Transcript SCIENCE and the REALLY REAL Can tell us the

SCIENCE and
the REALLY REAL
Can Science tell us the
Truth about the Real?
• What makes a theory scientific?
• What is the difference between
superstition, belief,
.
and science?
• What is the place of science in human life?
• Can something come from nothing?
• What are ideas “made of”?
• Can I trust what I see to be real?
• How can know what I belief is true?
• How can I prove (to others) what I know to be true
really is true?
• Why do we trust science sometimes and reject it at
other times?
• Does “scientific objectivity” mean we must present
all sides of the issue (as the media must)?
Philosophy of Science
Philosophy of Science is similar to Epistemology
because of its concern with the role of science
generating TRUE statements that constitute
knowledge about ourselves and the world in
which we live.
All sciences (physics, biology, psychology, and
so on) share certain assumptions about the
production of knowledge and the methodology
used in theory formation, the nature of
hypotheses, observation, experiment,
verification and falsification, and the nature of
explanation.
We live in an age the puts a great deal of trust
. truth and nothing but
in science to tell us “the
the truth.”
Many of our decisions, both private and public,
are based on scientific information.
But many people also distrust science and are
uncertain about the reliability of scientific
theory and whether the technological
marvels of science are ultimately capable of
making our lives better (since we might find
in the future that they are ultimately making it
worse).
. studying the
Some people believe that
philosophy of science is useless to their daily
concerns, but it is not.
We face a host of public debates, from global
warming to genetic engineering, in which
science often plays a crucial role.
When need to be better informed when we
make difficult judgments concerning public
policies that have a significant impact on our
own lives as well as the future of our children.
What exactly is Science?
The word “science” comes from the Latin word
scio, which mean “to know”
What is the difference between common-sense
“knowing” and science?
You’re probably thinking…Science explains
things. It answers the “why” and “how”
questions about natural events. It explains
what causes what.
In good philosophical fashion, however, we must
ask, “What is an explanation?”
.
Many (but not all) philosophers of science
subscribe to the deductive-nomological
model (also called the covering law model)
of explanation. {“nomous” = law}
According to this model, and explanation of an
event consists in “covering” or “subsuming”
the event under some law.
In other words, explaining something requires
that a description of it is deducible from the
relevant laws of nature.
.
One might explain, for
example, the expansion
of some liquid or gas by
appealing to some law
such as “gas expands
when heated.”
But one can still ask, Why
does heat cause gas to
expand?
So science is .concerned with the laws
of nature, and it is here that science
seems to go beyond common-sense.
Scientists discover and formulate (but can not
create) nature laws.
The concept of law is important in science
because it make predictions possible, and
predictions make control possible.
If I can predict exactly how much my hotdog will
expand because I understand that gases
expand when heated, I can determine the size
of the bun I will need.
.
The Philosopher of Science also must be able to
give some account of how scientific
conclusions can be validated.
How do we know that we have arrived at a
scientific truth?
It is significantly different than how we have
arrived at a common-sense truth?
Karl Popper
…took issue with the notion that scientific
progress consists in extending the laws of
nature to explain more and more hitherto
unexplained events.
Although he didn’t reject the deductivenomological model, he did try to refocus the
attention of philosophers of science on issues
surrounding the testability of what he liked to
call “conjectures.”
He thought that science grows not so much by
deducing hypotheses .from some known laws
as it does by making interesting guesses and
then subjecting those guesses to rigorous
criticism.
It is more fruitful, Popper maintained, to try to
disprove or falsify a conjecture than to verify or
confirm it.
We can verify that crows are black by observing
many crows, but that does not mean that the
next crow we see will be black or that all crows
are black.
Attempts to falsify theories make a greater
contribution to the growth of science than
attempts to verify them.
If we could prove that there were no white crows,
we would know with certainty that the next crow
we saw would be black.
Popper’s First Thesis
“Within the field of science we
have a criterion of
progress: even before a
theory has ever undergone
an empirical test we may be
able to say whether,
provided it passes certain
specified tests, it would be
an improvement on other
theories which we are
acquainted.”
