Announcements

• Midterm study questions are at the tab above.  Look at them before next Wednesday, when we'll review.
• I gave you an easier option for HW13.  Check it out at the syllabus.
• There's just one homework for next week.
• See next post for info about the next movie.

Announcements

(1) Turning in bonus/replacement homework.  The old system wasn't working well. I now have week-specific assignments.  So if you turn in bonus/replacement homework this week, upload to WEEK 6 B/R, which is right next to WEEK 6 in Canvas.

(2) First annual Philosophy Department fall semester pizza party. Everyone welcome.

(3) Earthlings

Theories of Personal Identity

The Problem of Personal Identity

• What makes a human being remain the same individual, over time?  
•  For example, are you the same individual as the baby your mother gave birth to?  Will you continue to exist as a 90 year old?
• What is a human being essentially?
• Criterion of personal identity-- A = B if and only if __________________
• Could you go on existing, as the very same human being, after the death of your body?

The Still Alice problem

• Alice1 makes a video telling Alice2 to kill herself  (movie clip-- :39 - :40  and 1:23 - 1:27)
• "I'm you"....is that true?
• If Alice1 = Alice2, Alice1 is planning a suicide
• If Alice1 =/ Alice2 , then Alice1 is planning a homicide!  
• Is Alice1 planning a suicide or a homicide?

The Soul Theory (Richard Swinburne)

• We are essentially souls (attached to bodies for now)
• You will continue to exist as long as you have the same soul
• Fun fact: you weigh nothing
• Swinburne's "what else?" argument.  You could find yourself (a) in control of another body, or (b) with no body, or (c) with no memory of the past.  So what else could make you you besides an immaterial soul?
• Homework: is he arguing that the soul is immortal?
• p.s.  We talked about Christianity and the afterlife a bit.  More on that topic is here.

Movies Consistent with Soul Theory

• Freaky Friday
• Nine Lives

The Body Theory

• We are essentially bodies (in a comprehensive sense, where the body includes the brain)
• You will continue to exist as long as you have the same body (which is possible despite some degree of change)
• Fun fact: you weigh 150 pounds (or whatever)

The Brain Theory

• We are essentially brains.
• You will continue to exist as long as you have the same brain (which is possible despite some degree of change)
• Fun fact: you weigh about 2 pounds
• Brain transfer argument: if you had an accident and your brain were transferred to a new body, you would survive the accident.

Movies Consistent with the Brain Theory

The Man with Two Brains (1983)

Who is Julia? (1986-made for TV)--start at 10:43

Is this really possible?  Yes!

The Still Alice Problem (in groups, if we have time)

• What does each theory say about whether Alice1=Alice2?
• Which of these three theories is most plausible?
• What's the bottom line (on the theory of personal identity you prefer): is Alice1 plotting a suicide or a homicide?
• What do you really think it is, suicide or homicide?

Philosophy of Mind Review

(1) Substance Dualism (Rene Descartes)

• There are two substances, soul and body
• The body is extended (takes up space), the soul is unextended (doesn't take up space)
• To have mental states (like seeing red), you need a soul.  It's the soul that sees red.
• Descartes thought soul and brain interacted through the pineal gland
• Ava, in Ex Machina, couldn't have mental states unless she has a soul.

(2) Physicalism-1 (JJC Smart)

• Also known as the Mind/Brain Identity Theory or simply the Identity Theory.
• To have mental states (like seeing red), you must have a brain, and don't need a soul.  It's the brain itself that sees red. Mental states are identical to brain states.
• The biological science of the brain will eventually explain each and every type of mental state.  We will understand that feeling hot is this particular brain state, seeing red is that brain state, etc.
• Ava, in Ex Machina, doesn't have a biological brain, so couldn't have mental states.

(3) Functionalism 

• To have mental states, you don't need a soul. Mental states are functional states, likes being an alarm is a functional state.  Any system can have mental states if it functions in the right way.
• The science that explains mental states will be computer science, not brain science.
• An AI like Ava in Ex Machina, could (in principle) function so as to have mental states.

