Dualism and the Nature of the Mind
Introduction
You've never seen your brain, but you're certain you have one. Of course, even though you've never seen your brain it could easily be seen by a neuro- surgeon if necessary. But what about your mind? You've never seen your mind either, but you're just as certain that you have one. However, here there is a difference. Not even a neurosurgeon could see your mind. In fact it can't be seen, tasted, smelled, touched, heard, weighed, chemically tested, x-rayed, and so on. Yet we don't need scientific or any other confirmation of the existence of our minds and its contents. Mostly we are absolutely certain about our thoughts, desires, beliefs, pains, fears, dreams, etc.It seems then that none of our normal methods for establishing the existence of something can apply to the existence of the mind. Yet we are in no doubt about its existence. What exactly is the mind? What is its nature? More specifically, Is the mind fundamentally non-physical and hence forever beyond description and explanation by physical science? The theory of the mind called Dualism, still probably fairly widespread outside philosophy, answers yes. The theory is called dualism because it states that a person is composed of two fundamentally different types of thing - a physical brain and body on the one hand, and a non-physical mind on the other. Is dualism true? I don't think so, and will outline some of the main difficulties faced by the theory.
In order to explore the nature of the mind it is better to ask about the contents of the mind, for the mind may not be a thing at all. In other words, let's ask about the nature of the mind's contents - those states, processes and events such as a felt toothache, a belief in life on Mars, a nightmare, a fear of snakes, a desire for an ice-cream, etc. We can call these states, events and processes “mental”, and ask the question: are these mental states, events and processes non-physical and thus of a fundamentally different order from the physical states and events which occur in the brain? Dualists say yes to this question too. But are they right?
Why be a dualist?
What are the arguments in favour of dualism?- The examination of the contents of our minds is called introspection. Introspection reveals our thoughts, beliefs, hopes, fears, memories, etc. But it does not reveal anything physical such as electrochemical activity in the brain. Dualists conclude that therefore what is revealed by introspection is not anything physical.
However, it could be replied that when I observe a table I don't see any atoms. Yet for all that a table is a collection of atoms. - The existence of parapsychological phenomena points to the fact that the mind is not physical and is therefore beyond the reach of physical science. Parapsychol-ogical phenomena include telepathy, clairvoyance, precognition and telekinesis. According to dualistst these phenomena have no physical explanation, so we are forced to conclude that the mind is not a physical system.
However, a reply to this is that these phenomena (assuming their existence in the first place) may have a physical explanation. The fact that it has not yet been discovered doesn't mean that one can't be found.
Problems for dualism
- Causal interaction: mental events cause physical events. Wanting and intending to go swimming causes me to go swimming, and feeling itchy causes me to scratch. Also, physical events cause mental events. Thus, stepping on a nail causes a painful sensation. So mental and physical events causally interact. But how is this possible if, as dualism asserts, mental events are non-physical? If A causes B then there must be some sort of contact between A and B. But how can there be any sort of contact between physical and non-physical events?
- Other minds: if the mind and its contents are non-physical somethings located inside our skulls, then could I know whether or not you have a mind? I know that I have one because I'm directly aware of its contents. But if dualism is right then I couldn't possibly know anything about your mind - I have no reason to believe that you have one. So dualism leads to scepticism about other minds.
- Continuity of nature: we observe a smooth development of individual human beings from the union of sperm and egg --> zygote --> embryo -->fetus --> infant -->adult. At what point might a non-physical mind first pop into existence?
Do sperms and eggs have minds? Does the mind just suddenly come into existence at birth? Or at some other point? Yet the development we observe doesn't seem like that. Individual organs such as brains don't just pop into existence but develop smoothly and gradually. The dualist theory of the mind doesn't seem to account at all well for this continuity in the development of human beings.
Moreover, a similar point applies to humans in comparison with other animals. At this level there also seems to be a continuity in the hierarchy of complexity from single-celled organisms through to mammals and humans. At what point in this hierarchy does mind first come into existence? Do amoebas have minds? What about worms? Cockroaches? Sharks? Frogs? Snakes? Sparrows?Wombats? Dogs? Dolphins? Chimpanzees?
- Emptiness of dualism: the 20th century has seen enormous progress in neuroscience. We have learnt a lot about neuroanatomy, neurochemistry, neuropsychology and neurophysiology. Thus, for example, we know a lot about the neural basis of memory, language, learning, recognition of faces and about the basis of diseases such as epilepsy and Parkinson's disease. Furthermore a lot is known about the neural basis of the effects on consciousness of substances like alcohol, narcotics, caffeine, anaesthetics and pharmaceutical drugs. The brain and the mind seem very closely related, contrary to what we would expect if, as dualism states, the mind is non-physical and fundamentally separate from the brain. As well as this we know virtually nothing about this supposed non-physical mind, nothing about its structure, function, operations, laws governing its behaviour or its constitution. It's a complete mystery. Of course it may exist despite being mysterious, though note that if dualism is true then the workings of the mind must be forever mysterious. We are left wondering: if we are making interesting discoveries about the connections between the brain and our mental life, then why should we care about the possible existence of a mysterious non-physical mind?
Some questions
- Are there any other reasons for believing in the existence of a non-physical mind? How convincing are these ?
- Mental states such as pains have certain qualities such as being throbbing, stabbing, stinging, burning, etc. Whether or not there is such a thing as a non-physical mind, isn't it true that these qualities of our mental states are somehow non-physical?