This criterion of relative potential
.
satisfactoriness in a preferable
theory is
satisfied…
-if the theory has a greater amount of empirical
information (or content) than rivaling theories,
-if it is logically stronger,
-if it has the greater explanatory and predictive
powers,
-if it can be therefore more strictly and severely
tested by comparing the facts with
observation.
In short, we prefer an interesting, daring, and
highly informative theory to a trivial one.
Popper’s positive comments on Einstein’s theory…
.
The problem with verification theories was precisely this fact—that they always fitted,
that they were always confirmed—which in the eyes of their admirers constituted
the strongest argument in favor of these theories. It began to dawn on me that this
apparent strength was in fact their weakness.
With Einstein's theory the situation was strikingly different. Take one typical instance —
Einstein's prediction, just then confirmed by the finding of Eddington's expedition.
Einstein's gravitational theory had led to the result that light must be attracted by
heavy bodies (such as the sun), precisely as material bodies were attracted. As a
consequence it could be calculated that light from a distant fixed star whose
apparent position was close to the sun would reach the earth from such a direction
that the star would seem to be slightly shifted away from the sun; or, in other words,
that stars close to the sun would look as if they had moved a little away from the
sun, and from one another. This is a thing which cannot normally be observed since
such stars are rendered invisible in daytime by the sun's overwhelming brightness;
but during an eclipse it is possible to take photographs of them. If the same
constellation is photographed at night one can measure the distance on the two
photographs, and check the predicted effect.
Now the impressive thing about this case is the risk involved in a prediction of this kind.
If observation shows that the predicted effect is definitely absent, then the theory is
simply refuted. The theory is incompatible with certain possible results of
observation—in fact with results which everybody before Einstein would have
expected. This is quite different from the situation I have previously described,
when it turned out that the theories in question were compatible with the most
divergent human behavior, so that it was practically impossible to describe any
human behavior that might not be claimed to be a verification of these theories.
Popper’s Rules
1. It is easy to obtain confirmations, or verifications, for nearly
every theory — if we look for confirmations.
2. Confirmations should count only if they are the result of
risky predictions; that is to say, if, unenlightened by the
theory in question, we should have expected an event
which was incompatible with the theory — an event which
would have refuted the theory.
3. Every "good" scientific theory is a prohibition: it forbids
certain things to happen. The more a theory forbids, the
better it is.
4. A theory which is not refutable by any conceivable event is
non-scientific. Irrefutability is not a virtue of a theory (as
people often think) but a vice.
5. Every genuine test of a theory is an attempt to falsify it, or to
refute it. Testability is falsifiability; but there are degrees of
testability: some theories are more testable, more exposed
to refutation, than others; they take, as it were, greater
risks.
6. Confirming evidence should not count except when it is the
result of a genuine test of the theory; and this means that
it can be presented as a serious but unsuccessful attempt
to falsify the theory. (I now speak in such cases of
"corroborating evidence.")
7. Some genuinely testable theories, when found to be false,
are still upheld by their admirers — for example by
introducing ad hoc some auxiliary assumption, or by
reinterpreting the theory ad hoc in such a way that it
escapes refutation. Such a procedure is always possible,
but it rescues the theory from refutation only at the price of
destroying, or at least lowering, its scientific status. (I later
described such a rescuing operation as a "conventionalist
twist" or a "conventionalist stratagem.")
.
Popper disagrees with
Verificationists
Verificationists hold that whatever cannot be
supported by positive reasons is unworthy of
being believed, or even of being taken into
serious consideration.
It must be verified by positive evidence, shown
to be true, or at least highly probable.
They demand that we should accept belief only
if it can be verified or probabilistically
confirmed.
Popper agrees with
Falsificationists
Falsificationists hold that what can in principle
be overthrown by criticism is unworthy of
being considered.
If it cannot be made possibly false, then it is
worthy of consideration.
Since we can never give positive reasons which
justify why a theory is true, it is more profitable
to prove that they cannot be made false.