(4) Naturalistic Dualism (David Chalmers, next week)

• Easy problems about consciousness
• The hard problem
• Qualia
• Consciousness as a fundamental property
• Panpsychism
• Ava could be conscious--even your gas gauge could be conscious, to a very low degree
• Why this is called "naturalistic dualism"

(5) Epiphenomenalism (Frank Jackson)

• Jackson says that qualia are not physical
• He thinks they're caused by the physical brain they don't cause anything--your red qualia don't cause you to stop at a redlight (epiphenomenalism)
• The knowledge argument has generated many different responses (see Prof. Fisher's notes below)
• Here's an excerpt from Patricia Smith Churchland's article

• Churchland's argument: pregnancy gives the obstetrician a new window onto the same old thing--pregnancy.  Likewise, leaving the black and white room gives Mary a new window onto color vision.  However, she doesn't discover any new, non-physical feature of color vision.
• Using the typology below, which type of response is this?

-----------------------------------

Responses to the Knowledge Argument (Prof. Fisher's notes)

Type A physicalists (like Dennett, mentioned in the Chalmers video) deny P2, and hold that Mary's textbook knowledge about color vision actually would put her in position to fully anticipate what would happen in the tomato scenario, so she wouldn't be surprised at all.  If you think she would be surprised, then Dennett thinks you probably haven't really imagined what it would be like to know *all* the physical info about color vision.

Type B physicalists deny P3, holding that whatever it is that Mary gains, it isn't completely new information about color vision.  E.g., David Lewis thinks that all Mary gains is the *ability* to recognize red when she sees it again as the same color as she saw on the tomato.  Paul Churchland thinks that Mary gains info in a new part of her brain -- the visual cortex -- info which was already present in a different part of her brain -- the part which held textbook knowledge.  Since this isn't completely new info, it is no counterexample to physicalism.  These Type B physicalists think we have two different windows onto the physical events happening in our brains:  one window involves learning about our brains using third-person science; the other provides an introspective window upon the same brain events.  The fact that Mary can add info to her list of things she's seen through the second window does not in any way show that her view through the first window wasn't complete.

Type C reply is Mysterianism (advocated by Colin McGinn).  This view basically denies P1, and says that our minds are incapable of fully understanding conscious experience.  We evolved to solve certain sorts of problems that our ancestors faced, but fully understanding our brains and consciousness would involve far more brainpower than that, so we're simply incapable of doing it.  Kind of like it would be completely hopeless to for your dog to try to understand algebra, McGinn thinks it's completely hopeless for humans to try to understand consciousness.  This view may turn out to be right, but it's premature to give up hope at this early point.  Our ancestors also had no need to understand rocket ships or relativity, but we still managed to wrap our heads around those things.  Maybe we'll be able to wrap our heads around consciousness too.

Tangent.  I mentioned that, on McGinn's view, perhaps our best hope of understanding this stuff would be to build AI's that surpass our own cognitive limitations.  This led students to ask questions about (i) whether the relevant computational power is possible, (ii) about whether such a computer would have a mind, (iii) about whether we could transfer our own minds into a computer, and (iv) about whether the resulting computer would be *me* or just something with a mind a lot like mine.  I noted how question (iv) is very similar to questions that come up in the personal identity over time literature, e.g., in cases of tele-transportation.

Type D response is interactive dualism (advocated by Descartes, for example).  If minds involve non-physical stuff or properties, then this would explain why there is more info for Mary to learn about color vision, beyond the physical info.  However, David Lewis pointed out, dualism doesn't really help.  We could imagine Mary also reading textbooks about dual substances and how they interact with physical substances.  Still, the intuitions are just as strong that, until she sees red for herself, she won't know what it's like to see red.

