Saturday, October 24, 2009
There is an explanatory gap between the subjective sensations in our minds and the objective nature of the physical reality but is that gap merely physical in nature or is there an actual metaphysical difference between them? In other words, is that a difference only in degree or in their very nature?
The fact that there is even a problem here seem to elude most people, it's hard to realize what it is and even harder to explain it. There is this default position that consciousness is, in principle, knowable and explainable in the framework of modern neurology and that there are no reasons to think otherwise.
So are there good reasons to think otherwise? I'll try to show them by using robots as an example.
Building the robot.
For this to work we need to establish an assumption. Let's presume that everything that makes up a human being can (in principle only) be constructed in a robot. I think this is the default position and it basically means that, if we're just chemistry, then there's no reason why the same chemical principles can't apply in a robot. Where there's a group of nerve cells transmitting electrical signals, there can be an electrical wire. Where there's muscle there can be a small engine. Where there is skin there can be an organic compound that behaves like skin.
This is obviously an over-simplification but the actual materials and techniques are not important for the purpose of this article. The only important thing to presume is that each part we choose for our robot will maintain the same behavior as the human counterpart.
Building the feeling of pain.
Now let's say that we build this robot in a way that will enable it to experience pain.
Beneath the surface of a robot's skin there are pressure sensors. When pressure increases beyond a certain threshold, where further pressure could be threatening, the sensor (nerve) emits an electrical signal through a set of wires (nervous system) that are connected to a central processing unit (the brain). When the signal reaches that CPU, a procedure is fired so that the head and eyes track the source location of the signal to get more information, at the same time another procedure is fired that emits a laud noise and another procedure is fired to attempt to withdraw the arm away from the source of the pressure.
So by hammering the finger of that poor robot, the robot would turn it's head to you, scream and then withdraw the arm away from you.
Let's presume that all of this was so perfectly simulated that you could not distinguish between the behavior of that robot and a human being's behavior. The result is that we have just succeeded in simulating pain!
Or have we?
The truth is that we've only succeeded in simulating the behavior of pain but not the feeling of pain and it's important to distinguish both. Is that robot experiencing the feeling of pain? Not at all. Would it be immoral to torture that robot only because it behaves as if it was feeling pain? Now what if we threaten the robot to hammer his finger again, could we program it to feel fear? Again, it doesn't seem possible. Sure, he could have the logical pathways to recognize potential danger and avoid it by running away from it. It could effectively SEEM as if it was feeling fear but it still wouldn't be experiencing the feeling of fear.
In a way, those sensations can be said not to exist at all in physical reality and they don't seem to logically follow from it. Would it be impossible for life to have developed into creatures like that robot? Creatures that, through the course of evolution by natural selection, have acquired the necessary programming to survive and replicate, while behaving as we behave, yet being devoid of subjective sensations? Is there a difference between us and that description of those robots if we're just biological machinery anyway? There's no difference in behavior but you'll probably recognize that the robot of our little thought experiment is not a person since it doesn't feel anything.
So what would it take for the robot to feel? There just doesn't seem to be a way since all we can construct are behaviors and not feelings. The problem is that what we feel is in the subjective realm of our mind and not on an objective physical reality, it's surely correlated with it but it's still unexplained by it and more importantly, it's seemingly unexplainable by it alone, which is what I mean by there being a difference in the nature of those things and that would entail that the assumption we started out with is probably wrong.
As a final note, this is one of those subjects that defy our language. It's so difficult to find the words to express this problem, but if the article was unclear, maybe its main concepts can be better understood by reading this other article: The metaphysics of color, which distinguishes the subjectiveness of our feelings from the objective phenomena that it relates to, in the world, using color as an example.
By Smig at 10/24/2009