Truth is not the aim of science
We also want to stress that truth is not the aim
of science. We want more than mere truth:
what we look for is interesting truth – truth
which is hard to come by.
And in the natural sciences, what we look for is
truth which has a high degree of explanatory
power, which implies that it is logically
improbable.
Mere truth is not enough; what we look for are
answers to our problems.
When a judge tells a witness that he should speak “The
truth, the whole truth, and
. nothing but the truth,” what
his looking for is as much of the relevant truth as the
witness may be able to offer.
A witness who likes to wander off into irrelevancies is
unsatisfactory as a witness, and thus part of “the
whole truth.”
It is quite obvious that what the judge – or anybody
else – wants when he asks for “the whole truth” is as
much interesting and relevant true information as
can be got; and many perfectly candid witnesses
have failed to disclose some important information
simply because they were unaware of its relevance
to the case (and yet continued to ramble on about
irrelevant and yet truthful details).
.
“Interests” or “relevance,” in the sense intended
here, can be objectively analyzed; it is relative
to our problems; and it depends on the
explanatory power, and thus on the content or
improbability of the information.
1. A theory should proceed from some simple,
new, and powerful, unifying
idea about some
.
connection or relation (such as gravitational
attraction) between hitherto unconnected
things (such as planets and apples) or facts.
This is the requirement of simplicity.
2. The new theory should be independently
testable; it must lead to the prediction of
phenomena which have not so far been
observed.
3. It should be able to pass new and severe
tests which have not been part of the testing
process thus far. This is necessary in order
for science to be able to progress and grow.
POPPER’S MAIN POINT:
.
Theories and “facts” we can presently prove using the
methods we have previously used that verify as
true what can be currently observed do not lead to
new information (plus, they are basically boring).
Science only progresses when we make conjectures
about things we don’t already know and yet are
predictably possible simply because it is impossible
to prove that they are false. In other words, we
learn much more by trying to prove something is
potentially false than by verifying that it is already
true.
What if your conjecture
can
not
.
be predicted to be possibly
false (as Popper would like),
but then neither can it be
verified to be true, since there
is no possible way to confirm
it empirically?
And, yet, you are still certain
that it MUST be true?
Daoism
The word Dao means “road” or
“path” or “Way” in Chinese.
The Dao de Jing (written by Lao
Tzu in the 5th cent. BCE) is
often described as “the Book
of the Way and its Power.”
The book is written in a poetic
and cryptic style, and it is as
much about ethics as it is
about knowing the “truth”
about the “real.”
ONTOLOGY – the study of “being”
1. For something to be real, it must exist.
Right?
2. For something to exist, it must be identifiable
and different from other things. Right?
3. For something to exist, it must be permanent
(for as long as it exists). Right?
4. For something to exist, it must have
substance. Right?
Well, maybe not (according to the Dao & Plato).
DEFINITIONS….
.
Aristotle began with the notion that you state
what a thing IS, not “what it is not,” when
providing a good explanation.
Hegel said that any explanation of what a thing
IS includes also “what it is not.” For example
you know that a chair IS a chair because you
are also immediately aware that it is NOT a
table.
What the Dao IS cannot be described, so it must
be discussed only in terms of “what it is not.”
The Dao or the “really real” according to the
. it is not independent
Dao de Jing exists, but
or identifiable from everything else, because
everything that is real is interrelated.
It is an ever-flowing, always changing reality
which is all things and yet no specific thing in
itself.
It is not matter, and yet all matter is part of it.
It is not “being” since “non-being” is equally a
part of it.
Both the existent and the non-existent can be
classified as the “real.”
The dao is the source of all reality.
The Dao (as the source of all reality) is not a
thing (not a being or substance).
.
It is beyond distinction and thus beyond the
definitional powers of language.
Definitions are intended to distinguish things, so
how could you define something that is the
source for all distinctions?
So the Dao is called “the nameless,” that is, the
indefinable.
It is non-being, but not in the Western sense of
“no-thing-ness.” It is real, but not a thing.
