The Mind-Body Problem N ormal day-to-day activities seem at first very ordinary - PowerPoint Presentation

The Mind-Body Problem

N ormal day-to-day activities seem at first very ordinary: You are reading a book and eating an apple. You don’t need to read aloud—you read in your mind. Take a bite of your apple and taste that sweet apple taste. You feel thirsty and that feeling makes you get up and go to the kitchen to get a glass of water.

On closer examination, these ordinary activities are not so ordinary: What exactly are thoughts? How in the world can your thoughts cause you to do things ? After all, to make a physical object move , you need another physical object. How can a thought, which is non-physical, move the physical? More precisely: how can a 3lb oatmeal-like organ composed of billion of cells think?

These and other such questions are what we know as the mind-body problem .   The reason why we call this a problem is that it is very difficult to understand why and how physical matter has thoughts, feelings, desires, in other words, a mental life. Existence of consciousness/mental life is mysterious.

To appreciate the depth of the mind-body problem, let’s break down the problem into 4 parts: Consciousness. I ntentionality. Subjectivity. Causation.

1. Consciousness You have been conscious most of your life. You have all kinds of sensory experiences . Your experiences have a quality to them . For example, you can hear my explanation of what durian tastes like, but unless and until you taste it, you don’t have the quality of experience. Why has the physical body such capacities?

2. Intentionality You have many beliefs, thoughts, feelings, hopes, fears, in other words, many mental states . Mental states have aboutness . You believe that you are a college student. Your beliefs are psychological attitudes that have a mental content: they are about college , a city, and a certain relation between these things. Also, you believe that it is false that the moon is made of cheese and it is true that you go to college .

But how can thoughts be about things ? How can thoughts relate to the world? How can thoughts be true or false? H ow could neurons firing in your brain be about anything? In what respect is the firing of neurons true or false? Propositions are not firing of neurons ! And firing neurons are not thoughts or propositions! How can a state in your brain have any intention?

3. Subjectivity Your conscious experiences are subjective— personal, private. They cannot be experienced by anyone else. Others can have similar experiences, but you and you alone know what it is like to taste an apple . Imagine when I taste an apple to me it tastes like banana. There is no possible way to me to tell . I cannot get inside your head. A brain surgeon can open your head and see certain activities going on, but never see what you see . What happens in your experience is inside your mind not inside your brain. But then where do these experiences and mental states occur?

4. Causation Your thoughts make your body move. You think “dinner” your body moves to the kitchen and starts cooking. But how can immaterial thoughts and desires cause anything? How can nonphysical thoughts give rise to the physical without violating the laws of the conservation of mass, of energy and of momentum? Are we supposed to believe that thoughts can grab the axons or push the dendrites of your nerve cells and make you move?

Dualism vs. Materialism

These 4 problems (Consciousness, Intentionality, Subjectivity, Mental causation) constitute the so-called mind-body problem . Mind-body problem = how the mental and the physical relate and interact. The Mind-body problem has puzzled scientists for centuries. The problem has been addressed by two distinct positions: Materialism (or physicalism ) and Dualism

Materialism (physicalism) : mental states are physical states—states of the brain, which is a physical thing. Physical things can be accounted for by physics, biology, chemistry, etc . Dualism : Mental states are not states of any physical thing; they are non -physical entities. Non -physical things cannot be investigated by the sciences.

Dualist Theories of the Mind

Substance Dualism Each mind is a distinct nonphysical thing, independent of any physical body . The brain is a physical substance The mind is a non-physical substance Descartes ’ Arguments: Matter – physical stuff – doesn’t think. A mind is a thinking thing, and thinking isn’t located in space; The mind is not matter or physical stuff. Therefore, the mind is non-physical.

Problem: modern science allows for matter that is not extended in space: Electrons are bits of matter that are best understood as “point-particles” with no determinate spatial position or mass .

Another Argument: We have thoughts, use a language, and engage in reasoning. Physical things cannot engage in reasoning. Thus, the mind is something nonphysical. Problem : Your eyes, ears, etc . cause visual/auditory/tactile experiences in your mind. Mental states, decisions, and intentions to do something cause your body to move in various ways.   How could something immaterial influence something material? Is there a break in the laws of nature governing matter? The law of the conservation of momentum?

Property Dualism There are not two kinds of substances , the mind and the brain, but two kinds of properties —physical and non-physical properties. Two kinds of property dualism : ( 1) epiphenomenalism and (2) interactionism Some Features of Both Positions Mental properties are emergent properties: they do not appear until physical matter is organized in a certain way. Mental states and properties are irreducible : they are “beyond prediction or explanation by physical science”.

