Chaffee, 3e Chapter 5.pptx

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Knowledge of the Good

Socrates claimed that the virtuous person is one who knows the Good

It is then of the utmost importance to figure out how one can actually know the Good This is the project that Plato takes up His goal is to try and show how knowledge of the

Good is possible But in order to answer that he must first answer

the more general question: how do we know anything?


What is Knowledge?

I parked my car in the lot, do I know where my car is?

Knowledge requires certainty Object of knowledge can’t change

If what can be known can’t change, then physical world can’t be an object of knowledge It is in a constant state of flux (becoming)


What is Knowledge? II

So, if we are to have real knowledge it must meet the following requirements Unchanging Non-physical eternal

Plato’s strategy is to look for an area where there is some knowledge already and then try to figure out what is going on there Geometry/mathematics


Theory of the Forms

So, numbers and geometrical shapes exists as non-physical, eternal, and unchanging objects that are the objects of knowledge

We get in touch with these objects via the use of reason Plato is a rationalist Knowledge can only be achieved via the use of

reason These non-physical objects are called Forms


Theory of the Forms II From the Greek ‘eidos’

Means idea, but not in the way that we use the word These Ideas exist outside of the mind, outside of time

and space The mind is able to ‘grasp’ these forms

Two more arguments for Forms Degrees of perfection One over Many


Degrees of Perfection


Degrees of Perfection II

How do you know that the triangles are not perfect unless you know what the perfect one is like And you are able to compare

This, says Plato, is true of everything You know that some actions are not perfectly

just But how could you know this unless there was

Perfect Justice and you knew it? That is the Form of Justice


Those are trees

The Form of Tree


One Over Many

The Forms explain why it is that we categorize certain objects as male but not others There is a Form for every thing that objects have in

common The objects must all have something in common, or

why else would we put them in a group together? But they don’t have anything physically in common

When you see that an object is, say, a desk you are grasping the Form of that object

The objects are said to ‘participate’ in the Form An object can participate is many Forms at the

same time


The Divided Line

Metaphysics Epistemology

Images

Intelligible World

Visible World

Knowledge

OpinionImagination

Sensible Objects Perception

Lower Forms Reasoning

Higher Forms

Understanding

The Good


The Allegory of the Cave


READING CRITICALLYAnalyzing Plato’s Allegory of the Cave (1)

In Plato’s allegory, discarding ignorant beliefs and embracing the truth can be a disturbing process, as we are forced to see things objectively, illuminated as they really are, rather than shrouded in the shadows of bias and distortion. Describe an experience in which achieving a knowledgeable, truthful insight was a disturbing experience for you.


READING CRITICALLYAnalyzing Plato’s Allegory of the Cave (2)

Plato believes that the view of knowledge embodied in the Allegory of the Cave has profound and far-reaching implications for education:

Education then is the art of doing this very thing, this turning around, the knowledge of how the soul can most easily and effectively be turned around; it is not the art of putting the capacity of sight into the soul; the soul possesses that already but it is not turned the right way or looking where it should. This is what education has to deal with.

Explain what you believe Plato means by these two contrasting ideas of education. Describe two examples from your own educational experience, one which involved “turning your whole soul toward reality” and another in which you attempted to “put the capacity for sight into your soul.”

Evaluating your life as a whole, at what stage in Plato’s allegory would you place yourself? Why?


Aristotle

Lives 384-322 BCE (Socrates dies in 399)

Is the first to realize that we need some criterion for determining when an argument is good or bad

Discovers deductive logic Deductive arguments are contrasted with

inductive argument


The Job of Philosophy

For Aristotle philosophy is divided into two parts Theoretical– aims at knowledge Practical– aims at some action

Natural philosophy is a theoretical science The goal is to start with particular things and

discern their essential characteristics, which we then use as the first premise in a syllogism


The Method of Science/Philosophy

Opinions

Dialectic

Principles

Demonstrations

Conclusions


Explanation

What we want are explanations An explanation does not merely tell us THAT

something is the case It tells us why it MUST be the case

To really understand something we must be able to give the reason why it has to be the way that it is These explanation take the form of valid

syllogisms An argument with two premises and a conclusion


Explanation II

Say I wanted to explain why copper conducts electricity Well, copper is a metal And all metals conduct electricity