Lao-tzu compares it to “positive emptiness” (like
the hole-part of a hole or the empty space
inside a bowl).
Dao (Way) de (Power) Jing (Book)
The Dao de Jing is a book (jing) about the
excellence or power (de) of the Way (dao).
The excellence (power or perfection) of each
thing is called its de, and this is the dao
manifesting itself on the individual level.
To actualize the potential of one’s nature is an
excellent way to exhibit one’s de.
Nature does it – well – naturally.
For human beings, this actualization occurs by
living in accord with the Dao.
What is the Tao?
We read in the Daodejing that “The tao that can be told
is not the eternal Tao.”
The eternal Tao is nameless.
It is basically indefinable.
It has to be experienced.
Tao is the origin of everything, and all things are
manifestations of the Tao.
It "refers to a power which envelopes, surrounds and
flows through all things, living and non-living. The
Tao regulates natural processes and nourishes
balance in the Universe. It embodies the harmony of
opposites (i.e. there would be no love without hate,
no light without dark, no male without female)."
…
To experience the Tao, we must leave behind our concern for
individual things, such as how much something costs, what time it
is now, whether something is big or small, and so forth.
The Taoist way of seeing things seems so odd to some people that at
first it seems like trying to see in the dark, as the end of the 1st
chapter of the Tao Te Ching describes:
Darkness within darkness –
The gate to all mystery.
The Tao cannot be perceived directly but rather by intuition, although
it can become “visible” to us as we contemplate and take on some
of the qualities of the “images” of the Tao.
The Tao cannot be perceived directly but rather by intuition, although
it can become “visible” to us as…
we contemplate and take on some
of the qualities of the “images” of the Tao.
Several common images are:
Water – water is gentle, ordinary, and lowly, but strong and
necessary. It flows around every obstacle. The highest good is
like water, because it assists all things and does not compete with
them.
Woman – the female is sensitive, receptive, yet effective and
powerful. The Tao nourishes and is the great mother.
Child – the child is full of energy, wonder, and naturalness. As we
age, we typically lose these things, and as we begin to live in
harmony with the Tao, these things are restored.
Valley – the valley is yin, and it is mystery.
Darkness – darkness can be safe, full of silence and possibility.
Wu wei is the way of Dao and literally means “no action”
(or “effort-less-ness”).
It is the way the Dao acts – the way that is no-thing acts by
not acting.
It just is and does.
One common example in the Dao de Jing of this
effortlessness is the water flows. It just does. It doesn’t
force itself upon anything or strive to accomplish
anything. It just “goes along with the flow.”
There is nothing artificial in natural events. Nature acts
spontaneously, freely, and naturally.
Nature does not calculate how to act; it just acts.
.
There is no “good” and “bad” Dao (way). There is just the
.
Dao.
And because no identity or distinction (which is where we
get the notion of identity) is “fixed” in the Dao, there are
no opposites at all (much less good and bad
distinctions).
Because all things are interconnected in the Dao,
everything is in “process” of becoming something else.
Nothing is stagnant. All things are changing.
This is the fundamental notion behind the concept of yin
and yang.
Yin & Yang
This is a well known Taoist symbol. "It represents the balance of opposites
in the universe. When they are equally present, all is calm. When one is
outweighed by the other, there is confusion and disarray."
One source explains that it was derived from astronomical observations
which recorded the shadow of the sun throughout a full year.
The two swirling shapes inside the symbol give the impression of change - the only constant factor in the universe.
One tradition states that Yin (or Ying; the dark side) represents the breath
that formed the earth. Yang (the light side) symbolizes the breath that
formed the heavens.
The most traditional view is that 'yin'
represents aspects of the
…
feminine: being soft, cool, calm, introspective, and healing and that
‘yang’ the masculine: being hard, hot, energetic, moving, and
sometimes aggressive. Another view has the 'yin' representing
night and 'yang' day.
However, since nothing in nature is purely black or purely white, the
symbol includes a small black spot in the white swirl, and a
corresponding white spot in the black swirl. The circle in the
middle of each “teardrop” is to indicate that even as things are
moving from one to the other, there is always still some yang in yin
and some yin in yang.
