Can Science tell us the

1
SCIENCE and the REALLY REAL
Can Science tell us the Truth about the Real?
2
(No Transcript)
3
.

• 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)?

4
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.

5
.

• We live in an age the puts a great deal of trust
  in science to tell us the truth and nothing but
  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).

6
.

• Some people believe that studying the 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.

7
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?
• Youre probably thinkingScience explains things.
  It answers the why and how questions about
  natural events. It explains what causes what.

8
.

• 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.

9
.

• 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?

10
.
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.

11
(No Transcript)
12
.

• 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?

13
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 didnt reject the deductive-nomologica
  l model, he did try to refocus the attention of
  philosophers of science on issues surrounding the
  testability of what he liked to call
  conjectures.

14
.

• 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.

15
If we could prove that there were no white
crows, we would know with certainty that the next
crow we saw would be black.
16
Poppers 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.

17
.

• 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.

18
.

• Poppers positive comments on Einsteins theory
• The problem with verification theories was
  precisely this factthat they always fitted, that
  they were always confirmedwhich 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 observationin 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.

19
Poppers Rules

• It is easy to obtain confirmations, or
  verifications, for nearly every theory if we
  look for confirmations.
• 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.
• Every "good" scientific theory is a prohibition
  it forbids certain things to happen. The more a
  theory forbids, the better it is.
• 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.

20
.

• 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.")

21
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.

22
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.

23
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.

24
.

• 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).

25
.

• 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.

26
.

• 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.
• The new theory should be independently testable
  it must lead to the prediction of phenomena which
  have not so far been observed.
• 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.

27
.

• POPPERS 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 dont 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.

28
.

• 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?

29
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.

30
ONTOLOGY the study of being

• For something to be real, it must exist. Right?
• For something to exist, it must be identifiable
  and different from other things. Right?
• For something to exist, it must be permanent (for
  as long as it exists). Right?
• For something to exist, it must have substance.
  Right?
• Well, maybe not (according to the Dao Plato).

31
.

• 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.

32
.

• The Dao or the really real according to the Dao
  de Jing exists, but it is not independent 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.

33
.

• 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).

34
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 ones nature is an
  excellent way to exhibit ones de.
• Nature does it well naturally.
• For human beings, this actualization occurs by
  living in accord with the Dao.

35
(No Transcript)
36
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)."

37

• 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.

38

• 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.

39
.

• 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 doesnt 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.

40
.

• 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.

41
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.

42

• 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.

43
(No Transcript)
44
.

• 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).

45
.

• 1. The Way
• The Way that can be experienced is not trueThe
  world that can be constructed is not true.The
  Way manifests all that happens and may
  happenThe world represents all that exists and
  may exist.To experience without intention is to
  sense the worldTo experience with intention is
  to anticipate the world.These two experiences
  are indistinguishableTheir 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.

46
1. The Way
2. Abstraction
47
.

• 2. Abstraction
• When beauty is abstractedThen ugliness has been
  impliedWhen good is abstractedThen 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 actionHe
  accepts the ebb and flow of things,Nurtures
  them, but does not own them,And lives, but does
  not dwell.

48
.

• 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 peopleEmptying
  their minds,Filling their bellies,Weakening
  their ambitions,And strengthening their
  bones.If people lack knowledge and desireThen
  they can not actIf no action is takenHarmony
  remains.

49
.

• 13. Self
• Both praise and blame cause concern,For they
  bring people hope and fear.The object of hope
  and fear is the self- For, 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.

50
.

• 14. Mystery
• Looked at but cannot be seen - it is beneath
  formListened to but cannot be heard - it is
  beneath soundHeld but cannot be touched - it
  is beneath feelingThese 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 occurIts form
  formless, Its image nothing,
• Its name silenceFollow it, it has no back,
  Meet it, it has no face.
• Attend the present to deal with the pastThus
  you grasp the continuity of the Way,Which is its
  essence.

51
.

• 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 worldAs
  the world accepts the WayHe 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.

52
.

• 23. Words
• Nature says only a few wordsHigh wind does not
  last long,Nor does heavy rain.If nature's words
  do not lastWhy 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.

53
.

• 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 foreverFlowing away forever, it returns to
  my selfThe 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.

54
PLATONIC DUALISM

• Alfred North Whitehead once remarked that all
  Western philosophy is but a footnote to Platos
  Republic.
• Platos 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.

55
.

• 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?

56
.
UP THERE!
OUT THERE!
BETTER TASTE!
LESS FILLING!
Plato and Aristotle arguing about the really
real.
57
Platos 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.
• Platos reality is called dualistic, because
  he says that it can be divided into two radically
  different things (one of which is NOT really
  real).

58
.

• There is the world/realm of matter which is
  characterized by change and imperfection. It 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.

59
.

• 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.

60
.

• For example, think of something you regard as
  truly beautiful. Things in the sensible world
  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.

61
.

• 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 !!!!!
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
62
2 ft
2 ft
The area inside a 2 foot square is 4 feet.
63
We want to double the area from 4ft to 8ft in
area.
4 ft
3 ft
4 ft
3 ft
3 x 3 9 - Were getting closer, but 9 is
still bigger than 8, so its not twice the area
of 4 feet either
4 is twice 2, BUT
4 x 4 16 - Thats twice the area size that we
want
64
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 square
as the diagonals for the new square, the new area
will be twice the size of the original square.
2 ft
To find the hypotenuse of a triangle a2 b2 c2
If this helps ?
Note It wont help ?
2 ft
.Obviously the slave boy already knew
mathematical Forms.
65
.

• Have you ever truly studied an Oreo cookie?

66
.

• 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.

67
.

• even if the cookies themselves are not.
• Thats exactly the difference between the Forms
  and the things in the sensible world that
  participate in the Forms.

68
.

• 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.

69
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

70
(No Transcript)
71
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
72
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
73
.

• 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

74

--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)
75

76
.

• 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)

77
.

• 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."

78
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

79
The REALLY Real
80
.

• But Platos 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.

81
Berkeleys 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.

82
Before going on with Berkeley...

• we need a little refresher
• from last week

REALISM Knowing The Really Real
83
.

• RATIONALIST
• Cartesian Realism What you see is not what you
  get (since youre getting geometrical figures).
• Reality is in the mind its not out there to
  see ideas (and innate ones at that) are real.

Descartes dog
84
.

• 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
85
.
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.
86
.

• 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.
87
.

• 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.

88
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.

89
.

• So using Cartesian thinking, Berkeley challenged
  Lockes 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?

90
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.
91
.

• 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 its 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.

92
.

• 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 Lockes blank slates).
• Berkeleys 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.

93
.

• 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.

94
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)
95
(No Transcript)
96
. Any Questions? .