We can put this as follows All metals conduct electricity Copper is a metal So copper conducts electricity

Now I understand why copper has to behave the way it does


First Principles

The first principles of a science are known directly by reason in a way that does not need any further proof Exactly like geometry: that the shortest distance

between two points is a straight line is self-evident

For instance what Aristotle calls ‘the law of non-contradiction’ Nothing can be both true and false at the same time

Does not need any evidence or support other than itself Once one understands the words one just come to see,

with reason, that it HAS TO BE true


Necessary

The law of non-contradiction is supposed to be a necessary truth about reality It is impossible for it to be false

This law has two interpretations A metaphysical interpretation And a Logical interpretation

As a metaphysical principle it says that opposite properties cannot simultaneously exist in the same object As a logical principle it says that no sentence is both

true and false at the same time


Reductio ad Absurdum

Accordingly to show that some claim results in a contradiction is to show that it cannot possibly be true

This, together with another basic principle of logic The law of the excluded middle Every sentence is either true or false; there is no third

alternative

Gives us a powerful way to argue to show that something is true we by assume that it is

false and showing that it leads to a contradiction So the original assumption must be false


Plato’s version

Plato tries to give an explanation This thing is a human being because it

participates in the Form Human Being The Form is eternal, perfect and unchanging It is the essence of what it means to be a human

being It is the perfect human being

Aristotle focus on ‘participation’


Visible worldphysical

FiniteConstantly changing

Intelligible WorldNon-physical

Eternalunchanging

The Form of Human Being

Participation


The Third Man Argument

The Form is supposed to explain why it is that we call some things by the same name,

But the name must also apply to the Form itself It is the thing that all instances of the Form have in

common But now we have a new group, all of the objects

and the Form They must have something in common, and so

on…. This generate what Aristotle called an infinite regress Since there is no end to the regress we never get an

explanation for why humans differ from (say) dogs We are simply told that they resemble something that

resembles something that resembles something….


Aristotle

So he rejects Plato’s metaphysics and ontology He also rejects atomism

The idea of void is contradictory as it implies that what does not exist exists

If it were true the world would not be explainable We would not be able to say why the stuff

around us MUST be the way that it is since according to atomism everything is the result of chance

For Aristotle, the world is ordered & law governed


Starting Over

Aristotle agrees that we want knowledge of essences He has a theory of forms, but his forms are in

the objects around us All objects are composed of two parts

Form Matter

These two things are separable in thought but not in reality Aristotle thinks that each red object has (the

very same) form (of redness) It is simultaneously located at different locations


Starting Over II

For each red object we can separate the redness (the form of red) from the material But this is an ability that the mind has Plato’s mistake was to think that these forms existed

apart from the objects they are located in

But still, the form of red is real It exists as part of the object

This becomes part of his response to Parmenides He is going to argue that change consists in material

coming to have a form that it did not have before


The Reason(s) Why

Remember from before that to really know something Aristotle thinks that we must be able to Explain why the thing has to be the way that it is

and cannot be any other way

That is, we need to be able to give the reasons why the change happened The word Aristotle uses, ‘aitia’, is translated as

‘cause’ But he really means reasons that explain why the

thing happened the way that it did Or is the way that it is


The Sculpture

So, consider some sculpture of Socrates What are the reasons that this particular sculpture is the way that

it is?

The sculpture is the result of a process and has four causes each which partially explain why it is the way it is Part of the answer is that it is made from a certain

material If it were made from spaghetti it would be very

different Part of the answer is that it has a certain shape It resembles Socrates Part of the answer is that someone sculpted it


ARISTOTLE’S FOUR CAUSES

Material cause: the “matter” of which a thing is made.

Formal cause: the embedded form that gives shape and purpose to the “matter.”

Efficient Cause: the “triggering” action that sets the thing in motion.

Final Cause: the ultimate purpose for which a thing exists.


