Knowledge and Reality A

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Knowledge and Reality A

• Lecture Three Justification

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Last Week

• So, weve tried to analyse knowledge
• Agent S knows that p iff
• (i) p is true
• (ii) S believes that p is true.
• (iii) S is justified in believing that p is true.
• Time to set aside whether this is successful.
• Lets look more at one of those criteria.

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Last Week

• So, weve tried to analyse knowledge
• Agent S knows that p iff
• (i) p is true
• (ii) S believes that p is true.
• (iii) S is justified in believing that p is true.
• Time to set aside whether this is successful.
• Lets look more at one of those criterion.

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This Week

• Problems for justification come from a regress
  argument.
• It is sometimes called Agrippas Trilemma after
  the ancient Greek skeptic Agrippa.

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The Regress Argument

• I know my friend is in Sweden.
• How do you know that?
• He called me from there yesterday.
• How do you know it was him?
• It sounded like him.
• How do you know that sounding like him indicates
  it is him.
• Because I know he doesnt have a twin.
• How do you know that?
• Because Ive known him all my life, and never
  met his twin nor heard him mentioned. Hed have
  to have kept him in a basement of something.
• How do you know he doesnt do that?
• I dont think he has a basement as Ive never
  seen it.
• And so on.

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The Regress Argument

• Problems for justification come from a regress
  argument.
• It is sometimes called Agrippas Trilemma after
  the ancient Greek skeptic Agrippa.
• So its a bit like a child who continually asks
  Why? a game Im sure youve all played (on
  one side or another).

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The Regress Argument

• What could happen now?
• Either
• It goes on forever.

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The Regress Argument

• What could happen now?
• Either
• It goes on forever.
• Some of the beliefs dont need justifying on the
  grounds of other beliefs and we just hit rock
  bottom.

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The Regress Argument

• What could happen now?
• Either
• It goes on forever.
• Some of the beliefs dont need justifying on the
  grounds of other beliefs and we just hit rock
  bottom.
• Some of the beliefs justify themselves.

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The Regress Argument

• What could happen now?
• Either
• It goes on forever.
• Some of the beliefs dont need justifying on the
  grounds of other beliefs and we just hit rock
  bottom.
• Some of the beliefs justify themselves.

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The Regress Argument

• This option (infinitism) we will look at only
  briefly.
• We end up with an infinite regress.
• We have an infinite number of beliefs, each one
  justified by another one. The regress never ends.
• The problem is that surely this is demonstrably
  false I never had time to learn an infinite
  number of things so my mind cant work like that.
• So I dont know anything!

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The Regress Argument

• What could happen now?
• Either
• It goes on forever.
• Some of the beliefs dont need justifying on the
  grounds of other beliefs and we just hit rock
  bottom.
• Some of the beliefs justify themselves.

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Foundationalism

• This option is the Foundationalist response.
• The Foundationalist believes that we need a core
  set of beliefs, a foundation, that all our other
  beliefs are built upon.
• Call these beliefs, those that are not inferred
  from other beliefs, basic beliefs.

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Foundationalism

• But we have to be careful here.
• As a matter of descriptive fact there are
  obviously people who take certain beliefs as
  basic, and then build up from there.
• But that wont always get us what we want.

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Foundationalism

• Example Crazy dude.
• There might be someone who believes that
  poisonous gas will seep through the windows and
  kill them.
• Being crazy they might take that belief as basic.
• Example The lazy hippy.
• Someone might take as basic that they need not
  work for a living and can live off of the dole.
• They can build up a structure out of that.

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Foundationalism

• In each case the people have a foundationalist
  belief structure.
• The basic belief justifies the beliefs that stem
  from it.

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Foundationalism

• In each case the people have a foundationalist
  belief structure.
• The basic belief justifies the beliefs that stem
  from it.
• But nonetheless we dont want to say they are
  justified in those further beliefs.
• Just that they would be justified if the basis
  were justified.

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Foundationalism

• So there are people with basic beliefs.
• But we want an answer to the trilemma where we
  are justified in knowing things.
• We want basic beliefs that are themselves
  justified, and can act as justification for the
  beliefs we build upon them.
• Call such beliefs properly basic.

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Foundationalism

• So a properly basic belief is justified (in a way
  that crazy and lazy hippy beliefs are not).
• But its not justified on the basis of any other
  belief.
• Its not inferred from any other belief.
• So non-basic beliefs are inferentially justified.
• Basic beliefs are non-inferentially justified.

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Classical Foundationalism

• The problem is what counts as a properly basic
  belief.
• Classical foundationalism says that we need to
  find a belief of which we are absolutely certain
  of.
• If we are absolutely certain of it, if it cannot
  be false, then it is justified without relying on
  any other belief.
• But what kind of beliefs can we be absolutely
  certain of?
• I am in pain? I exist? I have a sensory
  impression of first years?
• And do those beliefs justify the rest of my
  beliefs?
• Is Ive been shot justified by I am in pain?
• Does I have a sensory impression of first years
  justify There are first years in front of me?

