The Idea Theory - PowerPoint Presentation

Slide1

The Idea TheorySlide2

The Conformal TheorySlide3

Aristotle

Lived in Greece

384-322 BCE

Student of Plato at the Academy

Taught Alexander the Great

Started his own school, the LyceumTowering figure in Western philosophy and ChristianityAccording to Aristotle, substances are composed of matter + form. Slide4

Hylomorphism

Greek words ‘

h

ule

’ (matter) + ‘

morphe’ (form)The doctrine is sometimes called Aristotle’s matter-formism.

Introduced to understand some issues with identity over time.Slide5

What’s the Same? What’s Different?Slide6

Essential vs. Inessential FormSlide7

Aristotle’s Psychology

The soul is the form of the body

.

Asking whether the soul = the body is like asking whether the bronze statue = its shape.

Maybe, maybe not, but it’s not of deep philosophical importance.Slide8

The Heirarchy

of

Ensouled

Beings

Intellectual Soul

Perceptual Soul

Nutritive SoulSlide9

The Conformal Theory

W

hen an animal perceives a thing, “it is made like it and is such as that thing is” (

De Anima

ii 5, 418a3–6).

Aristotle also holds a similar view, identifying the form of the knower and the thing known.

This is an obscure doctrine.Slide10

Conformal Theory: Literal Interpretation

PerceivesSlide11

Conformal Theory: Literal Interpretation

PerceivesSlide12

Linguistic Representation

Aristotle thought that spoken language was an outward sign of the state of one’s soul.

So the (spoken) word ‘house’ was a sign of my soul having the form of a house. Slide13

Linguistic Representation

So we can say that ‘house’ represents houses, because it is a sign of a state of my soul that represents houses (by identity of form with them). Slide14

Some Problems

[First let students talk.]

If my eyes have the same form as a house when I see a house, how come people looking at my eyes don’t see houses?

If my eyes have the same form as a house when I see a house, and having-the-same-form is representing/ perceiving, then how come the house doesn’t represent/ perceive me.

If I’m looking at your eyes and you’re looking at my eyes, what form do our eyes have?Slide15

Aquinas and the Conformal Theory

St

. Thomas

Aquinas (1225-1274

CE)

Doctor of the Church, Catholic Church’s greatest theologian and philosopher.Tried to synthesize Aristotle with Christianity.Tried to elaborate the conformal theory and deal with some of the problems.Slide16

Aquinas and the Conformal Theory

Elaboration of the theory:

The house-form was not “really” present in my eyes, it was only “spiritually” present.

Spiritually present forms represent really present ones, but not vice versa.Slide17

Conformal Theory: Aquinas’ Interpretation

Perceives

Spiritual Form

Real FormSlide18

Does That Solve The Problems?

If my eyes have the same form as a house when I see a house, how come people looking at my eyes don’t see houses?

If my eyes have the same form as a house when I see a house, and having-the-same-form is representing/ perceiving, then how come the house doesn’t represent/ perceive me.

If I’m looking at your eyes and you’re looking at my eyes, what form do our eyes have?Slide19

New Science, New Problems

The

17

th

Century saw the rise of

corpuscularianism. It was a lot like Greek atomism, except whereas atoms are essentially indivisible, corpuscles could theoretically be divided.

Notable

corpuscularians

were…Slide20

Robert Boyle, 1627-1691Slide21

Isaac Newton, 1643-1727Slide22

Thomas Hobbes, 1588-1679Slide23

John Locke, 1632-1704Slide24

John Locke

Father

of Classical Liberalism (civil liberties, economic freedom, limited government)

Along

with Descartes, most important 17

th Century Western philosopher.Worked in Boyle’s lab.Slide25

Corpuscularianism

The view was that everything is made out of corpuscles– microscopic little bits that had a certain shape, size, and momentum. Slide26

Corpuscularianism

However

, the corpuscles did not have

color, taste, smell, sound, or warmth

. These other qualities were explained as the effects of the corpuscles on our sensory organs.

For example, heat is just the motion of corpuscles, but this motion causes us to experience the sensation of warmth.Slide27

The Unreality of Tastes, Colors, etc.

