Nature also teaches me, through these sensations of pain, hunger, thirst and so on, that I (a thinking thing) am not merely in my body as a sailor is in a ship. Rather, I am closely joined to it—intermingled with it, so to speak—so that it and I form a unit. If this were not so, I wouldn’t feel pain when the body was hurt but would perceive the damage in an intellectual way, like a sailor seeing that his ship needs repairs. And when the body needed food or drink I would intellectually understand this fact instead of (as I do) having confused sensations of hunger and thirst. These sensations are confused mental events that arise from the union—the intermingling, as it were—of the mind with the body. Descartes, Meditation 6
Descartes is, of course, the arch-dualist. Mind and body are different substances with entirely different natures and can exist independently. Human beings, on the other hand, are not just their minds (even though the mind is the ego who’s existence we know first, and best). The things that teach us that we form a kind of unit — pain, hunger, thirst, etc. — are perceptions of the body which differ from how experience the rest of the world.
I was thinking about this because I’ve been feeling like crap for months now. Clearly there is a strong physical element, but equally so, there’s a strong mental component. They go back and forth in a complex dynamic but it’s not always clear which is which or even if they are fully separable. If I dry heave, it could be pure anxiety, a stomach virus, or a side effect of medication (perhaps for anxiety).
The most striking (for me) example in my personal history was the interaction between my inner ear issues and social anxiety. When I was a teen-ager, I developed an inner ear disorder that ranged from subtle to extremely overt (i.e., spinning for three days at a shot). But effect of the subtle variant was that in noisy environment with a fair bit of motion, my ability to distinguish my movement and other objects movement was diminished. (Think of being on a smooth and slow moving train when it just starts up and you’ve been distracted.) This can make you feel very uneasy and off balance and…anxious.
This inflected my experience of social gatherings…dances, parties, etc. When this got really going I would feel unsettled and uncomfortable and usually seek a quiet berth (kitchen, outside, or…not there). Part of this was undoubtably due to this inner ear phenomenon, but I had no idea that it even existed. So I interpreted this mostly physiological reaction as being a dislike of parties or part of my social anxiety. Which didn’t help the anxiety at all. On the contrary.
We know that many physical illness tend to have certain mental co-morbidities. Being sick sucks, so depression isn’t uncommon.
Our Cartesian unity…the fact that we are a big muddle of a complex system…makes life difficult. Our parts don’t swap easily.