Human Nature 2.3 Human Nature 2.3

The Mind-Body Problem: How Do The Mind-Body Problem: How Do

Mind and Body Relate?Mind and Body Relate?

The Mind-Body Problem: How Do The Mind-Body Problem: How Do Mind and Body Relate?Mind and Body Relate?

To most of us it is obvious that we have a To most of us it is obvious that we have a mind and a body. But, the mind’s mind and a body. But, the mind’s subjective consciousness is puzzling. subjective consciousness is puzzling.

Moreover, those who accept that the mind Moreover, those who accept that the mind and the body are distinct are faced with a and the body are distinct are faced with a problem; problem; how can a non-physical object how can a non-physical object interact with a physical one?interact with a physical one?

Other people hold that only the physical Other people hold that only the physical exists.exists.

The Dualist View of Human The Dualist View of Human NatureNature

Rene Descartes Rene Descartes held that held that the mind and the body were distinctthe mind and the body were distinct, ,

since we can conceive of the mind existing since we can conceive of the mind existing without the body. without the body.

On this view, humans are made up of two On this view, humans are made up of two substances.substances.

Problem: Problem: how can an immaterial mind move a how can an immaterial mind move a physical body, and how can a physical body physical body, and how can a physical body affect an immaterial mind? affect an immaterial mind?

Descartes held that since mind and body Descartes held that since mind and body obviously interact there must be a obviously interact there must be a point of point of contactcontact between them; between them; the pineal glandthe pineal gland. .

The Dualist View of Human The Dualist View of Human NatureNature

Not everyone accepted Decartes view, Not everyone accepted Decartes view, Gottfried LeibnizGottfried Leibniz held that the mind held that the mind

and body don’t really interact at all, but and body don’t really interact at all, but only appear to.only appear to.

MalebrancheMalebranche held that God held that God synchronizes their apparent synchronizes their apparent interactions. interactions.

The Materialist View of Human The Materialist View of Human naturenature

Hobbes Hobbes the problem with dualism was that it held that the problem with dualism was that it held that

there are two things in human nature. But, let us there are two things in human nature. But, let us say that there is only one: say that there is only one: the material bodythe material body. The . The operations of the mind will then be explained in operations of the mind will then be explained in terms of the workings of the body. terms of the workings of the body.

This view holds that processes such as thought This view holds that processes such as thought and life are just and life are just physical or chemical processesphysical or chemical processes is is often called often called reductionismreductionism: the idea that we can : the idea that we can completely understand one kind of reality in completely understand one kind of reality in terms of another kind. terms of another kind.

Problem with this view is that it is not clear how Problem with this view is that it is not clear how physical phenomena can produce mental physical phenomena can produce mental phenomena.phenomena.

The Mind/Brain Identity Theory The Mind/Brain Identity Theory of Human Natureof Human Nature

One kind of contemporary materialist view is the One kind of contemporary materialist view is the identity theory of the mind: that identity theory of the mind: that states of states of consciousness are identical with states of the consciousness are identical with states of the brainbrain. .

This view is held by J.J.C. Smart. This view is held by J.J.C. Smart. Problems: Problems:

Brain states are publicly observable, but mental states Brain states are publicly observable, but mental states are not. are not.

Moreover, a mental experience has no location, no color, Moreover, a mental experience has no location, no color, and no shape. So, how can brain states and conscious and no shape. So, how can brain states and conscious states be the same, since they are such very different states be the same, since they are such very different things? things?

The Behaviorist View of Human The Behaviorist View of Human NatureNature

Behaviorism is the view that mental Behaviorism is the view that mental activities can be explained in terms of activities can be explained in terms of behavior. behavior. For example, For example, Gilbert Ryle held that Gilbert Ryle held that mental activities could be mental activities could be

explained in terms of the activitiesexplained in terms of the activities that they are that they are associated with. Thus, to say that John knows associated with. Thus, to say that John knows that a chair is near is to say that he will behave that a chair is near is to say that he will behave in certain ways, such as sitting in it. in certain ways, such as sitting in it.

- Hilary Putnam has argued that it is easy to come - Hilary Putnam has argued that it is easy to come up with examples that show that behaviorism is up with examples that show that behaviorism is wrong, such as when one acts as though one is wrong, such as when one acts as though one is in pain; one is not actually in pain, despite in pain; one is not actually in pain, despite showing the appropriate behavior. showing the appropriate behavior.

The Functionalist View of The Functionalist View of Human NatureHuman Nature

Another view of human nature is functionalism. This holds Another view of human nature is functionalism. This holds that we should explain mental activities and mental states that we should explain mental activities and mental states in terms of perceptual inputs and behavioral outputs. in terms of perceptual inputs and behavioral outputs.

Mental states and activities refer only to the functions they Mental states and activities refer only to the functions they serve in the processes that connect our sensory inputs to serve in the processes that connect our sensory inputs to our behavioral outputs. our behavioral outputs.

Functionalism allows that mental states can explain other Functionalism allows that mental states can explain other mental states; a person’s intention, for example, can be mental states; a person’s intention, for example, can be explained in terms of her desires and beliefs. explained in terms of her desires and beliefs.

The intention is then something that plays the role of The intention is then something that plays the role of linking the sensory stimulation to the desire to perform a linking the sensory stimulation to the desire to perform a certain action in light of it. certain action in light of it.

But the functionalist seems to leave something out; the But the functionalist seems to leave something out; the inner conscious states that we are aware of. inner conscious states that we are aware of.

The Computer View of Human The Computer View of Human NatureNature

Functionalism has led some philosophers to Functionalism has led some philosophers to believe that the human brain is a kind of believe that the human brain is a kind of computer. Some have also argued that when computer. Some have also argued that when computers can process inputs and outputs like computers can process inputs and outputs like the human brain does, they will be able to the human brain does, they will be able to think. think.

Alan Turing held that if a computer was so Alan Turing held that if a computer was so powerful that we could not tell the difference powerful that we could not tell the difference between its answers and those of a human between its answers and those of a human being, the computer has a mind. being, the computer has a mind.

John Searle opposes this view of John Searle opposes this view of human nature, holding that humans human nature, holding that humans have consciousness that computers have consciousness that computers lack. But Searle is not a dualist; he lack. But Searle is not a dualist; he believes that humans are merely believes that humans are merely physical creatures; although the physical creatures; although the mental states that the physical states mental states that the physical states produce are not reducible to physical produce are not reducible to physical things.things.

Eliminative MaterialismEliminative Materialism

Many philosophers believe that only Many philosophers believe that only matter exists—and, given the matter exists—and, given the difficulties faced by the monistic difficulties faced by the monistic views outlined here, eliminative views outlined here, eliminative materialists hold that we should materialists hold that we should eliminate our belief in the existence eliminate our belief in the existence of consciousness. of consciousness.

The New DualismThe New Dualism

New dualists hold not that there are New dualists hold not that there are two different kinds of substances in two different kinds of substances in the universe, but that the universe, but that there are two there are two different kinds of propertiesdifferent kinds of properties. .

These dualists hold that These dualists hold that consciousness isconsciousness is not a physical not a physical feature of the world, but feature of the world, but a a nonmaterial property of it. nonmaterial property of it.