Transcript An Epistemology Update John Rafferty Langside College Glasgow Tel: 0141 272 3875

An Epistemology Update
John Rafferty
MA MSc PGCE
Senior Lecturer Social Sciences
Langside College Glasgow
[email protected]
Tel: 0141 272 3875
Section 1
Philosophical Issues
in Epistemology
Outcome 1

Demonstrate an understanding of
the philosophical issues in the area
of epistemology:
The Tripartite Theory of Knowledge
 Philosophical Problems with the
Tripartite theory
 Scepticism, Rationalism and Empiricism

Question 1
Why are knowledge
claims a problem in
philosophy?
Appearance and Reality

Perceptual problems
• Colour blindness; hallucinations

Optical illusions
• The stick in water isn’t bent

Atmospheric effects
• Mirages as they appear; Stars don’t twinkle

Time lapse illusions
• Some stars no longer exist

Radical philosophical doubt
• Descartes’ Demon; Plato’s Cave; The Matrix; Brain
in a Jar
Illusions of perspective
Light refraction
Objects on the horizon
Railway tracks
Belief, Knowledge & Certainty

Belief
• A proposition that is held to be true but
without sufficient evidence to convince
others

Knowledge
• A proposition that is believed, is true and
can be supported by evidence

Certainty
• A proposition where there is no doubt
about its truth
Question 2
What is knowledge?
‘Knowing how’ v ‘knowing that’

A distinction associated with Gilbert Ryle (1900-1976)

Knowing that
• Facts and information; propositional knowledge; “I know that
Berlin is in Germany”

Knowing how
• An ability or skill; a dispositional or operational knowledge; “I
know how to bake bread”


Most of epistemology has been concerned with knowing
that, especially classical debates
Can all cases of ‘knowing how’ be reduced to collections of
‘knowing that’?
• E.g. Knowing how to drive a car


Is knowing that useless without knowing how?
Is innatism only tenable as applied to knowing how?
The Tripartite Theory of
knowledge


A classical definition of knowledge
An agent (A) can be said to know a
proposition (P) if:





P is true (the truth condition)
A believes P (the belief condition)
A has sufficient evidence for P (the evidence
condition
This definition of knowledge is called
“Justified true belief”
Having two of these conditions is not
enough to count as knowledge.
The Hesitant Student


Teacher: Billy, what is
3x7?
Billy: Er…(guesses) is it
21?


In this case p is true (3x7
is 21) and Billy has
evidence for p (he has
been to the classes) but he
doesn’t believe P.
Is this a case of
knowledge?
The Lucky Punter

A gambler finds a four leaf
clover so bets on a horse that
day believing that his horse
will win now that he has this
lucky charm. The horse does
win.


In this case p is true (the horse
did win) and the punter believed
p (he sincerely thought the
horse would win) but his
evidence for this belief seems
inadequate.
Is this a case of knowledge?
Santa’s Visit

Many children believe in Santa
Claus. They leave cookies out for
him that are eaten the next
morning and as promised the
presents arrive every Christmas
day. Parents, shopkeepers and
teachers all reinforce this belief.


In this case the children believe P
(they think Santa is real) and have
evidence for believing P (teachers and
parents confirm it) but P isn’t true
Is this knowledge?
Problems with the tripartite theory

The Gettier Problem



Infinite regress argument


Smith has applied for a job, but has a justified belief that
"Jones will get the job". He also knows that "Jones has 10
coins in his pocket". Smith therefore concludes that "the man
who will get the job has 10 coins in his pocket".
In fact, Smith gets the job but, as it happens, also has 10
coins in his pocket. So his belief that "the man who will get
the job has 10 coins in his pocket" was justified and true but
isn’t knowledge.
Every justification in turn requires justification and arguably
this demand for justification is never sated.
Some justifications are unreliable



