MATERIALISTS (PHYSICALIST) #4 ELIMINATIVE MATERIALISTS

MATERIALISTS (PHYSICALIST)

#4 ELIMINATIVE MATERIALISTS

• Eliminative materialists don’t believe in the mind. What do they believe in?

• What do you think of eliminative materialism?

• Why do they not believe in the mind, but believe in our brain?

• Can we rely on experience and sensation?

EPISTEMOLOGY:

THE THEORY OF KNOWLEDGE

1. How will we know when our beliefs are true? What are the criteria for having knowledge?

2. What is truth? What kinds of truth are there?

KNOWLEDGE: THREE KINDS

1. Knowledge by acquaintance (knowing someone/thing, familiarity)• I know Mr. Galindo.

2. Knowing how (competence, skill) • I know how to read.

• I know how to get an “A” in Mr. Galindo’s class.

3. Propositional knowledge (know that)• I know that apples are fruits.

• I know that reading the handouts will help me get an “A” in class.

• I know that Mr. Galindo is a big Golden State Warriors fan and is really upset

that they lost to the stupid Phoenix Suns over the weekend.

• In Western philosophy, we are almost always concerned with #3

TEST: KNOWLEDGE

What type of knowledge is indicated in underline below:

(A) by Acquaintance, (H) How, or (P) Propositional?

1. “2+2=4,” I know that for a fact.

• P

2. I used to know Peter very well but in recent times we have grown apart.

• A

3. I’m not afraid to cheat on my exams because I know how to cheat without getting caught.

• H

4. You might know something that is in your accounting book, but this doesn’t mean that you know anything about running an accounting firm.

• H

5. I’m sorry your poodle died. I know how you feel. I lost a Barbie doll once.

• A

6. I know Jenny has very large hands.

• P

KNOWLEDGE VS. BELIEFS

• What’s the difference between knowledge and belief?

• Can believing strongly that something is true, make it true?

I really believe Timmy got an A.

DOES TRUE BELIEF = KNOWLEDGE?

“This planet in our solar system has the most moons.”

Jane believes the answer is Jupiter.

Jane guesses right.

Was this knowledge?

KNOWLEDGE: CLASSICAL DEFINITION

• Someone (S) knows that something (P) is true if and only if:• (1) S believes that P is true

• (2) P is true

• (3) S is justified in believing that P is true

• One has to have reasons or evidence of some kind to establish that the belief is true.

• Knowledge is justified true belief.

CAN YOU KNOW ANY OF THE

FOLLOWING? • I know that the Bible contains God’s word.

• I know that killing people is wrong.

• I know that George Washington was a US president.

• I know that dinosaurs existed on the earth in the past.

• I know that there are at least 8 planets in our solar system.

• I know that Michael Jackson was an emotionally troubled man.

What kind of justification, if any, is possible to know that any of these statements are true?

THE MAJOR THEORIES OF KNOWLEDGE

How can we justify our belief as being true?

1. Skepticism

• You can’t.

2. Rationalism

• Through reason and logic.

3. Empiricism

• Through your sense experiences.

EMPIRICISM

• Beliefs can be justified only through sense experience.

• All knowledge is a posteriori (gained after experience).

• Mind is a passive receiver of sense experience.

• Seems like the most common sense approach.

EMPIRICISM

All of our knowledge comes through the use of the senses.

The external world causes visual perception which gives us knowledge.

EMPIRICAL TRUTHS

Examples:

• John’s car is blue.

• The door to this room is shut.

• I received an F on the midterm.

But what’s wrong with trusting your senses?

PROBLEMS WITH EMPIRICISM

1. Perception

• Problem depending on your “philosophy of perception”

1. Naïve realism

2. Indirect Realism/Representationalism

3. Idealism

2. Induction

3. Causation

PROBLEMS WITH EMPIRICISM

How was this explored in the Bill Clinton Story?

Perceptions Induction

I swear to tell the truth, the

whole truth and nothing but the

truth.

Defense objects! The witness has

just perjured himself!

On the grounds that he doesn’t know what the truth is.

Causation

PROBLEMS WITH EMPIRICISM

How was this explored in the Bill Clinton Story?

1. Truth/Knowledge based on perceptions can be deceiving.

Perceptions

“Is there a red, white and blue flag in the courtroom? How can you be

sure?” – Der.

PROBLEMS WITH EMPIRICISM

How was this explored in the Bill Clinton Story?

2. Subjectivity: We all don’t have the same perceptions.

“Is there really a red, white and blue

flag in the courtroom?” – Der. Mr.

Charles

I don’t know.

Perceptions

PROBLEMS WITH EMPIRICISM

How was this explored in the Bill Clinton Story?

2. Subjectivity: We all don’t have the same perceptions.

Perceptions

“Is there really a red, white and blue

flag in the courtroom?” – Der.

No. It’s red, white, and green.

PROBLEMS WITH EMPIRICISM

How was this explored in the Bill Clinton Story?

3. Can’t trust majority perceptions.

Perceptions

“Is there really a red, white and blue

flag in the courtroom?” – Der.