Type E response is "epiphenomenalism" which is dualism with the interaction going only in one direction, body to mind.  This was the conclusion Jackson drew from the Mary argument.  Jackson thought that the Mary argument showed that there is something non-physical, and he was confident that conscious events (like pain) were caused by physical events (like getting hit with a hammer).  However, since physicists couldn't find any evidence of any physical events being caused in weird ways, Jackson concluded that the interaction didn't go in the other direction.  This means that whatever behavior people produce (including every single claim they utter about consciousness), this is produced by their *brains*, not by their separate conscious minds.  It's a lucky coincidence that the same time as our minds decide to do things, our brains also just happen to send out the right motor commands to do them. 

Type F response is Chalmers own preferred view, "pan-psychism", which holds that even the most basic physical elements have, as part of their nature, some limited form of consciousness, and that these limited forms of consciousness can lead to higher forms of consciousness when physical elements get arranged into brains.  Mary's black-and-white education would leave out these conscious aspects of the basic physical elements, so that's why there's more info for her to gain when she sees her first tomato.  The Jackson-style argument that Lewis used against dualism (imagine Mary learns all about dual substances in her room -- that still wouldn't tell her what red would look like) arguably doesn't work against pan-psychism -- if Mary were to learn all about the conscious aspects of physical stuff, and how these combine to form higher forms of cons, this really would tell her what it feels like to see red.  However, this view is faced with many of the same problems as the two dualisms, explaining how these psychic properties interact with ordinary physical properties and why they seem to interact if they don't, and explaining why we should believe in all these weird properties without any physical evidence of their existence.

Can Consciousness Be Explained?

You'll be watching two videos today (we'll discuss them Wednesday).  Please turn in the worksheet at the end of class, to get credit for attendance.

First video--Nancy Kanwisher--Neuroscientist at MIT




Second video--David Chalmers--Philosopher at NYU
Note: he's the author of today's reading

Philosophy as a Pre-Law Major

Ex Machina Discussion

Announcements

• No office hours today
• Philosophy and Pre-Law Event Next Week

Ex Machina

Get into groups.  Discuss all of the mind questions.  Then discuss one of the Ethics/Gender/Sexuality questions.  Pick a spokesperson.

Mind Questions

1. Is the Original Turing Test (are Ava's answers distinguishable from a human's?) a good test for consciousness and mind?
2. Is the New Turing Test (can Ava get Caleb to help her escape?) a better test for consciousness and mind?
3.  Does Ava appear to lack any capacity that's crucial for real consciousness and mind?

Ethics/Gender/Sexuality Questions

1. Is it wrong for Nathan to turn off Ava when he develops a new model?
2. Do the AIs in the movie have rights?
3. Could AIs really have genders?
4. Is it wrong for Nathan to use the AIs for sex?

***

5 PHILOSOPHIES OF MIND

(1) Substance Dualism (Rene Descartes)

• To have mental states (like seeing red), you need a soul.  It's the soul that sees red.
• Descartes thought soul and brain interacted through the pineal gland
• Ava, in Ex Machina, couldn't have mental states unless she has a soul.

(2) Physicalism (JJC Smart)

• To have mental states (like seeing red), you must have a brain, and don't need a soul.  It's the brain itself that sees red. Mental states are identical to brain states.
• The biological science of the brain will eventually explain each and every type of mental state.  We will understand that feeling hot is this particular brain state, seeing red is that brain state, etc.
• Ava, in Ex Machina, doesn't have a biological brain, so couldn't have mental states.

(3) Functionalism 

• To have mental states, you don't need a brain or a soul. Mental states are functional states, likes braking is a functional state.  Any system can have mental states if it functions in the right way.
• The science that explains mental states will be computer science, not brain science.
• An AI like Ava in Ex Machina, could (in principle) function so as to have mental states.

(4) Naturalistic Dualism (David Chalmers, next week)

(5) Epiphenomenalism (Frank Jackson, next week)

Mental Events and Physical Events

MENTAL EVENTS

JJC Smart's favorite example of a mental event: seeing an after image.

Stare at the white cross for 35 seconds. Then look at the white board.
http://www.optical-illusionist.com/illusions/butterfly-afterimage

PHYSICAL EVENTS

ARE ALL MENTAL EVENTS (QUANTITATIVELY) IDENTICAL TO PHYSICAL EVENTS?