The 4 Causes

Material The thing that is the same before and after the

change Formal

The thing that is different before and after the change

Efficient The thing that does the changing

Final ‘that for the sake of which’ the change is done


Change

To give an explanation of a change we need to specify all of these causes

Examples 1. Sculpture

Material-stuff being sculpted (say, Marble) Formal-shape sculptor intends to make Efficient-the artist doing the sculpting To get a statue with a certain shape


4 Causes II

2. Heating a pan Material-THE PAN! Formal-heat Efficient-fire (or something hot) Final- to get a hot pan

When the pan is (actually) cold it is potentially hot This means that the material, the pan, is able to

receive the form of heat So, the pan is not potentially an eagle


4 Causes III

In order to become actually hot the pan needs to come into contact with something that is itself already actually hot In his terminology, this thing must already

posses the form of heat This thing then transmits, or transfers the form

to the material, thereby causing the pan to become actually hot

So, in a sense the cold and hot do exist in the same object; one is actual one is potential


READING CRITICALLYAnalyzing Aristotle’s Concept of Reality (1)

Plato believes that Forms occupy the highest level of reality in the eternal realm of Being. Thus, the perfect Idea of “horse” is the most real element in his metaphysic, the actual horse the least real. Aristotle inverts this hierarchy of reality: the individual horse is the most real element in his metaphysic, whereas the abstract concept of “horse” the least real. Explain which view you find to be most intelligible and the reasons why.

Aristotle criticized Plato’s concept of “participation,” calling it “a mere empty phrase and a poetic metaphor.” Do you agree with his critique? How do you think Plato would defend himself?


READING CRITICALLYAnalyzing Aristotle’s Concept of Reality (2)

Plato believed that the human soul is immortal, existing before birth and continuing after death. Aristotle believed that the soul is a natural phenomenon that gives form and purpose to the body, but ceases to exist after the body dies. Which view of the soul do you find most compelling? Why?

Aristotle believed that the entire universe is purposeful, both individually and collectively. Do you agree with this contention? Explain why or why not and provide an example to support your perspective.

Although Aristotle does not believe in a supernatural Creator or God, he does conclude that there must be a “first (Final) cause,” a “prime mover,” “pure thought, thinking thought.” Evaluate the cogency of Aristotle’s idea and the reasoning he uses to reach this conclusion.


RENÉ DESCARTESHow do You Know Whether or Not You are Dreaming?


The Rejection of Aristotle

Galileo– 1564-1642 CE Descartes 1596-1650 Newton-- 1643-1727 At this time in history the dominant philosophy

would have been a Christianized version of Aristotle’s philosophy and physics

But recent empirical work suggested otherwise Invention of telescope


The Rejection of Aristotle II

Heliocentric view of the universe Galileo times objects as they roll down hill and

discovers that they all accelerate at the same rate

This is the beginning of the Empiricist movement John Locke 1632-1704 George Berkeley 1685-1753 David Hume 1711-1776


Descartes

But Descartes is still a Rationalist He is very critical of Aristotle’s views (but is

also in some ways still in the Aristotelian tradition)

He is a champion of what is called ‘mechanistic philosophy’ The world is a giant machine Objects do not move themselves He accuses Aristotle of putting mind into nature


Descartes II

His goal is to find a foundation on which all other knowledge can be built

He agrees with Plato that knowledge requires certainty

But rejects Plato’s idea that the physical world is not knowable


Certainty

But what does it mean to be certain? It is being unable to doubt Something that cannot possibly be doubted is

certain So, his strategy is to adopt the Method of

Doubt (MoD) This method instructs us to take our beliefs and

subject them to doubt If it is possible to doubt them we treat them as

false


MoD

This does not mean that he thinks that they are actually false

The point is that we treat them as false until we find a foundation which is indubitable And then we build up everything on top of that

By ‘possible to doubt’ he means any possibility what so ever We are to try and think of the most far-fetched,

wacky, way out scenarios we can come up with


MoD II

This will guarantee that whatever can’t be doubted really is certain

If we could find something that was truly indubitable in this sense we could use it in a valid argument (like a syllogism)

The conclusion of which would be that the world exists in the way that we think it does Or in other words, that we could have knowledge

of the physical world


Step One: Doubting the Senses

Descartes begins by pointing out that our senses are unreliable Straight things look bent Round things look oval Square things look round Mountains look purple The Sun looks small, etc.