Psychology says this happens all the time.

Magicians know this well.

PROBLEMS WITH EMPIRICISM

How was this explored in the Bill Clinton Story?

1. Perceptions can be deceiving.

2. Subjectivity: We all don’t have the same perceptions.

3. Can’t trust majority perceptions.

Groups Discussion

How did Locke address these issues?

Perceptions

EMPIRICISM:

Philosophy of Perception #1

Naïve Realism

• Naïve Realism: • What you see is what you get.

• What we perceive of an object is a property of an object (size, color, taste smell, etc…).

• Issues:• Mirages, Perceptual illusions

• Example: As you walk closer to an object does it really get larger?

• Subjectivity of experiences (hot/cold, color, taste)

EMPIRICISM:

Philosophy of Perception #2 Indirect realism (Representationalism)

• So how do we account for our false or inconsistent perceptions?

• Indirect realism: What you see is not always exactly what you get.

JOHN LOCKE:

INDIRECT REALISM

(1632 – 1704) English Philosopher

� Tabula Rasa:

� Believed the mind begins as a blank slate, without any pre-existing knowledge.

� Believed all knowledge is derived from experiences which fills our slate.

� Has a character named after him in Lost

� Q: How do we account for differences (inconsistencies) in experiences?

PRIMARY AND SECONDARY

PROPERTIES

There are two kinds of Properties.

1. Primary Properties are those that really do exist in the bodies themselves.

• Shape, Solidity, Extension, Motion or Rest, Quantity

2. Secondary Properties are those that do not really exist in the bodies themselves.

• Tastes, Colors, Sounds, Odors, and certain Feelings of Touch, like softness or roughness.

Shape: yes

Color: no

EMPIRICISM: INDIRECT REALISM (REPRESENTATIONALISM)

John Locke’s Representationalism:

• We experience both primary and secondary qualities of the external world.

• Our experience of secondary qualities are in us, not in the external world (this explains differences subjective experiences).

• We can know about the world because we experience primary qualities of external objects and secondary qualities must come from somewhere.

But is this last statement true?

Issues with Representationalism:

• How do we know if our perceptions of primary qualities of an object accurately correspond to the object itself?

• Berkeley: Do we really have experiences of the “external” world?

Locke’s Theory of Knowledge

Water itself Idea of the water

The idea of the water corresponds to a real objects.

MindReality

Berkeley’s theory of Reality

Mind

Idea of the water

Ideas exist only in mindsAll things are ideas

Therefore, all things exist only in minds

Berkeley argues that there is nothing more to an object than the qualities we perceive (the idea).

We can never perceive the causes of things we perceive.

EMPIRICISM:

Philosophy of Perception #3 Idealism

Berkeley’s Idealism:

• We do not directly experience reality. We only directly perceive our sense impressions of reality.

• So the only thing we experience are sensations (ideas).

• Since all knowledge comes through experience, the only thing real must be ideas.

Issues with Representationalism:

• Wait a minute. Then how can we use empiricism to justify knowledge if all we can know are our own ideas?

GROUP DISCUSSION

1) Reflect back on eliminative materialism. What is the relationship between empiricism and eliminative materialist argument?

2) Based on the reading and our class discussion of empiricism, how can one argue that empiricism leads to a denial of eliminative materialism?

PROBLEMS WITH EMPIRICISM

Induction = moving from particular knowledge to general knowledge (source of scientific knowledge).

Example:

Perceptions Induction Causation

This apple fell from a tree.

This apple fell from a tree.

This apple fell from a tree.

General Knowledge:

Unless something grabs them, allapples fall from trees.

PROBLEMS WITH EMPIRICISM

• General Knowledge = All apples fall from trees.

• Here’s the problem:• An empiricist can’t make that statement. They never see what “all

apples do.” (general knowledge)• We only see what a particular apple does/did. (particular knowledge).• Empiricists can not justify general knowledge from particular

knowledge.

• Think of other general knowledge:• All brains have brain cells.• The shortest distance between two points is always straight line.• In California, it is warmer in the summer than it is in the winter.

Induction

PROBLEMS WITH EMPIRICISM

• David Hume’s famous example:

• “Will the sun come up tomorrow?”

• “Yes.”

• “How do we know?”

• “Because it’s come up everyday that I can remember.”

• We don’t know that it will come up tomorrow. We just know it has come up everyday that you can remember.

Hume: “General knowledge is only habit of belief.”

Induction

PROBLEMS WITH EMPIRICISM

We are dependent on the laws of cause and effect.

Give me some examples…

Perceptions Induction Causation

PROBLEMS WITH EMPIRICISM

Hume: But if we are real empiricists, we can’t say cause and effect exists.

Why not?

• You never see it.

• You only see one event followed by another event.

• You never see one event “cause” another.

Causation

PROBLEMS WITH EMPIRICISM

Causation

LET’S THINK ABOUT THIS

• Do you need to see all apples fall from trees to know that they all eventually will?

• Do you need to look at all brains to know that brains are made out of brain cells?

• Do you need to look at all two points to know that the shortest distance is always a straight line?

• Why?

• Reason