“I

think that tastes, odors, colors, and so on are no more than mere names so far as the object in which we place them is concerned, and that they

reside only in

the

consciousness. Hence if the living creature were removed, all these qualities would be wiped away and

annihilated” (Galileo,

The Assayer

). Slide28

Galileo, The Assayer

“I think that tastes, odors, colors, and so on are no more than mere names so far as the object in which we place them is concerned, and that they

reside only in the consciousness

.

Hence if the living creature were removed, all these qualities would be wiped away and annihilated” Slide29

Problems for the Conformal Theory

But

if colors, for example, exist only in the mind, then it cannot be true that when I represent a white horse, my soul has the same form as a white horse.

There are no white horses

. There are horses that cause me to experience whiteness when light bounces off of them. But the whiteness itself depends on me, the observer. Whiteness exists only in minds.Slide30

The Idea TheorySlide31
Slide32

Macbeth, Act I, scene

i

Is this a dagger which I see before me,

The

handle toward my hand?

Come, let me clutch thee. I have thee not, and yet I see thee still.

Art

thou not, fatal vision, sensible

To

feeling as to sight? or art thou but

A

dagger of the mind, a false creation,

Proceeding

from the heat-oppressed brain?Slide33

Hallucinations

Normally

we talk as though we see physical things, out there in the world. “I see a dagger”– a dagger is obviously not mental. But what do I

see

when I hallucinate a dagger?Slide34

Ideas

A popular view among 17

th

and 18

th

Century Western philosophers was that what you really saw was ideas– mental things.On this view, ideas were something like little colored pictures in the mind.Slide35

Idea Theory

Mind

Idea of a Dagger

DaggerSlide36

Hallucination

Mind

Idea of a Dagger

No DaggerSlide37

Indirect Realism

Views

of this general form are called “indirect realism.” What you

directly

see are mental entities (for example, ideas). You only

indirectly see the real things that the ideas represent.Indirect realism allows us to maintain that there’s an appearance-gap between what we see (ideas) and the things that the ideas represent.Slide38

Resemblance Theory

According to the resemblance theory of representation, ideas represent things by resembling them– sort of like how painting works.Slide39

PaintingSlide40

The Nature of Ideas

According

to Locke, ideas are “the pictures drawn in our minds”

(

Essay, II.x.5). Slide41

The Nature of Ideas

An

idea of a horse, then, is very much like a picture, image, or painting of a horse.

Compare

Hume: “By ideas I mean the faint images of [perceptions] in thinking and reasoning” (Treatise, I.i.1).Slide42

Mind

Idea of a Dagger

Dagger

Resembles

SeesSlide43

Resemblance

This means that even though what you see are ideas, the ideas are

close copies

of the real things, the way a realistic painting is a close copy of a scene.Slide44

Corpuscularianism Revisited

So how do we handle the fact that the world isn’t colored?Slide45

Mind

Idea of a Dog

Dog

Partly Resembles

SeesSlide46

Note

This was already really part of the original resemblance theory… nobody thinks your idea of a dog

smells

like a dog!Slide47

Terminology

Locke called properties like shape, size, and motion– properties that both ideas and real things could have–

primary qualities

.

Other properties that only ideas had were called

secondary qualities.Slide48

Locke on Language

“Words are sensible signs, necessary for communication of ideas. Man, though he have great variety of thoughts, and such from which others as well as himself might receive profit and

delight…”Slide49

Locke on Language

“yet they are all within his own breast, invisible and hidden from others, nor can of themselves be made to appear…”Slide50

Locke on Language

“The comfort and advantage of society not being to be had without communication of thoughts, it was necessary that man should find out some external sensible signs, whereof those invisible ideas, which his thoughts are made up of, might be made known to others.”Slide51

Problems #1: Abstract IdeasSlide52

George Berkeley (1685-1753)Slide53

Locke on General Terms

“

It is not enough for the perfection of language, that sounds can be made signs of ideas, unless those signs can be so made use of as to comprehend several particular

things…”Slide54

Locke on General Terms

“…for

the multiplication of words would have perplexed their use, had every particular thing need of a distinct name to be signified

by…”Slide55

Locke on General Terms

“To

remedy this inconvenience, language had yet a further improvement in the use of

general terms

, whereby one word was made to mark a multitude of particular existences.”Slide56

Particular Terms

LockeSlide57

General Terms

DogSlide58

Abstract Ideas

If

we accept the idea theory, then, we have to accept that there are “abstract ideas”– not mental pictures of a particular person, but mental pictures that resemble equally a group of things.