Ultimately, the 'yin' and 'yang' can symbolize any two opposing forces
in nature. They are never totally distinct from each other nor can
they be separated. Everything moves from yin to yang and yang
to yin – never stopping in the transitional process from one to the
other.
Taoists believe that humans intervene in nature and upset the
balance of Yin and Yang. The point is to restore them into a
whole.
.
So the Dao, which is not a thing, acts naturally, freely,
spontaneously, unselfishly, without force, thereby
producing and sustaining a universe of harmonious
processes in such a way that it is possible for each
individual thing to manifest its own excellence.
This is the way of nature, the way of genuine reality.
This is the Way (dao).
1. The Way
.
The Way that can be experienced is not true;
The world that can be constructed is not true.
The Way manifests all that happens and may happen;
The world represents all that exists and may exist.
To experience without intention is to sense the world;
To experience with intention is to anticipate the world.
These two experiences are indistinguishable;
Their construction differs but their effect is the same.
Beyond the gate of experience flows the Way,
Which is ever greater and more subtle than the world.
1. The Way
2. Abstraction
2. Abstraction
When beauty is abstracted
.
Then ugliness has been implied;
When good is abstracted
Then evil has been implied.
So alive and dead are abstracted from nature,
Difficult and easy abstracted from progress,
Long and short abstracted from contrast,
High and low abstracted from depth,
Song and speech abstracted from melody,
After and before abstracted from sequence.
The sage experiences without abstraction,
And accomplishes without action;
He accepts the ebb and flow of things,
Nurtures them, but does not own them,
And lives, but does not dwell.
.
3. Without Action (Wu wei)
Not praising the worthy prevents contention,
Not esteeming the valuable prevents theft,
Not displaying the beautiful prevents desire.
In this manner the sage governs people:
Emptying their minds,
Filling their bellies,
Weakening their ambitions,
And strengthening their bones.
If people lack knowledge and desire
Then they can not act;
If no action is taken
Harmony remains.
.
13. Self
Both praise and blame cause concern,
For they bring people hope and fear.
The object of hope and fear is the selfFor, without self, to whom may fortune
... and disaster occur?
Therefore,
Who distinguishes himself from the
…world may be given the world,
But who regards himself AS the world
…may accept the world.
14. Mystery
Looked at but cannot be seen - it is beneath form;
Listened to but cannot be. heard - it is beneath
…sound;
Held but cannot be touched - it is beneath feeling;
These depthless things evade definition,
And blend into a single mystery.
In its rising there is no light,
In its falling there is no darkness,
A continuous thread beyond description,
Lining what can not occur;
Its form formless, Its image nothing,
Its name silence;
Follow it, it has no back, Meet it, it has no face.
Attend the present to deal with the past;
Thus you grasp the continuity of the Way,
Which is its essence.
22. Home
Accept and you become .whole,
Bend and you straighten,
Empty and you fill,
Decay and you renew,
Want and you acquire,
Fulfill and you become confused.
The sage accepts the world
As the world accepts the Way;
He does not display himself, so is clearly seen,
Does not justify himself, so is recognized,
Does not boast, so is credited,
Does not pride himself, so endures,
Does not contend, so none contend against him.
The ancients said, "Accept and you become whole",
Once whole, the world is as your home.
.
23. Words
Nature says only a few words:
High wind does not last long,
Nor does heavy rain.
If nature's words do not last
Why should those of man?
Who accepts harmony, becomes harmonious.
Who accepts loss, becomes lost.
For who accepts harmony, the Way harmonizes
…with him,
And who accepts loss, the Way cannot find.
25. Beneath Abstraction
There is a mystery,
Beneath abstraction,
Silent, depthless,
Alone, unchanging,
Ubiquitous and liquid,
The mother of nature.
It has no name, but I call it "the Way";
It has no limit, but I call it "limitless".
.
Being limitless, it flows away forever;
Flowing away forever, it returns to my self:
The Way is limitless,
So nature is limitless,
So the world is limitless,
And so I am limitless.
