Can We Trust Experience?
As a materialist (physicalist) one of the most difficult things to explain the the actual phenomenology of experiencing things. This is called the hard problem of consciousness because it seems to be an insurmountable gap in explanation. The materialist believes this will be explained one day, while other philosophical positions believe they know enough about what is happening to say with confidence that we will never be able to explain how these qualia come about.
Consider pain: we can easily understand the sensors in the skin that are triggered by various material situations. Raise the temperature of the skin, and we can see how this causes heat sensors to become activated. We understand that nerves then carry this information to the brain. We understand how reflex actions are cause that jerk a hand away from a flame. We also can reasonably understand how once pain is sensed, the person may use this to purposefully move the hand consciously. All of this is either understood, or at least conceivable. What we can’t explain is why we experience pain as a sensation. The term qualia is used to describe these units of qualitative experience. Pain actually feels like something and that something feels completely unrelated to the movement of any molecules.
Consider the taste of apple pie: we can easily understand that there are taste and smell sensors that are activated when certain molecules are present. We can understand how a combination of these are triggered by the combination of aromatic molecules that come from an apple pie. We can understand how nerves carry that signal to the brain, where they can be associated and the brain can recognize that it is apple pie instead of, say, pumpkin pie. We can understand how that might then cause us to make a decision to have a piece of the pie, and even to start salivating in preparation for that. That process is understood or at least conceivable. What we don’t understand is why we experience that as the flavor of apple pie and that that experience is pleasurable.
Qualitative Difference
The non-materialist claims that the experience of pain and the experience of apple pie are qualitatively different from the actions of things in the world. Some times the things in the world are described as “quantitative” in the sense that they have a place in space, a dimension or special size, and a place in time as well, while the experience of apple pie has no particular place that it can be located at. The experience of apply pie appears to be entirely separate from the world.
There is a long tradition of thinking that this phenomenology is separate from space. Descartes placed all of consciousness in an entirely different realm, the res cogitans, from the material world, res extensa. Western religious tradition theorizes that there is a spirit which is separate from the body, and the spirit does the experiencing, while the body moves about the world.
Where this “qualia” comes from is the hard problem of consciousness. Let me just clarify at this point that I do not claim to have solved this problem. I don’t know why we experience apple pie as a particular qualitative experience. Nobody understand why we experience the way we do. The question though is one of whether one believes that a material interaction is capable of producing this phenomenology. The materialist says is possible, while other say it is impossible. As you can imagine, this is the crux of some very strong debates, and feelings of disbelief about others.
I am aware that the experience of the smell of apple pie, or the feeling of pain, appears to be entirely separate from material interactions. That is the way it seems to us. Yet there is a very important fact about this claim: these experiences are experienced by a running mind and are interpreted by that mind as being the way they are.
Self Understanding
How much can a mind really understand about itself? If I write a program in Java, it is impossible for the Java program to know how it is being run. Without special features from outside the Java language that provides a representation of the underlying hardware, it is impossible for the program written in Java to know what kind of processor it is running on. Is it a 5 volt chip, or a 100 volt mainframe? I believe this analogy explains an important principle about the relationship between the brain and the mind: if the brain is the underlying hardware, and the mind is some kind of process running on the brain, there are bound to be things about the brain that the mind simply will not know or sense in any way. This is simply saying that the mind might not know how the mind works, and nobody should be surprised as this remains a great mystery.
I am NOT suggesting that the mind is just like a Java program. The mind runs on entirely different principles. The analogy is just to be clear that what a mind understands things about the world is quite different than what the mind understanding how it works itself.
Is the Experience Mistaken?
We still can ask the question: do we have any reason to believe that the mind is mistaken about experience? I believe we have very good reason to doubt that experience is an accurate representation of what is going on.
As evidence for this I turn to various “optical illusions”. They are optical because they are images, however it is really the mind that is being fooled. These illusions appear to us in a way that we can, though examination, understand is not true.
The first is a pattern that appears to be spinning wheels, but this is actually a completely static image. We know that the wheels are not turning, but we nevertheless have the experience that they are turning. It is worth reflecting on the fact that even if we know the wheels are not turning, we have a very real experience of them turning. We might describe the spinning as an epiphenomenon — that is an illusion that appears different than reality — but notice that even as an epiphenomenon the experience is very real. We really do experience spinning that is not there.
Here is a second pattern just to experience it a different way.
The anti-materialist says: materialism can not explain this spinning or motion that I experience, and that experience of motion is real, while the atoms are clearly not moving, therefor there must be a non-material source of that motion. This experience is used as evidence that there is more to the universe than just materialism.
What we learn from this is that our real experience -- our qualia -- might not be accurate about the relationship between that experience and reality. This makes it clear that we can not trust those experiential phenomena as being an accurate representation of the world.
Illusion of Separation
What the materialist proposes is that when we experience pain as being something separate from material world, that separation from the world is an illusion. The mind is not able to understand the phenomena is caused by material interactions, and so the experience seems to be unconnected and separate from the world. That separation might be an illusion.
This is not to say that the experience of pain or apple pie is not real. The experience of pain and apple pie are very real experiences that the mind actually experiences, but the feeling that these experiences are qualitatively separate from the world is an illusion.
Nobody knows why pain is painful, but the materialist believes it is possible that painfulness comes from material interactions (forms and processes). Just because we experience these as qualitatively separate from material processes does not mean that in reality these are separate. We know this could be an illusion, because we know that optical illusions give experiences which do not represent reality.
Where does the spinning in the optical illusions come from? That experience is real, yet it is something obviously based on a false perception of the world. Why can it not be the case that the feeling that pain is separate from the physical processes is an aspect of experience that is simply based on a false perception of the situation?
Clearly we are far from establishing how qualia actually come from material processes, but we simply can’t say that this is impossible. The feeling that it is impossible could easily be an illusion.