There is a distinction drawn in theories about the human mind between ‘monist’ and ‘dualist’ understandings of how it works. Dualists, like Descartes, see the mind as essentially separate from the body. Monists believe that “the mind is what the brain does,” and that there is no distinction between the two.
The position of the two views in society is an odd one, as an excellent Paul Bloom lecture discusses. We can readily understand situations that presume dualism: the continued life of the soul after death, the idea that the mind of one person could be transferred into another person or animal, etc.
Hundreds of years before the birth of Christ, Homer described the fate of the companions of Odysseus who were transformed by a witch into pigs. Actually, that’s not quite right. She didn’t turn them into pigs. She did something worse. She stuck them in the bodies of pigs. They had the head and voice and bristles and body of swine but their minds remained unchanged as before, so they were penned there weeping. And we are invited to imagine the fate of again finding ourselves in the bodies of other creatures and, if you can imagine this, this is because you are imagining what you are as separate from the body that you reside in.
Clearly, we are able to imagine minds that would remain essentially unchanged, even when altered into a radically different physical form.
At the same time at dualism seems to make intuitive sense to people, all the physical evidence we have is on the side of a monist view, in which ‘mind’ arises from the physical properties of body:
Somebody who hold a–held a dualist view that said that what we do and what we decide and what we think and what we want are all have nothing to do with the physical world, would be embarrassed by the fact that the brain seems to correspond in intricate and elaborate ways to our mental life.
Somebody with a severe and profound loss of mental faculties–the deficit will be shown correspondingly in her brain. Studies using imaging techniques like CAT scans, PET, and fMRI, illustrate that different parts of the brain are active during different parts of mental life. For instance, the difference between seeing words, hearing words, reading words and generating words can correspond to different aspects of what part of your brain is active. To some extent, if we put you in an fMRI scanner and observed what you’re doing in real time, by looking at the activity patterns in your brain we can tell whether you are thinking about music or thinking about sex. To some extent we can tell whether you’re solving a moral dilemma versus something else. And this is no surprise if what we are is the workings of our physical brains, but it is extremely difficult to explain if one is a dualist.
The lecture includes many other examples showing why monism and the world as we observe it seem to mesh.
To me, the importance of this seems to go beyond settling scientific and/or metaphysical questions. It certainly seems plausible that beings that intuitively perceive themselves as essentially independent from physical reality will develop high-level theories about the world that take that into account, in areas as diverse as their religious, political, and moral views. By the same token, if one view really is far more defensible than the other, on the basis of observations and experiments we perform, that quite possibly has moral and political implications. It is all quite interesting, in any case, and I recommend that people consider watching the lecture series. The videos, transcripts, and slides are all available for free online.