Sense experience is prone to deception
Innate ideas are controversial
Analytic truths are trivially true
Question 3
Can knowledge
claims be justified?
Rationalism and Empiricism

Rationalism







Reason is the source of all
knowledge
Mind contains innate
ideas
Maths is a model for
knowledge
Knowledge can be gained
a priori
Knowledge can be certain
The senses are easily
fooled
Examples: Plato,
Augustine; Descartes;
Leibniz

Empiricism







The senses are the source
of all knowledge
Mind is a ‘tabula rasa’
Biology is a model for
knowledge
Knowledge is only gained
a posteriori
Knowledge can only ever
be probable
Reason only gives us
access to uninformative
tautologies
Examples: Aristotle (?)
Locke; Berkeley; Hume
Section 2
Classic Texts in
Epistemology
Outcomes 2 & 3

Critically analyse a standard philosophical position in the
area of epistemology:




Describe the epistemology of Descartes or Hume
Explain the reasoning and assumptions on which this account
is based
Cite specific extracts
Critically evaluate a standard philosophical position in the
area of epistemology:



Explain the strengths and weaknesses of Descartes or Hume
Present a conclusion on the persuasiveness of this account
Give reasons in support of this conclusion
Section 2: Option 1
René Descartes
René Descartes
Meditations
on First Philosophy
Historical Context







The Renaissance
The end of
Scholasticism
Rebirth in knowledge
Flourishing in the arts
Architecture
Painting
Science
Historical Context

The Reformation





Split in the church
Birth of Protestantism
Catholic dominance ends
Europe divided
Martin Luther
Historical Context

Discovery of the New World
New cultures and peoples
 New world view

René Descartes
Meditation 1
The Sceptical
Method
Method









Assume nothing
Start afresh
Re-examine his beliefs
Focus on foundational beliefs
Reject obvious falsehoods
But also reject even slightly doubtful beliefs
Looking for 1 certainty to base his knowledge on
Architectural metaphor
Barrel of apples analogy
Attacking Sense Experience




Objects in the distance
Small objects
Other arguments from illusion are
possible
But surely apart from these the senses
are reliable?
Dreaming Argument




A stronger argument
against sense
experience
Any given sense
experience can be
replicated in dreams
Hence sense
experience is
unreliable
In fact, there is
never any sure way
of distinguishing
dreams from reality
A Priori truths





Dreams are like paintings
They must be based on
reality
Or at least the colours
and shapes must be real
Whether awake or asleep
a square still has 4 sides
Hence maths and
geometry escape the
dream argument and
may be reliable
Do all dreams contain some
knowledge?
The Demon Hypothesis






An argument against a priori
knowledge
The ultimate in scepticism
A test which any candidate for
certainty must pass
Imagine a demon were fooling
us in everything we see and
think
If this scenario were true,
could anything still be certain?
This idea has reappeared in
different forms
René Descartes
Meditation 2
Finding Certainty
The Search for Certainty






Restates his sceptical
approach
Like Archimedes he is
looking for 1 fixed point
Assumes he has no
body
Assumes everything
revealed by the senses
is a lie
Assumes the Demon
fools him at every turn
Can anything be known
if we assume all this?
The Cogito

Cogito ergo sum



Defeats the Dreaming Argument


You must exist to be fooled
A self-authenticating statement


you must exist to dream
Defeats the Demon Hypothesis


I am, I exist (Meditations)
I think therefore I am (Discourse)
You affirm its truth each time you
think it
But surely we know external
objects better than we know the
mind?
Rationalism and
Empiricism

A major dispute running through the entire
history of philosophy has to do with the
source(s) of human knowledge. There are two
major schools: rationalism and empiricism.

The empiricists hold that knowledge is derived
from sense perception and experience.

The rationalists (such as Descartes) hold that
knowledge is derived from clear logical
thinking, from the intellect (i.e., from
"reason").
The Wax Example



Wax has one set of properties when
cold
But all its properties change when
heated
Yet we still think it’s the same wax.
Why?