These abstract ideas are the meanings of general terms.Slide59

Berkeley vs. Abstract Ideas

Berkeley, however, argues that abstract ideas are impossible.

The

abstract idea of a man is supposed to apply equally to a tall man and a short man; a black man and a white man; a skinny man and a fat man; well-dressed man and a pauper, etc.

But

no picture resembles equally all such men, as any picture of a man depicts him as either skinny or fat, but not both and not neither. Slide60

Problem #2: The Determinacy of ThoughtSlide61
Slide62

Wittgenstein’s Man on the Hill

“

A picture which corresponds to a man walking up a hill forward corresponds equally, and in the same way, to a man sliding down the hill backward.”

--

Philosophical InvestigationsSlide63

Wittgenstein’s Man on the Hill

“Perhaps a Martian would describe the picture [as the man sliding down]. I do not need to explain why

we

do not describe it so.”

Representation can be

more determinate than resemblance.Slide64
Slide65
Slide66

Seeing vs. Seeing-as

What the Necker cube example suggests is a more general problem.

You

can look at the Fischer cow and not see that it is a cow. When you see the picture

as

a cow, your perception changes. But if your idea of the picture is just a copy of that picture in your head, what about it changes such that once it was just squiggles and then it’s a cow?Slide67

Problem #3: ErrorSlide68

Representation and Error

On the Idea Theorist’s view, I can only represent a thing if I have a mental image that sufficiently resembles it.

But there seem to be lots of things that we can think about, while being massively in error about.Slide69

Advertisements vs. RealitySlide70
Slide71

Problem #4: The Structure of ResemblanceSlide72

Equivalence RelationsSlide73

Resemblance as an Equivalence Relation

Resemblance, like identity, is an equivalence relation, meaning it’s reflexive, symmetric, and transitive:

Reflexive

: for all X, X resembles X. (Everything resembles itself.)

Symmetric

: for all X and Y, if X resembles Y, then Y resembles X. Transitive: for all X, Y, and Z, if X resembles Y and Y resembles Z, then X resembles Z.Slide74

Problem for the idea theory: resemblance is an equivalence relation, but representation is not. Therefore representation ≠ resemblance.Slide75

1. Representation is Not Reflexive

You can have a representation that represents itself (for example, a map that includes the map’s location), but most representations don’t represent themselves.

You can have a painting of a horse, that is not a painting of a painting of a horse (not a painting of itself).Slide76

2. Representation is Not Symmetric

Most

of what gets represented is not representational. My thoughts represent lakes and rivers and trees, but lakes and rivers and trees don’t represent my thoughts.

And even when I do represent representations (when I think about a painting, say), usually they don’t represent me or my thoughts.Slide77

3. Representation is not Transitive

The directory at the museum might represent the location of a certain Picasso painting. That painting could represent a horse. But the directory doesn’t represent any horses, it only represents paintings.Slide78

Problem #5: Truth-EvaluabilitySlide79

Concepts

Concepts are representations of things or qualities: so I can have a concept of Obama, or a concept of red, or a concept of a horse, or a concept of a concept.

Importantly, concepts are

not truth-evaluable

. My concept of red isn’t true, and it isn’t false either. It might be more or less accurate.Slide80

Propositions

We can say that when I

think of

a thing, or

think about

a thing, then I am entertaining a concept. However, when I think that such-and-such, I am entertaining a proposition. Slide81

Propositions

For example, I can think that Obama is the US president, or think that grass is red, or think that the concept of a horse is not a concept.

Propositions

are

truth-evaluable: when I think that grass is red, my thought is false. (Not so when I just think

of red.)Slide82

The idea theory seems to have trouble distinguishing concepts and propositions.

According to the idea theory, thought is having ideas, and ideas are like mental pictures. Are mental pictures truth-evaluable? If they are, then concepts aren’t ideas. If they aren’t, then propositions aren’t ideas.