1. Quantitatively identical--like Superman is identical to Clark Kent.  There's one person, not two.
2. Qualitatively identical--like identical twins are identical to each other. There are two people, but they are very much alike.

SUBSTANCE DUALISM

Mental events are NOT identical to physical events, but rather, occur in a non-physical soul. (Descartes's view)

PHYSICALISM

Mental events ARE identical to physical events, and occur in the brain. (JJC Smart's view)

ARGUMENTS

On the board.... 

Submitting Homework

(1)  Required--one per week (lowest score dropped).

• Please upload to the right week at Canvas!  I've made it clearer by listing the homeworks for each week. 
• Please write the week and homework at the top of your homework.  For example:  Week 5, HW8.

(2) Replacement--you got a zero on Monday's homework (for example), so submit more homework Wednesday.

• Submit this at the first available Bonus/Replacement assignment. 
• At the top of the assignment, write the week and homework assignment, and say that what you're trying to replace.  For example:  Week 5, HW9, replacing HW8.
• If you get credit, you will see the credit at Week 5. It will say 0 here, to avoid giving you double credit!

(3) Bonus--you turned in the required homework and got credit, but want to do more for extra points.  

• You'll submit this at the first available Bonus/Replacement assignment.
• At the top of the assignment, write the week and homework assignment, and say "bonus." For example: Week 5, HW9, bonus
• If you get credit, you'll see 100 here.  If you don't, you'll see 0.
• You'll get an extra homework point at the end of the semester, for each bonus assignment you do (up to 10).  Canvas can't add these points automatically--I'll do it manually at the end of the semester.

Ex Machina plus Syllabus Revision

We'll have a quiz on the movie Ex Machina on Friday.  More info and links here.

This coming week is week 4. The syllabus for next week, week 5, has been revised.  It's a good idea to use the online syllabus to find out the reading assignment and homework.  It will always be current.

Announcements

1. A student in this class needs copies of two classmates' notes. If you take good notes and are willing to share a copy of them with a classmate, please meet me after class to make arrangements.
2. Our next movie is Ex Machina--we'll have a quiz on it on Friday September 16.
3. Read all the homework rules on the syllabus and bear in mind that you just have to do a conscientious job to get credit. That means (a) answering the whole question (all parts), (b) using the reading to the extent relevant to the question, (c) writing enough words to cover the topic (usually 100-200), (d) writing thoughtfully.  The point of the homework is to incentivize you to do the readings with reasonable care and to prepare you to contribute to class discussion. 

Solution #5: Reliabilism

JTB Definition of Knowledge

x knows that p if and only if

1. x believes that p
2. p is true
3. x is justified in believing that p

Is this definition right?  Would a different definition help us overcome our evil deceiver worries?
Edmund Gettier--definition is not right because the three conditions are not jointly sufficient

Before looking at counterexamples--

1. Forget about the evil deceiver, make common sense judgments.
2. Justification is one thing, truth is another.
3. Justification spreads through logical reasoning.  If you're justified in believing that p, and you know that p logically entails q, then you're justified in believing that q.

Gettier Case I, in cartoon form:

Credit: this is a modified version of an SMBC cartoon by Jack Weinersmith.
 http://www.smbc-comics.com/index.php?db=comics&id=2458

Credit: this is a modified version of an SMBC cartoon by Jack Weinersmith.
http://www.smbc-comics.com/index.php?db=comics&id=2458

Henry and the Barns

1. Henry believes he's looking at a barn
2. He is in fact looking at a barn.
3. He's justified in believing he's looking at a barn.

But because of all the fake barns in the area, Henry doesn't know he's looking at a barn! So the JTB definition is not right!

Broken Clock Counterexample (more realistic!)

The clocks in Hyer Hall were broken all last year.  Imagine Sally doesn't know this. She comes into Hyer Hall, looks at the clock, and sees it says 12:00.  She thus believes that it's 12:00.  But note: she would have believed the same thing had it actually been 11:00 or 1:00.