It can’t be the senses that tells us
this - they give conflicting reports
Can’t be imagination either - wax
can change more ways than we can
imagine
So it must be pure mental scrutiny
that reveals the true nature of the
wax
Hence Rationalism should be
adopted over Empiricism
Perception




In fact all perception is
really a case of mental
judgement
We say we see a man
crossing the square
Yet all we see are a hat
and cloak which could
conceal an automaton
Our judgements go
beyond what we strictly
have sense experience
for
René Descartes
Meditation 3
Rebuilding
knowledge
Rebuilding Knowledge

1.
2.
Descartes’
strategy in
rebuilding
knowledge rests
on 2 central
claims:
The clear and
distinct rule
The existence of
a benevolent
God
The Clear and Distinct Rule

What is it that convinces us of the
truth of the Cogito?





It is a “clear and distinct” perception
A psychological state which gives rise to
irresistible certainty
Hence anything else which is clear
and distinct must also be certain
This rule can now be used to rebuild
knowledge by identifying other truths
God’s existence, for example, can be
known clearly and distinctly
The Trademark Argument

This argument in Meditation 3 helps
support the clear and distinct rule

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We have an idea of God in our mind
This idea must have a cause
There must be as much reality in the
cause as in its effect
The cause of the idea is God
The idea is like a trademark left in our
minds by God
The idea of God includes the notion that
he is benevolent
Hence God is no deceiver
Hence whatever we perceive distinctly
must be true since a benevolent God
wouldn’t allow this level of deception
René Descartes
Meditation 6
Resolution of Earlier
Doubts
Naïve Realism



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
The simplistic view that unreflective
people have
External objects present themselves
to the senses unbidden
They are more distinct than those
presented by memory or imagination
They can’t come from within so must
come from without
It seems that the sense comes first
and the intellect later
So nothing is present to the mind
that was not first present to the
senses
Rejection of Naïve Realism





Descartes refers to arguments from
Meditation 1
Objects at a distance
Phantom limbs
 Demonstrate the fact that senses
don’t always report the truth
Dreaming argument
 I don’t believe the objects in
dreams are located outside of me
so why make this assumption
when awake?
But must we resort to scepticism?
Rejection of Scepticism



Although we shouldn’t heedlessly
accept sense reports, neither should
we heedlessly reject them
We have a passive faculty for receiving
ideas of objects but there must be an
external cause to the ideas we receive
These causes can only be:


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External objects
God
The demon
God is not a deceiver so wouldn’t allow
us to think that these ideas were
caused by external objects when they
weren’t
Sense Experience




There is an outside world
However it may not exist in the way it is
presented by my senses
Everything I am taught by nature contains
some truth
God equips us with a number of faculties:




Reason
The Senses
Memory
It is impossible that there could be any
falsity in my opinions which couldn’t be
corrected by some faculty supplied by God
How is Error Possible?

Some things which my senses appear to be telling
me are in fact a misjudgement of reason

“Grass is green”
• Grass stimulates sensations of green in us

“The tower is small”
• The tower simply appears small and my memory and other
senses can confirm its true size

“My amputated foot causes pain”
• Feelings of pain from a distant body part could equally be
caused by stimulating parts in between

With the judicial use of clear reasoning we can
correct the errors of the senses
The Dream Argument



Dreams have no consistency
between one dream and the
next.
 Life picks up from where it
left off but dreams do not
The laws of nature are broken
in dreams
 People can fly or talk to
dead people
By the application of reason
we can distinguish the two
states when we are awake
The Demon Hypothesis
If there were a
demon, a benevolent
God would not allow
him to interfere with
our perceptions
 The hypothetical
possibility of the
demon is therefore
no longer a threat

Section 2 Option 2
David Hume
David Hume
Enquiry Concerning
Human Understanding
Background



Empiricist Philosopher and
Historian
A pivotal figure of the Scottish
Enlightenment along with Adam
Smith (1723-1790) and Thomas
Reid (1710-1796)
Key Works:

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A Treatise of Human Nature (1740)
An Enquiry Concerning Human
Understanding (1748)
Dialogues Concerning Natural Religion
(1779)
Influences

Heavily influenced by John Locke (1632-1704), Sir Isaac
Newton (1642 – 1727) and Bishop George Berkeley
(1685-1753).

