Let me make clear that when I reference “dualism” I essentially mean a view which accepts that the “mind” is made up of a different substance (be that physical or nonphysical) than the body. When I spoke about the nonphysical soul being an idea originating with Descartes, I mean it: though the soul was a concept before Descartes (a concept I find useful and use myself), the idea of this soul being something other than the physical stuff of the world was, as far as I can tell, new to him. You mentioned the mind-body problem in ancient Greece, but for most of Greek history, the soul was comprised mostly of pneuma, a physical, though very light and “rarified” substance which belonged mostly to the air. Pneuma was still “stuff” and a part of the rest of the universe. This idea of a parallel “spiritual realm” to the physical one is (I think) a Descartesian invention.

Now, that aside, it seems like we have drifted into the related realm of the problem of consciousness. There’s an easy and a hard problem of consciousness. The easy one is something like “why is there consciousness?” Not easy in the sense that you can answer it over tea, but consciousness is necessary to solve certain forms of complex or adaptive problems and one would assume would have an evolutionary advantage. How it arose, okay who knows, but it’s conceivable that an answer could be found. The really hard one, and the one you’ve brought up, is “why does consciousness [b]feel[/b] like anything at all?” You can postulate some system of thought and adaptation, but why this should feel like something and why it should be so personal is… well, difficult.

Now, to my mind, this is a separate question from whether the consciousness is something “of this world” or not. As I suggested in this post, I don’t see any reason to think it isn’t part of this world. I certainly can’t make anything approaching an airtight argument, but I can gesture toward hardware and software and say, “see, you can come up with logical, adaptive systems without the need for nonphysical properties.” Yes, that doesn’t address the hard problem. I’m not going to dare attempt to address it because it seems to me pretty near insoluble. As you mentioned, the problem of other minds is here too: I can’t demonstrate you have a consciousness, I just assume that you do. I maintain my adaptive advantage by not slipping into solipsism. And plus, I think solipsism is silly.

You asked me questions like measuring love and so forth, and I think we could, given the right equipment, measure the chemicals and hormones that produce the experience of love. We cannot, as you brought up, measure the [b]experience[/b]. We cannot, at least not presently, “get inside” anyone else’s mind so that we experience the same things. But this says nothing one way or the other about mind-body dualism. I may very well not be able to experience what you experience because I have a different physical brain which is undergoing different chemical processes and processing that information. It doesn’t tell me why it is that I feel ownership over me, so that I am “me” and you are not. But we can assume the obvious reality of conscious subjectivity without driving a wedge between body and mind, and brain and mind.

Your response covered a lot of ground and I won’t address everything, but I will address the main points. In particular I want to focus on the mind-body problem and less on the question of free will. I probably did not phrase my response to the other post as best as I could. What prompted me to respond was your very strong conviction that there is only a physical body; an idea which I think does not justify such confidence. I threw in the issue of free will because for the most part I do think any extreme physicalist position does imply complete determinism. As you pointed out however, these are two separate issues. I want to focus on the first. Also, I won’t touch on the religious aspects you mentioned, as the mind-body problem is not a specifically religious problem, and for me at least it never was. In essence the mind-body problem is the problem of consciousness.

At the outset I should say that I am not a dualist or a monist. Perhaps it’s a sign of indecisiveness but I don’t see a reason to “pick a side” in this and many other philosophical debates, at least not at this stage of my intellectual inquiries. What I do seek however is to understand the problems. I have no answers, only questions. Another thing I want emphasize is that my inquiries here are epistemological, not metaphysical or ontological. That is, I’m not concerned here with the broader problem of whether there is a nonmaterial mind and if so how or whether it interacts with the body, only with the question of whether we have any reason to think that such a mind exists or does not exist. As I said I’m not a dualist, but I find the dualist case stronger than the monist case. Hopefully, I’ll be able here to articulate why.

These thoughts have been echoing around inside my skull for some time, with all the emotion and logic and passion that goes on inside a human skull.

This is the mind-body problem summed up. You have emotions, passions, feelings, desires, memories, likes, dislikes, ideas – all of which you perceive and experience as real nonphysical phenomena. You also have a skull, inside which is the brain, which you know is a complex physical organ, a part of your physical body.

You mentioned Descartes. While I don’t think one can say that a line between the physical and the “spiritual” didn’t exist before Descartes drew it (the mind-body problem existed already in ancient Greece and in all the major religions), it is true that he is the person who emphasized the problem more than anyone else before him and thus defined the mind-body problem in the modern philosophical form which concerns us to this day (incidentally, he did not claim that mind and body are two separate realms that never interact, rather that they are two separate realms that do interact, and that each one could influence the other). For that, and for other important achievements in philosophy, in mathematics, and in science, I think he deserves more credit than you give him. That said, I agree that his attempts at solving the problem of mind-body interaction were not only unsuccessful but downright bizarre. His glandular solution is not even a solution as all it does is redefine the question of how the soul interacts with the body, to how it interacts with a specific part of the body, the pineal gland.