For I am abstracted from the world,
The world from nature,
Nature from the Way,
And the Way from what is beneath abstraction.
PLATONIC DUALISM
Alfred North Whitehead once remarked that “all
Western philosophy is but a footnote to Plato’s
Republic.”
Plato’s ideas have influenced and continue to
influence people who do not even know his
ideas or even his name.
He was the student of Socrates and the teacher
of Aristotle, and even the Apostle Paul quotes
him in the New Testament of the Bible.
Do you believe in the immortality of the soul?
.
Do you think there is both a material and
immaterial reality?
Do you think that logical and mathematical
methods of reasoning are ideal models for
arriving at truth?
Do you believe all things have an essential
nature?
Do you think virtue is its own reward?
Do you believe you should control your passions
(emotions) by the use of reason?
Do you think you are more than a body and
mind?
UP
THERE!
.
OUT
THERE!
BETTER
TASTE!
LESS
FILLING!
Plato and Aristotle arguing about the “really real.”
Plato’s Metaphysics
“Metaphysics” means questions about knowing
the reality that we call “reality.” Physics
studies reality; metaphysics asks questions
about how we can even know anything about
reality. So metaphysics is “above/before
reality.”
Plato’s “reality” is called “dualistic,” because he
says that it can be divided into two radically
different things (one of which is NOT really
“real”).
There is the world/realm of matter which is
. and imperfection. It
characterized by change
is always in the state of becoming something
or decaying and passing away. This Sensible
Realm in which we live is a world of
impermanence. While matter is not denied, it
is still less real than the Forms (or Ideas).
The true reality is the realm of Forms or Ideas,
and it is characterized by permanence (being).
But being is immaterial and obviously, since it
is unchanging and is the really real, it is of
greater value than the material realm.
The English word “form” is often used to translate
the Greek word for idea or concept. So in the
.
Theory of Forms, we are talking about the
mental idea or concept of something.
We have an idea about a table when we see a
table, but where did you get this idea of table to
begin with?
Plato thinks that all ideas exist in their perfect and
unchangeable state in the Intelligible Realm.
Things we experience in the Sensible Realm are
copies of the real Ideas that exist in the
Intelligible Realm. But things here are
imperfect copies, because only the Forms
themselves are perfect and the source of all
reality.
For example, think of something you regard as
. in the sensible world
“truly beautiful.” Things
are beautiful to the extent that they "imitate" or
"participate" in the Form of Beauty; however,
these beautiful things will break or die. But
Beauty Itself (the Form) is eternal. It will
always "be."
The same can be said of Truth and Justice.
And this eternalness of the perfect Idea is also
true for "vaseness" or "toothpickness" or
"manness“ and even “tableness; particular
things "participate" in their eternal Form.
When we see something in the
Sensible Realm, we recognize
it
.
because we have an idea of it
(since our souls/minds have
already “seen” it - and thus
know it - in & from the
Intelligible Realm).
PROVE IT !!!!!
2 ft
2 ft
Plato records in the Meno that Socrates
was asked to prove that we already
“know” the Forms (or Ideas).
So he took an uneducated slave boy and
asked him to take a 2 foot
square and to double its area.
2 ft
2 ft
The area inside a 2 foot square is 4 feet.
We want to double the area from 4ft to 8ft in area.
4 ft
3 ft
4 ft
4 is twice 2, BUT
4 x 4 = 16 - That’s twice
the area size that we want
3 ft
3 x 3 = 9 - We’re getting
closer, but 9 is still bigger
than 8, so it’s not twice
the area of 4 feet either
The original area was 4 ft, and the new shape below has 8 ft.
Each quarter of the original square had an area of 1 ft, so….
using the
outside lines
of the original
2 ft
square as
the diagonals
To find the
If this
hypotenuse
for the new
helps  of a triangle:
square, the
a2 + b2 = c2
new area will
[Note: It
be twice the
won’t
size of the
help ]
original
square.
2 ft
.
Obviously the slave boy already “knew” mathematical Forms.
