Another great concern of Descartes was that some things were material; and others, such as the human mind and God, were spiritual. This was his ‘ontological dualism’. It was the one fraction of his thought that later philosophers weren’t impressed by. Yet, to me, it is obvious and unproblematic that the brain is material and resides in the skull, and that the mind which consists of feelings, thoughts, dreams, nostalgias, behaviours, desires, cultures, civilizations, tastes in reading, tastes in carpets, ironies and responsibilities, is not material. It resides in the brain, develops from it in the course of evolution, is damaged if the brain is damaged; but is itself a great ethereal bubble of non-materiality. The idea that all these constituents of the mind or self will one day be explained as electrical impulses in nerve cells is the product of a mind with an impoverished inner life who lives in a university laboratory.
It seems that this ontological dualism wasn’t something already accepted as obvious at the time! It seems it was something revolutionary that Descartes hoped would leave the spiritual world of Mind and God for the Church to continue to act in, while the Church would leave scientists to do empirical investigation of the Material and mechanistic world (see here).
I am even more astonished that Cartesian Dualism set the agenda for ‘The Mind-Body Problem’ in Philosophy of Mind for centuries to come, see here. It astonishes me to read that many later philosophers disagreed with Descartes’ dualism, and even thought it ‘mythical’! Did they seriously believe that everything is material, and that the self is just the brain! Were these only the grim materialists of modern times but earlier philosophers too? It shows what an impoverished experience of mind is present in the minds and lives of philosophers.
Some moderns even think that Artificial Intelligence (which I imagine is capable of logicking and mathematicking) is like the human mind! It goes along with the banal examples from human life and speech that they exhibit their mechanical intelligences on (see here).
The law of the land assumes the self to be independent of physics and biology in much of its activity, and to be responsible for much of what it does.
But Descartes, being generally materialistic and mechanistic, did need to find a place where brain and mind interacted. He picked on the pineal gland, which hangs off the bottom of the brain, as the location where motivations from the mind crossed into the brain to initiate muscular movements, and where pain sensations in the brain crossed into the mind.
Later philosophers didn’t think much of Descartes’ pineal gland theory, so they thought up other theories for the interaction of Matter and Mind, such as Materialism, Idealism, Behaviourism, Occasionalism, Epiphenomenalism, Pre-Established Harmony, Double AspectTheory, etc. Look these up; they are amazing.
It seems that Descartes believed that our minds carry on after our brains have died. Modern scientists don’t, which is another reason they believe the brain is the mind.
For me, daring to use a philosophical term, it has always been a gigantic ‘Category Mistake’ of Thought to think that logicking with words can solve the conundrum of the relationship between bodily brain and the mind! And why on earth ‘solve’ it? One has to have a simplistic understanding of the misty universe of ‘mind’ to think one can ‘solve’ it.
Why is there even a need to postulate exactly where they interact – just leave it at the everyday experience that there is thinking mind and a material brain and the exact nature of their interaction is unfathomable. To pick on the pineal gland or anything else is the sort of thing a rationalistic mind would do to satisfy its need for an answer to something unfathomable. Philosophers use logic to try to solve what are imponderables to logic, but these imponderables remain imponderables by the very nature of imponderables and of logic (as I’ve already said here). Descartes himself In a letter late in his life, see here, wrote that ‘the union of mind and body is best understood by not thinking about it, and that it is just one of those mysteries that has to be accepted without being comprehended’. Yes,exactly! but moderns think that neuro-science will one day solve it.