1. Epiphenomenalism: Mental phenomena “ride on top of” brain processes, but don’t ever affect the brain. Mental states have no causal powers . This is unbelievable. 2. Interactionism: Mental properties, mental states, are nonphysical but interact with the brain. But how do they interact?

What motivates Dualism? Arguments for dualism:

The argument from religion :God exists. God is a mind. God is immaterial. Objection : Not all agree that God exists. Religion has a terrible track record of supporting scientific discoveries

The argument from introspection When one introspects, one finds desires, beliefs, sensations, thoughts, etc ., and not a “neural network pulsing with electrochemical activity.” Objection : None of our other senses grasp the world just as it is, and we have no reason for thinking the “sense of introspection” is any different.

The argument from irreducibility If there are mental phenomena for which no physical explanation could be given, we must conclude that the physical is not all there is. E.g.: The ability to use language, Mathematical reasoning   Objections : We have calculators/computers, that engages in mathematical calculation and languages . Besides: Scientists explain the intrinsic qualities of mental states by reference to the physical. But dualists have not shown that reducing quality to the physical is impossible; they have only said they do not see how it can be done. Suppose dualism is true. How does this help with explaining the intrinsic quality of a mental state?

The argument from personal identity Physically, I am not the same person I was at the age of 3. Every cell in my body is completely different . But then why do I have the same thoughts, memories, etc.? Because I am the same person. The body constantly changes (including the brain). The mind is consistent and therefore separate from body.   Objection : Change can be gradual and info is passed along through stages of growth.

Arguments Against Dualism

The argument from simplicity Simpler theories are, all other things being equal, better than complex theories. Materialism is a simpler theory than dualism. Materialism is, all other things being equal, a better theory than dualism.

The explanatory power of materialism Neuroscientist can explain a great deal of behavior, the workings of the brain neuron firings, chemical transmitters, brain damage, etc . The dualist can tell us nothing about this “mind stuff.” If dualism has no explanatory power, and materialism has a tremendous amount of explanatory power, we ought to endorse materialism. Thus, we ought to endorse materialism.

The argument from neural dependence If thinking, reasoning, emotion, etc . really are performed by a special mental entity, and the body simply provides sensory information (looks like, smells like, etc .), then one would expect reason, emotion, and consciousness to be relatively invulnerable to direct control or pathology by manipulation or damage to the brain. But damage to the physical brain always causes loss or change of mental functions. So the mind would seem to be physical

The argument from evolutionary history The origin of our species is explained by reference to evolution. Thus , the humans’ current constitution is the result of a purely physical process.

Four Materialist Theories: 1. Behaviorism 2. Identity Theory 3. Functionalism 4. Eliminative Materialism

Behaviorism There is no mind-body problem because claims about people’s mental states are just claims about people’s dispositions to behave in certain ways.   M ental state ( beliefs, desires, hopes, etc. ) are descriptions of behaviors that do not correspond to mind.   Objections : Its denial of the “inner” aspect of mental states: Pain, love, hunger, etc. are not just a dispositions to action; they feel a certain way. Also, such inner mental contents have causal powers to move body.

Identity Theory (or Reductive Materialism) Mental states are identical to brain states. Pain just is identical to the firing of certain neurons in a brain, For every individual mental state, there is an individual brain state identical to it. There are many scientific discoveries that have shown us various phenomena are identical to other. (Wetness of water) Objection : Mental states have semantic properties, that is, they have meanings , some of them (beliefs) can be true or false some of them (beliefs and desires) can (logically) conflict . Brain states do not have semantic properties; the firing of a certain neurons cannot be true or false, cannot (logically) conflict with other neurons firing, etc .

Functionalism : A mental state is defined by its causal relations (its function). Pain just is a state caused by damage or trauma, causes distress, thinking about stopping it, etc . A thought or desire, (or any other type of mental state) depends on its function, or the role it plays, in the cognitive system of which it is a part. Objection : We can be functionally identical but have different experiences. Therefore, a mental state cannot just be defined by its causal connections; there is also its “inner quality,” or what it is like to have that mental state, which functionalism cannot explain.

Eliminative Materialism Advances in neuroscience reveal to us that theory about the mind is a bad theory. Historical examples of a theory being eliminated: Heat was thought to be a fluid, a substance, called “caloric,” but we now know that heat is the motion of molecules. Burning and rusting was thought to be a matter of a thing called “phlogiston” leaving the object that was burning or rusting. People thought there were witches, when in fact there was just psychosis. So : The concepts psychology – belief, desire, fear, sensation, pain, joy, and so on – in time will be eliminated.

Th e E n d Questions?