Have you ever truly studied an Oreo cookie?
.
How is it possible that all the Oreo cookies in the
world look so much like
. each other?
Well, you say, there must be a mold some
where they use to make the cookies. There
must be a perfect “form” for an Oreo cookie
that Nabisco uses.
But while you are studying your Oreo cookie, do
you also notice that no matter how close to
perfect it is, there is always a little corner
chipped off, or its too thick or too thin on one
side, or the letters and patterns are not quite
as distinct as they could be.
You know that the mold or form they use to
make the cookies is perfect….
.
…even if the cookies themselves are not.
That’s exactly the difference between the Forms
and the things in the sensible world that
participate in the Forms.
. But how can we ever
be certain that we
know the “really real”
eternal and perfect
ideas/forms and that
we are not just
settling with a “bad,
imperfect, and
temporal copy”?
Fortunately, Plato
explains how.
The Cave (Allegory of Enlightenment)
1--prisoners are chained in such a way that the
face the back of the wall of the cave; they can
see nothing to either side (not even each other),
and they can only see the shadows cast by
things passing between the cave wall and a fire
someplace behind them
--between the fire and the prisoners, there is a
wall high enough that they cannot see people
walking, but shadows are cast of the vases,
statues, or other artifacts which are being
carried upon their heads
--the prisoners can hear echoes of voices and
see the shadows, and they mistake these
echoes and shadows for reality
2--somehow one prisoner becomes unchained;
he turns around and is forced to look at the true
source of the shadows, but the fire pains his
eyes.
--he prefers the pleasant deception of shadows
3--behind and above the fire is the mouth of the
cave, and outside in the bright sunlight (only a
little of which trickles into the cave) are trees,
rivers, mountains, and sky
.
4--now the former "prisoner" is forced "up the
steep and rugged ascent" (Plato's allegory of
education) and brought to the sunlit exterior
world
--but, again, he is at first blinded by the light
--he must first look at the shadows of the trees
and mountains; he can only look at the
reflection of the sun in the water
--but after he gets used to seeing things in the light of
the sun, he is able to see the sun itself (the allegory of
enlightenment)
5--if this enlightened man were to return to the cave,
he would appear ridiculous because he would see
.
sunspots everywhere and not be able to penetrate
the darkness
--if he tried to liberate (free) his fellow prisoners, they
would be so angry at him for disturbing their illusions
that they would grab him and kill him (this is a clear
allusion to the death of Socrates)
The allegory of the liberation of the slave from the
darkness, deceit, and untruth, and the hard journey
to the light and warmth of. the Truth, is more than just
a poetic vision.
Plato gives it precise technical application in the
"Simile of the Line."
Symbolism:
The World Outside the Cave = The Intelligible World
The Sun = The Form of the Good
Objects in the Outside World (Trees, etc.) = The Forms
Shadows & Reflections in Outside World = Concepts
The World Inside the Cave = The Physical World
The Fire = The Sun
The Objects (Statues) that Cast the Shadows =
Particular Objects
The Shadows on the Wall = Images
The REALLY Real
.
But Plato’s version of Idealism (the notion
that the “real” are Ideas) is going to get
topped by George Berkeley.
Even though Plato thought the “really real”
was the Realm of Ideas, he still believed
that the material world existed – but just as
a “bad copy” of the Really Real.
Berkeley was not going to be that generous.
Berkeley’s
“Subjective Idealism”
Berkeley argues that reality consists of (1) finite
or created minds (human), (2) an infinite mind
(God), and (3) the ideas (thoughts, feelings,
and sensations) that these various minds
have.
This idealism is “subjective” because physical
objects do not exist apart from some subject
(mind) who perceives them.
Before going on with Berkeley...
we need a little refresher
from last week
REALISM: Knowing
The “Really Real”
.
RATIONALIST:
Cartesian Realism –
What you see is not
what you get (since
you’re getting
geometrical figures).
Reality is in the mind;
it’s not “out there” to
see; ideas (and
innate ones at that)
are “real.”