You say you don’t see any reason to postulate mind-body dualism, but in the sentence I quoted above, you provide an example of just why the problem is so complicated. What Descartes and others after him pointed out was that we are aware of two things:
1) The world and everything in it (and that of course includes the human body and the human brain) are physical, and can be measured and described in physical categories – mass, volume, temperature, physical-chemical composition, etc.
2) We experience mental phenomena that cannot be measured and quantified in such a way.

This is a problem which requires a solution. As I said earlier, I’ll focus only on this most basic epistemological foundation of the mind-body problem and not get into broader metaphysical or ontological issues such as the nature, so to speak, of nonphysical entities, the interaction and causal relations between mind and body and the question of free will and determinism.

The physical world, its mechanisms and processes are in the public domain of knowledge. That is to say, all people are equal with respect to the knowledge they can attain about the physical world. Consciousness, however, is in the private domain and is completely inaccessible to anyone but the person who experiences it. This also brings up the notorious problem of other minds, but that’s a separate issue.

Right now I’m typing this response to you. You can study my fingers, their anatomy and the process by which I move them up and down and across the keyboard. You can study my motor and sensory systems whereby my brain interacts with my fingers and you can study all the physical-chemical processes going on in my brain. Despite the fact that it’s my brain, I have no advantage over others in studying it. My brain as a physical entity can be studied by all and whatever I know about the processes going on in my brain – you can know. But only I know why I’m replying to you and what I’m going to type, and only I can experience the feeling of my fingers hitting the keys and the challenge of expressing myself clearly. By studying my brain all you study are chemical processes, it doesn’t explain why I feel the keys against my fingers and why I know I’m going to end this sentence with a period. My brain doesn’t feel anything; I feel. I want to type and my brain sends signals to my fingers and they start typing. What gave my brain the signal that I want to type?

You compared the human body to a computer. That comparison is sound but it serves the dualist case just as well, if not better, than the physicalist case. Leibniz preceded your comparison by about three centuries with a comparison of his own. The only difference between your computer and Leibniz’s windmill is that your computer is a much more complicated machine than an 18th century windmill, but essentially they’re the same. As physical entities, their mechanisms do pretty much parallel biological processes, which are merely the most complicated form of physical and chemical processes. You can see how your computer works like you can see how your brain works. In the computer and in your body, all that’s going on are physical and chemical processes. I question whether the difference between a person and a computer is merely a matter of degree, as you suggest, or whether it’s a qualitative difference.

The computer is really the perfect tool for understanding the complete chasm between the physical and the mental. All physical processes can be measured and quantified, which means they can be translated into the language of a computer. Mental phenomena cannot be measured or quantified and not even the most super-duper of supercomputers can give any sort of output regarding them.

The distance between Tel Aviv and Eilat is greater than the distance between Tel Aviv and Jerusalem. This a physical statement so the computer can tell you exactly, down to the millimeter or down to whatever decimal place you want, by just how much the distance between Tel Aviv and Eilat is greater than the distance between Tel Aviv and Jerusalem.

Jacob’s love for Rachel was greater than his love for Leah. By how much was Jacob’s love for Rachel greater than his love for Leah? You can’t ask a computer this question and it won’t be able to give you an answer. Love cannot be measured or assigned a numerical value.

Now, you might say that you disagree with the question. That you maintain that love, like all conscious phenomena, is an illusion and that it is nothing but chemical processes going on in the brain, and that those can be measured. But chemical processes are just that – why ascribe love to them? How do we deduce love from electrical pulses and chemical reactions? Why assume any consciousness here, even an illusory consciousness? I want to point out that the issue is not whether Jacob loves Rachel more than Leah out of his own free will; the issue is that he feels he loves her more than Leah. He has the experience of loving Rachel more than Leah.

Let’s take an even more arresting example. Do I think that 2 + 2 is 4? You’ll probably say: Well, anyone who is remotely sane and minimally intelligent thinks that, and as you don’t seem like an escapee from an insane asylum I believe that you do in fact think that. Now, that’s a fair assumption, and I think it’s safe to say we all believe that others around us would agree with that statement. But, by what conceivable means could you possibly tell that that’s what I think? Is it that we don’t have machines sophisticated enough to detect the content of my thought, or is it that it’s impossible? But if thoughts are physical products, why should it be impossible? Even assuming you could somehow know for certain the content of my thoughts in the way you know the content of a water molecule, how could you understand my experience of thinking? Everyone is equal with regards to what they can know about the physical world. That means you should be able to know my experience and feelings as well as I do.

A final example: colors are physical products which are assigned numerical values and which can be detected by machines. Blue for instance has a wavelength of about 440-490 nm (at least according to Wikipedia). It’s entirely possible that we both will agree that the sky is blue, but how can you know that what I perceive and experience as blue is not what you perceive and experience as red? Consulting a machine won’t help.

There’s a lot more that can be said about the problematic fact that we experience consciousness which cannot be described in physical properties, but I think this suffices. Does this mean that a nonphysical mind exists? Not necessarily. But it does mean that dualism is not as untenable as you imply, and that physicalism is a very problematic supposition of its own.

With regards to free will, I agree with you and I think even the most hardened determinist would have to agree with you, that we experience having free will and act accordingly. As such we are all responsible for what we do of our own volition, regardless of whether that volition is free or not.

That emoticon was just for you.