Chapter 2 The Mind-Body Problem McGraw-Hill © 2013 McGraw-Hill Companies. All Rights Reserved.

2.1-2 The Mind-Body Problem  How is it possible for the mind to affect the body given that the mind seems non- physical?  What is it to have a mind?  Can non-living things like robots or computers have minds?

2.1-3 Bodies and Minds  What goes on in our bodies can be explained in physical terms, as the result of various electrochemical or biomechanical interactions.  But what about what goes on in our minds? Can our thoughts be explained physically?

2.1-4 Thought Experiment: Descartes' Mechanical Moron  Can we construct a machine that thinks?  Descartes claims that no machine would be able to use language or solve problems like we do.  Do you agree? Why or why not?

2.1-5 Thought Experiment: Leibniz’s Mental Mill  Suppose that we created a machine that thinks, and suppose further that we were able to walk around inside the machine.  Leibniz claims that explaining the working of the parts of the machine would not explain its thinking.

2.1-6 Thought Probe: Walking Around Inside the Brain  Suppose you were able to walk around inside a brain, like the crew from the movie Fantastic Voyage.  Would you observe thinking?

2.1-7 Thought Probe: Artificial Intelligence  If further research into artificial intelligence may result in the extinction of the human race, should it be allowed to continue?  Should we try to ban it? How?  What if one nation banned it and others didn’t?

2.1-8 Theories of Reality  Idealism: the doctrine that minds and their contents are all that exists.  Materialism: the doctrine that material objects are all that exists.  Dualism: the doctrine that reality contains both mental and material things.

Section 2.1 The Ghost in the Machine Mind as Soul

Cartesian Dualism  Cartesian dualism is the doctrine that mental states are states of an immaterial substance that interacts with the body.

Descartes’s Doubt  We know something only if it’s certain.  Most of what we think we know is based on sense experience.  But we can’t be certain of anything we’ve learned through sense experience.

Thought Experiment: Descartes’s Dream Argument  “How often has it happened to me that in the night I dreamt that I found myself in this particular place…while in reality I was lying undressed in bed.”  Can you be certain that you’re not dreaming right now? If so, how?

Thought Experiment: Descartes’s Evil Demon  “How do I know that [an evil demon] has not brought it to pass that there is no earth, no heaven, no extended body, no magnitude, no place, and that nevertheless they seem to me to exist just exactly as I now see them?”  Can you be certain that there is no such demon?

Thought Probe: Living in the Matrix  Can you be sure that you’re not living in a computer simulation such as that portrayed in the movie, The Matrix?  If so, how?  If not, does that mean that you can’t have knowledge of the external world?

“I think, therefore I am.”  Descartes cannot doubt that he is thinking, for doubting is a type of thinking. To doubt is to think.  And Descartes can’t doubt anything unless he exists.  So Descartes claims that he can be absolutely certain of one thing, namely, “I think, therefore I am.”

The Conceivability Argument 1.It’s conceivable for me to exist without having a body. 2.Whatever is conceivable is possible. 3.Therefore, it’s possible for me to exist and not have a body. 4.If it’s possible for me to exist without having a body, then having a body is not essential to me. 5.Therefore, having a body is not essential to me.

The Conceivability Argument 6.It’s inconceivable for me to exist without having a mind. 7.Whatever is inconceivable is impossible. 8.Therefore, it’s impossible for me to exist and not have a mind. 9.If it’s impossible for me to exist without having a mind, then having a mind is essential to me. 10.Therefore, having a mind is essential to me.

Cartesian Dualism  Descartes has proven that he is a thing that thinks.  But physical things, he claims, cannot think.  So, he concludes, he (his mind) is a non- physical thing.

Thought Probe: Descartes and Vivisection  Descartes believed that only humans had souls because, among other things, animals can’t reason the way that we do.  Some followers of Descartes took this to mean that animals have no mental states at all, not even pain.  Does our mental superiority give us the right to use animals as we please? Why or why not?

Thought Probe: Heaven without Bodies  Suppose that you have an immaterial soul, and suppose that it goes to heaven when you die.  Immaterial souls have no physical properties; they can’t be seen, touched, smelled, etc.  How would you recognize your loved one’s? How would you communicate with them?  Would going to a heaven full of immaterial souls be something to look forward to?

Indiscernibility of Identicals  According to the the indiscernibility of identicals, if two things are identical, then they must both possess the same properties.  For example, if Mark Twain is identical to Samuel Clemens, then whatever is true of Mark Twain is true of Samuel Clemens and vice-versa.

The Divisibility Argument 1.If minds are identical to bodies, then whatever is true of minds is true of bodies, and vice versa. 2.But minds are indivisible and bodies are divisible. 3.Therefore, minds are not identical to bodies.

The Problem of Interaction  Descartes believes that our minds affect our bodies, and vice versa.  But how can a non- physical object affect a physical one?

Parallelism  One way to deal with the problem of interaction is to say that the mind and body only seem to interact with each other.  According to parallelism, mental processes and physical processes run parallel to each other but do not interact.

Occasionalism and the Pre-established Harmony  Occasionalism is the parallelist theory of the mind that claims the correlation between mental and physical events is produced on each occasion by God.  Pre-established harmony is the parallelist theory of mind that claims that the correlation between mental and physical events was established by God at the beginning of the universe.

The Causal Closure of the Physical  According to the causal closure of the physical, no physical effect has a non- physical cause.  Descartes’ dualistic interactionism violates this principle.  So what is the relationship between minds and bodies?

Epiphenomenalism  According to epiphenomenalism, the mind is an ineffective by-product of physical processes.  On this view, minds are to bodies as smoke is to fire.  Physical events cause mental events but mental events do not cause physical events.

Thought Probe: Mental Relay Stations  Dualists do not believe that we think with our brains.  So what is the function of the brain? To serve as a mental relay station between the mind and body?  Have people with brain damage or Alzheimer’s disease suffered no cognitive impairment?

The Problem of Other Minds  Cartesian minds can’t be sensed because they have no physical properties.  If minds can’t be sensed, how can we know that other people have minds?

Solipsism  If one can’t know that other minds exist, maybe they don’t.  Solipsism maintains that there is only one mind in the universe, namely one’s own.