Stanford University, 1996
Consciousness is a natural phenomenon. No scientific theory of the universe can be said complete if it does not explain consciousness.
The simplest explanation of why the physical sciences cannot yet explain consciousness is that they are not complete. An element is missing in the fundamental, irreducible, constituents of the world. Science could not explain electricity if it did not assume a fundamental property of matter, i.e. the electrical charge. Just like electricity cannot be reduced to gravitation, because it is fundamentally different, consciousness cannot be reduced to material quantities, because it is not a material phenomenon (as we all can feel).
No matter how detailed an account is of the neural processes that accompany an emotion or a thought, that account cannot explain how the emotion or thought is built. No theory of the brain can explain why and how consciousness happens if it assumes that consciousness is somehow created by some neural entity which is completely different in structure, function and behavior from our feelings.
Only if consciousness originates from a fundamental property of matter (from a property that is present in all matter starting from the most fundamental constituents), can we study why and how, under special circumstances, that property enables a particular configuration of matter (e.g., the human brain) to exhibit "consciousness".
Ex nihilo nihil fit. Conductivity seems to appear by magic in some configurations of matter (e.g., metallic objects), but there is no magic: just a fundamental property of matter, the electrical charge, which is present in every single particle of this universe, a property which is often useless but that under the proper circumstances yields the phenomenon known as conductivity.
Particles are not conductors by themselves, just like they are not conscious by themselves, and most things made of particles (such as wood or plastic) are not conductors and probably have no consciousness, but each single particle in the universe has an electrical charge. And I claim that each single particle in the universe has a property C, the property that allows our brain to be conscious.
I am not claiming that each single particle is conscious or that each single piece of matter in the universe is conscious. I am claiming that each single particle has this property C which, under the special circumstances of our brain configuration (and maybe other brain configurations as well and maybe even things with no brain) yields consciousness. Any paradigm that tries to manufacture consciousness out of something else is doomed to failure.
Why have we not yet detected that property in labs? Because we have not been looking for it, and because our Physics may not be adequate to detect that property C.
First of all, we know that cognition is a property of living organisms that comes in (continuous) degrees. Animals are cognitive systems too: we can only argue that their cognitive faculties are somehow "lower" than ours. Cognitive faculties can be detected even in non-living things: a piece of paper bent many times will "remember" being bent (will stay bent) for a long time, and will eventually lose that "memory" (will return to a flat position) over time, in a fashion similar to how we remember and forget. Memory and learning can be said to be ubiquitous in nature, as long as we assume that they come in degrees. Cognition is therefore a general property of matter, not limited to human beings or animals, but simply distributed in different degrees.
Furthermore, Quantum Mechanics is built upon probabilities, and that choice forces a specific interpretation of the universe. The interpretation of quantum phenomena would be slightly different if Quantum Mechanics was based on Fuzzy Logic: probabilities deal with populations, whereas Fuzzy Logic deals with individuals; probabilities entail uncertainty, whereas Fuzzy Logic entails ambiguity. In a fuzzy universe a particle's position would be known at all times, except that such a position would be ambiguous (a particle would be simultaneously "here" to some degree and "there" to some other degree). Fuzzy Logic may actually provide a model of the universe that is more plausible (i.e., not random but deterministic) or at least more in line with our daily experience that in nature things are less clearly defined than in a mathematical representation of them.
My theory is both dualistic and materialistic. Like dualists, I admit that consciousness is separate from the physical properties of matter as we know them; at the same time, like materialists, I believe that consciousness arises from a physical property (that we have not discovered yet). In a sense it is not a "physical" property, but it is still a property of all matter.