing that every question about consciousness that can be defined operationally can also be studied by scientific methods. But you may still feel that there exists an additional level of concepts - such as consciousness and moral values - that could perhaps have objective answers that however can't be found scientifically because no scientific concept is quite equivalent to the kind of "consciousness" that we have normally in mind.
But maybe you're just fooling yourself and there exists nothing beyond science that would deserve a serious discussion. The whole realm of complicated manipulations with the information and all the difficult causal relations between processes are accessible by the scientific method; the particular conscious "codes" associated with different states of matter are probably outside the realm of science. But maybe we're not missing much. It may be the case that it is more fun to live with consciousness rather than to analyze it rationally.
And that's the memo.