1. Sally believes it's 12:00
2. It is in fact 12:00
3. Sally is justified in believing it's 12:00

Sally meets all three conditions but she doesn't know it's 12:00!  So the JTB definition is not right!

New "reliabilist" definition of knowledge:

x believes that p if and only if

1. x believes that p
2. p is true
3. under the relevant circumstances x is reliably correct on the topic of p

Being reliably correct in the relevant circumstances vs. having justification

• Having justification is having reasons, evidence, being able to explain why you believe that p
• Being reliably correct is just getting it right, under the circumstances

On this definition, why doesn't Smith know? Why doesn't Henry know? Why doesn't Sally know?

How is this going to help us with the evil deceiver?  Stay tuned!

• Monday we'll talk about this
• We will also talk about how Descartes thought he'd solved the evil deceiver problem

Solving Descartes's Problem

Announcements

• Week 2 homework grades and comments will be in Canvas this afternoon.
• We'll discuss homework expectations on Friday.

Descartes's Problem

Truman's Problem

Solution #1 -- No Solution

Skepticism about knowledge of the external world.  Descartes can't know there's a fire. He can't know anything about matters outside of his own mind.



Solution #2 -- Doing Experiments


 


Truman's reasoning:  

(1) Either my world is natural or it's fabricated by strange forces 

(2) If it were natural, and I did X (e.g. drove in an atypical direction), then I would observe Y (e.g. the usual cars). 

(3) But when I do X (e.g. drive in an atypical direction), I don't observe Y (e.g. the usual cars). 

So (4) My world is fabricated by strange forces.

What experiment could Descartes do to prove that either there is or isn't an evil deceiver?  If this sort of solution could work for Truman, could it work for Descartes?

Could Descartes experiment and reason in a similar way?

(1) Either the fire image in my mind is caused by a real fire or it's caused by an evil deceiver. 

(2) If if were caused by an evil deceiver and I did X, I would observe Y. 

(3) But when I do X, I don't observe Y. 

So (4) The fire image in my mind is caused by a real fire.

GROUPS:  SEE IF YOU CAN COME UP WITH X AND Y FOR DESCARTES. 


Solution #3: Jonathan Vogel's "Explanationist" Solution

The Deceiver Argument.  (This is the argument that disturbs Descartes in Meditation I.  The skeptic thinks it's a sound argument.)

Vogel says The Deceiver Argument is unsound.  Why is it unsound?  Because (he says) premise (2) is false.  He talks about a couple of other accounts of why it's false and then presents Explanationism as his own reason.  

Explanationism. Descartes has two competing hypotheses to explain his mental image of the fire, but Vogel says they are not equal.  One is a better hypothesis than the other. So Descartes has reason to choose the better of the two. This is known as "inference to the best explanation" and we use this sort of reasoning all the time. If Vogel is right here, then premise (2) of the Deceiver Argument is false.

Vogel uses the examples below to convince us that there are better and worse hypotheses:

Ex. 1.  Dr. G sees his patient Roger and has two hypotheses about what's causing his symptoms.  

1. allergy hypothesis (better because generalizes to other cases)
2. something else hypothesis (worse because ad hoc)

Ex. 2.  Two people are debating why you reach the same location, if you keep traveling in the same direction

1. round earth hypothesis (better because simple)
2. flat earth hypothesis--you'll be drugged and abducted by aliens to get from one edge to the opposite edge (worse because needlessly complicated)

Back to Descartes! Why is the fire dying down?   Descartes will struggle between two hypotheses--

via GIPHY

1. real world hypothesis--log is being consumed (Vogel says: better because simpler)
2. evil deceiver hypothesis--ED is generating a sequence of flame images, each smaller than the previous one (Vogel says: worse because needlessly complicated)

Since the real world hypothesis is superior, premise (2) of the Deceiver Argument is false.

Solution #4: Descartes's Very Own Solution 

We will talk about this solution more on Monday 9/12.  Friday we will go on to the next reading.  

Solution #5: Reliabilist Approach

We'll talk about this solution Friday 9/9.