So, we can doubt that what our senses tell us is accurate and so they cannot be the foundation


Which Line is Longer?


They Are the Same Length!


Step Two: Doubting the Physical World

But, you might think, though it may be the case that the senses are unreliable,

We must be able to trust them generally, right? Surely I can’t doubt that there is a table here in

this room, can I? Yes I can

I have seen tables in my dreams, I could be dreaming now How can I rule this out?


Step Two II

I can’t rule it out Anything I would cite as evidence would be

something that would also be true in the dream So, if I say ‘I see the table, I hear it, I feel it’ or

whatever, that is, if I cite my experience of the table as evidence,

It would look, sound, etc, exactly the same in my dream

Except in my dream there is no table at all, just my experience ‘as of a table’


Step Two III

Descartes takes this to the extreme by imagining that there is an Evil Genius Someone who has the powers of God But who is not good

This evil genius is determined to deceive you into thinking that there is a physical world when there isn’t one Akin to the matrix The Machines are the evil geniuses


Step Two III

Except in Descartes’ version there is no ‘outside’ the matrix Everything would seem to you just like it does

right now but none of it would be real He does not actually believe that this is true His point is that we cannot use this as the

foundation of our knowledge because there is this (albeit small) possibility that we can’t rule out


Step Three: Doubting Mathematics

But surely 1+1=2 must be certain! Whether there is really a physical world or not

the mathematical truths should be true This is where Plato looked for certainty Descartes thinks that he can imagine a scenario

in which 1+1 does not equal 2 We are all familiar with making mistakes in

mathematics


Step Three II

You do some problem, get some answer that seems to be absolutely correct Only to find out that the answer is wrong

In fact we also are familiar with doing the problem, getting an answer, checking your work, getting the same answer Only to find out that the answer is wrong Because we are making the same mistake, but

not noticing it


Step Three III

So, couldn’t it be possible that in reality 1+1=3 (say, the point is that it is something other than 2) and the evil genius is tricking me into thinking

that 1+1=2 is true By hiding some mistake from me every time I

count or do mathematics


1+1=(step)3 1.) Let x=1 2.) Then x2=x (i.e. one squared is one) 3.) Now let’s subtract 1 from each side

Then (x2-1)=(x-1) 4.) Now let’s factor the left hand side

Then (x-1)(x+1)=(x-1) 5.) Now let’s divide each side by (x-1)

Then (x+1)=1 6.) Let’s add 1 to each side

Then (x+2)=2 7.) But since x=1 we have 3=2

Another way to write ‘2’ is ‘1+1’, so we have 1+1=3


Review

Descartes developed a method designed to deliver certainty

The Method of Doubt For the purposes of the method, if we can doubt

a belief then we treat that belief as false He doubts that the world is the way that it

appears That there is a physical world at all And finally the mathematical truths


Cogito ergo Sum

However, the one thing that he cannot doubt Is that while he is doubting he must exist

Even if there were and Evil Genius and Even if he were deceiving me into thinking that

there was a physical world when there in fact wasn’t one

It couldn’t be the case that I think that there is a physical world if there weren’t a me to be deceived

So when I am thinking I know I exist, this can’t be doubted


The Foundation

So now he has discovered something certain He exists as a thinking thing Whether there is a physical world or not he

cannot doubt that he exists This is the foundation on which he plans to

build back all of the stuff he previously doubted

He then notices that this piece of knowledge has a certain quality that he calls being ‘clear and distinct’


Clear and Distinct Ideas

An idea is clear if it is ‘manifest to an attentive mind’ If you were awake and attentive, well fed, not

distracted, etc, you would see that it is true An idea is distinct if it ‘contains nothing but

things which are themselves clear’ Descartes concludes that the truth that he has

discovered, ‘I think therefore I am’ is clear and distinct because it is a self-evident truth