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Other Foundationalisms?

• Other variations exist that arent classical and
  think a properly basic belief neednt be certain.
• I leave you to look at them.

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The Regress Argument

• What could happen now?
• Either
• It goes on forever.
• Some of the beliefs dont need justifying on the
  grounds of other beliefs and we just hit rock
  bottom.
• Some of the beliefs justify themselves.

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Coherentism

• A naïve version makes this circular.

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Coherentism

• A naïve version makes this circular.
• That wont work!
• But a more sophisticated theory is coherentism.

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Linear/Non-linear Justification

• But perhaps the problem is with thinking
  justification is linear.
• That each belief is justified by one other
  belief, or a small handful of other beliefs.
• Which are in turn justified by a one/a handful of
  beliefs.
• Coherentists think that justification is
  non-linear.
• Every belief in your system is partially
  justified by every other belief in your system

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Linear/Non-linear Justification

• But perhaps the problem is with thinking
  justification is linear.
• That each belief is justified by one other
  belief, or a small handful of other beliefs.
• Which are in turn justified by a one/a handful of
  beliefs.
• Coherentists think that justification is
  non-linear.
• Every belief in your system is partially
  justified by every other belief in your system
• So to determine whether a belief is justified we
  have to look at the system as a whole.

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Linear/Non-Linear Justification

• Here are some analogies to help you get a better
  grip on the notion.
• Foundationalism thinks there are foundational
  beliefs like the foundations of a house.
• On top of these beliefs are built non-basic
  beliefs like the walls and rooms of a house.

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Linear/Non-Linear Justification

• Where Foundationalists see comparisons with a
  house
• Coherentists see a comparison with a wigwam.
• No one piece of the structure is more important
  to holding it up than any other.

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Linear/Non-linear Justification

• Or another analogy.
• A crossword.
• As you fill in a crossword, your answers in one
  place can make you more confident of your answers
  elsewhere.
• Similarly for Coherentist belief.
• One belief can make you more confident of
  (justify!) the other beliefs.

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Linear/Non-linear Justification

• So for the (caricature) Coherentist there arent
  any basic beliefs. Everything is (partially)
  justified by another belief.
• So for the coherentist justification is analysed
  thus
• Agent S justifiably believes p iff Ss belief
  system is coherent and S believes p.

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Example

• So I am justified in believing there an audience
  of first years in front of me as it coheres with
  the rest of my belief structure.
• I am a lecturer.
• I am giving a lecture.
• First year students attend lectures.

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Example

• But I would not be justified in believing that
  famous comedian Frankie Howerd is President of
  the USA as it doesnt cohere with other beliefs
• Frankie Howerd is a comedian, not a politician.
• Frankie Howerd is British.
• Frankie Howerd is dead.

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Problems for Coherentism

• First problem What exactly is coherence?
• What conditions are there for a set of beliefs
  being coherent?
• In other words, what analysis can we give of
  coherence?

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Problems for Coherentism

• You might think coherence has something to do
  with consistency.
• Two propositions are consistent iff it is
  possible that their conjunction be true.
• Example 224 and 235.
• Example Me being a lecturer and the moon being
  made of cheese.
• Example of inconsistency Charles Lindbergh as
  the first solo Transatlantic pilot and Charles
  Fern as the first solo Transatlantic pilot.
• But imagine you believed just those things! You
  wouldnt be justified in believing them!

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Problems for Coherentism

• Problem Two Competing coherent systems.
• Example The existence of fossils.
• One coherent system takes the existence of the
  fossils along with evolution explaining their
  being there.
• But the are other coherent, if not justified,
  explanations.

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Problems for Coherentism

• Late at night a group of liberal Democrats led
  by Obama carefully insert the fossils into the
  ground to persuade us of the truth of evolution
• before ending the evening drinking the blood of
  children and engaging in a round of terrorist
  fist jabs.

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Problems for Coherentism

• The later system is coherent, but surely not
  justified.
• (whatever your view on Creationism, that
  justification would be nuts)
• Indeed, for just about any belief we can imagine
  it contained within a coherent system.
• So, given that any belief could be justified,
  wouldnt it be irrational to think your belief
  was justified and true, whereas everyone else was
  wrong?

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Problems for Coherentism

• Essentially, we seem to lose justification as a
  guide to truth.
• Whilst we admit that sometimes justified beliefs
  are wrong, surely normally they take us to true
  beliefs.
• But now any belief, even a false belief, can be
  justified.
• That normative element of justification is lost.

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Next Lecture

• Skills How the heck to find out about these
  theories?