Can Science tell us the Truth about the Real?

SCIENCE andSCIENCE andthe REALLY REALthe REALLY 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 SciencePhilosophy 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

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).

.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.

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?

.

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.

So science is concerned with the lawsof nature, and it is here that science seems to go beyond common-sense.

.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 deductive-nomological 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 crowwe 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?

DaoismDaoismThe 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

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.

.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 abstractedThen ugliness has been implied;When 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 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 desireThen they can not act;If no action is takenHarmony remains.

.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.

.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 worldAs 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 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.

.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 DUALISMPLATONIC 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?

.

Plato and Aristotle arguing about the “really real.”

UPUPTHERE!THERE!

OUTOUTTHERE!THERE!

BETTERBETTERTASTE!TASTE!

LESSLESSFILLING!FILLING!

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

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.

.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

“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.

.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).

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

PROVE IT !!!!!

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 x 4 = 16 - That’s twicethe area size that we want

4 is twice 2, BUT3 x 3 = 9 - We’re gettingcloser, but 9 is still biggerthan 8, so it’s not twicethe area of 4 feet either

4 ft

4 ft

3 ft

3 ft

2 ft

2 ft

.Obviously the slave boy already “knew” mathematical Forms.

To find thehypotenuseof a triangle:a2 + b2 = c2

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….

If thishelps

[Note: Itwon’t

help ]

using theoutside lines

of the original square as

the diagonalsfor the newsquare, the

new area willbe twice thesize of the

originalsquare.

.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 CaveThe Cave (Allegory of Enlightenment)(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 Berkeley’s “Subjective Idealism”“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: KnowingThe “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

.

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)

Dog in the world

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)

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Any Questions?.