Hume gets his notions of Empiricism, Representative
Realism, and Scientific Method from them.
Hume’s Enquiry

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Inspired by the empirical successes
of Isaac Newton wants to do the
same for the human mind.
He is undertaking a psychological
study of man.
Trying to uncover the fundamental
principles of human reasoning.
His method is one of empirical
observation.
Usually this involves introspection
on his own thoughts and feelings.
Impressions and Ideas
Perceptions of the Mind
Ideas
Faint Copies
Impressions
Lively originals
Imagination
Sense Experiences
Thoughts and Memories
Emotions
Love; Hate; Anger
Idea of
apple
Impression
of apple
The Outside
World?
Supporting Arguments

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It is impossible to have an idea without first
having had a prior impression
Hume challenges us to find counter examples
Even God is just a complex idea
Blind men can’t imagine colours
Laplanders can’t imagine the taste of wine
Selfish people can’t imagine generosity
Some animals have additional senses hence can
access additional ideas
Simple and Complex Ideas
Complex
Ideas

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Impressions
Golden Mountain
Virtuous Horse
God
We do this by taking simple ideas and:

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Simple
Our imagination seems unlimited in its
powers
However all complex ideas must be
based on on simple ideas we have
previously copied from an impression


Simple
Ideas
Augmenting
Diminishing
Transposing
Compounding
This supports the empiricist doctrine that
“all ideas are ultimately based on sense
experience”.
Critical Comment

Are all impressions more vivid than their ideas?

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Are all ideas more faint than their impressions?

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E.g. Stripes
Hume provides no ‘grammar’ to tell us how to link these
ideas up.

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Ultraviolet; Infrared; gravity
Can you ever conceive of simple ideas on their own
without thinking of other ideas?

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Cocktail conversations
Do all ideas have a prior impression?

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Nightmares or traumatic memories
Is Hume’s account of perception too simplistic?

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Faint impressions when drunk; morning after
embarrassment
watch + pocket; zebra + crossing.
Can we ever compare an impression with an idea in
practice? (Barrier of Ideas)
Can we ever compare impressions with the outside
world? (Barrier of Impressions)
The Missing Shade of Blue

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Hume’s own counter example!
Imagine You had seen every
shade of blue but one
Then all shades of blue were
arranged on a scale from darkest
to lightest
Hume asks if we could imagine
the missing shade without a prior
impression
Hume surprisingly says yes but
“…it’s so singular and obscure an
example it should not alter our
general maxim…”
Comments on the
Missing Shade of Blue

The example is not
“singular and
obscure”.

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Missing shade of red;
missing note on a
scale; missing type of
architecture.
If not based on
impressions the idea
must be innate!
Threatens to
undermine the whole
of Empiricism!

The example is not
insuperable.

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Hume could say that
the missing shade is a
complex idea based on
simpler ideas.
But doesn’t see the
solution because he
thinks colours must
be simple ideas.
Demonstrates Hume’s
rather cavalier
attitude.
The Association of Ideas


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Why does the thought of one idea
lead on to the thought of another?
Ideas don’t come randomly they
follow an order or pattern and are
always related
There are 3 principles of the
association of ideas:

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Resemblance
Contiguity (In time or space)
Cause and Effect
So every idea is always related to
the next for one of these three
reasons
Comments and Criticisms


What is the difference between contiguity and
cause and effect in Hume’s analysis?
Is there really no such thing as a truly random
chain of thought?

