I cannot begin to grasp what it must have been this experience for this poor man, but I can very vaguely imagine. A recent book and film used the metaphor of a diving bell. You are inside your body as if you are inside a diving bell. It's alright when you can control your diving bell. You swim around and interact with all other beings in diving bells you encounter. Suddenly something happens and you loose control of the diving bell. Your life as such is not threatened; but you can't communicate any more, you can't interact. You are trapped inside.
I think, therefore I am. Cogito ergo sum in Latin.
Descartes' picture of the situation seems to fit perfectly with what we can picture of this Belgian man's situation. In fact he says it himself. "I knew what I could do and what I was capable of but other people had a rather pathetic image of me. I had to learn to be patient and now finally we are on an equal footing" BBC quotes him as saying. His body could fool anyone around him, presenting him to be in deep coma, but it could not fool him.
Descartes' hypothesis is now taken as fact by most people in the western world especially in its far-reaching implications. What I "am", my mind, spirit or soul, inhabits and uses this body of mine, but this not necessarily a permanent state of affairs. In fact it is perfectly reasonable to hypothesise a mind outside the body, even in absence of the body. The "mechanics" of this need not bother us. The "mind" might be a soul in the old-fashion kind of way, or it might be a software-type of entity, running on a specialized processing platform, the brain. The thing is that for many people out-of-body experiences, either through some kind of paranormal activity (as in "The Eyes of Laura Mars"), or through simulations (like in the "Matrix" trilogy) are perfectly conceivable.
It is ironic that this idea, of the total independence of mind and body, which could be seen as liberating –and for Descartes it certainly was, since it offered him the foundation he needed to free his intellect of the deceit of the senses and reach truth– has many disturbing side effects. Unfortunately these side effects are not easy to combat. I shall only give two examples here.
Example 1: Treating the mind as an entity alongside the body reduces the body to a thing that is of lesser importance to the mind (or soul). If my own body is a thing, then the same of course applies to your body, or to everybody's body (no pun intended); they all are things. Therefore, if I am very convinced of the truth and nobility of my ideas, I might decide to become a suicide bomber, confident in my belief that bodies are disposable but souls are not.
Example 2: Picturing the brain as a sophisticated processing platform on which the mind "runs" like a software, allows one to conceive mental illness and distress as a malfunction of hardware, treatable via sophisticated medication that interacts with this very hardware. In fact, treating the hardware of the brain (for example via inhibitors of neurotransmitters) is more important than treating the software –a nice twist in the story since we don't really have medication that could work with the software of the mind; thankfully we don't need it!
You see what I mean? These are traps, and you will fall into them, whether you are a religious person, honestly concerned about the road our world has taken, or a knowledgeable neuroscientist, genuinely trying to alleviate suffering and mental distress.
Because, of course, there is nothing whatsoever that could show us that the mind–body dichotomy hypothesis is valid, syllogistically unavoidable, or even useful. It's a nice metaphor, a fairy tale, a partial model of the world. But it's not true.
It took no less a philosopher of Heidegger's stature and no less than hundreds of very difficult and condensed pages, written in the first half of the 20th century, to show human beings as being-in-the-world, attuned and open to other beings, comported to Being as such. Heidegger wanted to show that the mind-body hypothesis is an unnecessary artefact of its time, and warned against the increasing tendency to treat human beings as mere objects of this world, objects of exploitation, manipulation, observation or experimentation.
But then, who reads Heidegger today?