The Road Back

He then concludes that all clear and distinct ideas are true These ideas are self-evident necessary truths Their truth is apprehended by ‘rational intuition’ This is, of course, the way in which he is still in

the Aristotelian tradition He now has a foundation and a way to verify

his results


The Next Step

His next step is to see how he can extend what he has got so far

He knows that he exists and that his essential characteristic is thinking It is possible that he exist without a body But not possible that he exist without thinking By thinking he means any form of mental

activity Include feeling pain, seeing blue, etc Phantom Limb pain


The Wax Argument

Take this piece of wax, it has certain physical properties It has a taste A smell Makes a sound A certain shape And hardness

But take this wax and hold it next to a fire and all of those physical properties change


The Wax Argument II

It no longer has the same shape, smell, size, taste, feel, etc Everyone of its physical properties change

But we know that it is the same wax throughout this process It is the same wax before and after the melting

How do we know this? Not via the senses but via rational intuition


The Wax Argument III

What we have is some appearances The wax looks a certain way

On the basis of these appearances we make a judgment that there is a physical object out there But, strictly speaking, we do not have any

contact with the object We perceive the real nature of the wax solely

with our mind


Descartes’ Philosophy of Mind

The mind is a distinct, non-physical entity whose essential characteristic is thinking The Evil Genius Argument; it is possible that I

exist without a body– this is clear and distinct so true

Physical objects never think Their essential characteristic is ‘extension’

(taking up space) and are purely mechanical The Wax argument; the real nature of the wax is

grasped by the mind as a substance which can change shape


Descartes’ Philosophy of Mind II

So what YOU are, really, is an immaterial mind What you interact with are ideas (your

experiences), which are mental (i.e. non-physical),

The procession of these ideas makes up your mental life, which you have immediate and unfailing access to

The question then is, Does my experience accurately represent

reality?


The Common Sense Picture


Descartes’ Picture

Causation

Judgment

Causation


The Evil Genius

Causation

Judgment

Causation

?


An Analogy

Imagine that you have been raise in a room where you are never allowed to leave

In this room you have a television monitor that shows you scenes out on Van Damn St.

Based on these images you conclude that there are people out there doing various things

But how do you know that the camera really is out on Van Damn St.?


An Analogy II

It might be the case that someone wants us to think that there are people out there who are doing various things,

But in reality it is all just a Hollywood set designed to fool us

We cannot leave the room and go outside to check, so how do we know?

Descartes argues that God exists and wouldn’t deceive us so we can trust the way things appear


The Evil Genius

Causation

Judgment?


Mission Accomplished

Since God exists, and He is not a deceiver I can have knowledge of the physical world But this knowledge consists in the innate a priori

clear and distinct truths (math, geometry, physics, logic, philosophy)

Information obtained via the senses is ‘obscure and confused’ Real knowledge is achieved by rational intuition


READING CRITICALLYAnalyzing Descartes’ Radical Doubt (1)

Have you ever had the experience of wondering whether much of what you had been brought up to believe as true was in face unreliable? If so, identify some of the main beliefs or values that you called into question. Was there a particular event that stimulated the process of doubt and examination? What was the outcome of your reflective questioning?


READING CRITICALLYAnalyzing Descartes’ Radical Doubt (2)

Try to replicate Descartes’ reflective process. Describe your current situation as you are reading this text, just as he does. Then try to trace the pattern of thinking: Can you imagine that what you think is real is actually a dream? How can you be sure? Haven’t you had dreams that were at least as realistic as the current situation in which you find yourself? Is there any clear criteria you can use to differentiate between when you are dreaming and when you are awake?

Try to replicate Descartes’ foundational starting point, “I think, therefore I am.” Does your ability to think convince you, for once and for all, that you exist? What does it mean for you to say, “I exist”? Exactly how would you describe the “I” that exists?


CRITERIA FOR JUSTIFICATION OF BELIEFS

To what extent is the belief supported by sound reasons and compelling evidence derived from reliable sources?

How effectively does the belief explain what is taking place?

To what extent is the belief consistent with other beliefs you have about the world?

How effectively does your belief help you predict what will happen in the future?

Is the belief falsifiable?

Chaffee, 3e Chapter 5.pptx

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