Descartes’ dog
.
EMPIRICISTS
Naïve or Direct Realism – What you see is
what you get (like a photograph); our sense
put us in touch with reality
Dog in the world
Dog in the mind
.
Dog in the world
Representative or Indirect Realism (John
Locke) – The mind “represents” the external
world to itself but does not duplicate it (e.g.,
you see a shaggy dog, and the mind sees this
or this
figure)
Sensations indirectly represent objects that exist outside the mind.
. Subjective Realism
(George Berkeley) –
Reality exists only if
there is some
“subject” who is
perceiving it as an
idea; fortunately, God
is always perceiving,
even if we are not
Q: If a tree falls in the forest and no one is there to
hear it, does it make a noise?
A: Yes. God hears it.
Descartes had said that.primary qualities (size,
weight, any measurable quality) exist in an
external object (think about the wax), but we
perceive our ideas in our minds about the
object. The secondary qualities (color, taste,
etc) are completely in us and thus unreliable.
Locke had added that that we perceive both the
primary and secondary qualities (which are in
the object) through our senses, but our mind
represents these perceptions from which we
form ideas of things in the material world.
And now Berkeley….
Berkeley was an undergraduate in college when
he read Locke and Descartes, and he partially
agreed with Descartes (that we can know our
ideas about objects in the outside world) and
partially agreed with Locke (that our minds
represent our perceptions from our senses
about the outside world as ideas).
Locke was allowing the senses to accurately
represent the world, and Descartes was ONLY
allowing ideas about the outside world that are
“clearly and distinctly” known in our minds
about the world to be true.
So using Cartesian thinking,
. Berkeley
challenged Locke’s notion and asked, “If all we
can really know, whether we are talking about
primary or secondary qualities, are our ideas
of the perceptions formed from our sense
experience, how do we really know that there
is anything out there upon which our sense
perceptions are actually based?
In other words, if all I can know are the ideas,
how can I know there even IS a world “out
there” beyond what I can know in my mind?
To know this picture is a
likeness of your instructor,
you could look at your
instructor and compare that
image with the photo
image.
However, you cannot do
that with your senses
because you can never get
outside of your sensations
to compare them with the
physical objects that
supposedly caused the
sensations.
Berkeley thought Locke had created a duplex
world: we have a world
. of physical objects
duplicated by a world of mental images.
Why not simplify it, Berkeley thought, by getting
rid of physical objects?
If it’s true that we only know our ideas about the
sensations, we have no way of knowing or
being able to prove that there is anything
actually causing the sensations.
People who have had limbs amputated still have
“perceptions” of feelings in the amputated
limbs which no longer exist, but they can know
that their ideas about those perceptions are
real, even if the perceptions themselves are
wrong.
Although Berkeley does NOT deny that it is
.
possible that a material world truly exists out
there, he did say that we cannot “prove” it
really exists.
But it seems reasonable to “believe that it does,
because sensations “normally” cannot exist
without being sensed.
The other empiricists had said that all we can
know is what we have experienced through
our senses (recall Locke’s “blank slates”).
Berkeley’s conclusion, however, is that nothing
can exist without being experienced. To be is
to be perceived – esse es percipi.
If it is not perceived, we can not say it exists.
Most empiricists start with the notion that there
is a material world which
. we perceive through
our senses and then from these sense ideas
that we experience, we derive knowledge
about the world.
For Berkeley, there is no reason to postulate a
material world in order to say “from these
sense ideas that we experience, we derive
knowledge about the world.”
Berkeley is an empiricist, but he is not a
materialist. Like Plato, he is an Idealist – the
“real” are the ideas we have about the world.
The only things we can know are things that
appear to our minds as sensations, feelings,
and ideas.
And some GOOD News!
Remember that Hume said
that there was no ego or
“I” – just some
continuous perceptions
that made you think that
you were a “me”?
Berkeley notes that you
have to perceive the
perceiver (i.e., you) when
you think about the ideas you perceive. So YOU
and Berkeley exist!!! (well, he existed before he died)
.
Any Questions?
.