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Is the subconscious mind available to us?

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What about people with “Butterfly Brains”?
What about people with dementia or Tourettes’?
(Freud)
Seems incapable of proof or disproof.
 Hume says that even if we can’t see the
connection in people’s thought it will be
apparent to them.

What if we ourselves are not even aware of the
connection?
Hume’s Fork
All Objects of
Human Enquiry
Relations of Ideas
Matters of Fact
“3 x 5 = 1/2 x 30”
Necessary; Analytic; A Priori
Propositions
“My cat has three legs”
Contingent; Synthetic; A Posteriori
Propositions
Comments on Hume’s Fork

Hume confuses An
epistemological
distinction with a
semantic distinction



A Priori  Analytic
A Posteriori  Synthetic
Kant claimed that
there were synthetic a
priori beliefs which
tell us about the
world but aren’t
derived from
experience

E.g. Every event has a
cause.



Hume’s fork itself falls
foul of the distinction.
Is it a matter of fact
or a relation of ideas?
Hume can’t just say
we should disregard
all exceptions as
nonsense.
If he is right
exceptions shouldn’t
even occur. If they
occur at all then his
distinction is
nonsense
Matters of Fact

Many knowledge claims concern unobserved
matters of fact.

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Statements about the future (Physics)
Statements about the past (History)
Statements about far away places (Geography)
Even day to day knowledge claims
The basis of all our reasoning concerning
matters of fact is “cause and effect”
But where does our idea of cause and effect
come from?
An analysis of causes reveal that they have
three features:

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Priority
Contiguity
Necessity
Causation

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We all have an idea of necessary connection but
where does this idea come from?
Is it a ‘matter of fact’ or is it a ‘relation of ideas’?
Is it acquired by experience a posteriori?


No. We have no impression of the ‘necessity’ or ‘power’
transferring between causes and their effects.
Is it acquired a priori by reason?

No. It’s not true by definition that apples must fall to the
ground. Causes don’t resemble effects so we can’t know
a priori what the effects of any cause will be.
The Origin of our Belief in
Causation

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Hume provides a psychological justification for
our belief in necessary connections
Our belief in causes connection is based on
‘custom and habit’
We don’t observe necessary connections, we
only actually observe ‘constant conjunctions’.
But once we see them often enough we develop
an expectation that the future will resemble the
past.
But this belief is actually irrational. It’s just a
fact about human psychology that our brains
work this way. It’s basis is simply “custom and
habit”.
The only reasoning here is the “reason of
animals”.
Comments



Does Hume’s analysis of causation undermine the
whole of science?
Does Hume’s analysis of causation undermine his whole
project?
Is Hume claiming that there is no difference between
causation and correlation?


Is temporal priority the only way to distinguish causes
from their effects?


E.g. Compulsive gamblers; Alcoholics; abusive partners?
Do we need constant conjunction to infer causal
connections?


What about contemporaneous causes?
Is Hume’s psychological account a sufficiently complex
psychology?


E.g. Tiredness and the 10 O’Clock News
E.g. food poisoning or electrocution
How significant is contiguity in leading us to infer
causal connections?
Hume’s Scepticism

After rigorously applying his “fork”, Hume admits that his
position is in many respects a sceptical one

The Outside World:


God:


Is neither true by definition nor observed.
The self:


Impressions come “unbidden into the mind…we know not
from where”. There may be no world out there.
We have no constant impression of a unified self. We are
just a bundle of impressions.
Moral Values:

These aren’t revealed by reason or experience. Just a fact
of psychology that we approve of some acts and disapprove
of others.
Comments on Hume’s
Scepticism

A surprising outcome for an empiricist
philosopher.





“Hume developed empiricism to its logical
conclusion and more or less destroyed it by
doing so” Richard Osborne
Leaves us knowing not very much for
certain.
Descends into Solipsism
Must we accept Representative Realism?
Must we accept foundationalism?