Plato on Knowledge

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Plato on Knowledge
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Plato

• 429-347 BC
• Student of Socrates (469-399)
• Teacher of Aristotle (384-322)
• Founded Academy
• Wrote Dialogues
• Theaetetus
• Republic
• Meno

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Theaetetus

• A late treatment of knowledge
• Dismisses two possibilities for knowledge
• Perception
• True belief
• Proposes True Belief with an Account
• To know X is to truly believe X and to have an
  account of X
• But what is an account? Justification for the
  belief?

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Theaetetus

• First possibility an account is an analysis of
  how X is composed of simpler parts
• So no simple thing can be known?
• Reject this idea

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Theaetetus

• Second possibility an account is a catalogue of
  the component parts
• But you can list the parts of a chariot without
  having an understanding of the chariot itself.
• Reject this idea

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Theaetetus

• Third possibility an account is an
  identification of the distinguishing
  characteristic
• To know X about the sun is for X to be a true
  belief and you can identify the sun as, say, the
  brightest object in the sky
• But this means there is always something else to
  know before you can know any X
• Reject this idea

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Theaetetus

• All possibilities are eliminated.
• Aporia again?
• Plato has another theory from previous dialogues

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The Theory of the Forms

• There is a realm of real things that are both
  non-physical and non-mental
• Things in this realm are the Forms (ideas in
  Greek) of things in the physical realm
• Things in the physical realm are what they are
  because they are in some way connected to their
  Forms
• We can know things only through acquaintance
  with their Forms

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The Theory of the Forms

• Forms explain the possibility of general terms
• We can call many things by one name
• All things which are dogs we can call a dog.
• There must be something which is
• Common to all things called by a general term
• Distinctive of all those things
• This thing is
• Not physical not all dogs have any physical
  trait
• Recognisable by us but not by our senses

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The Theory of the Forms

• Forms explain the possibility of judgement
• All judgement is a type of comparing
• This is a dog means I am comparing this to
  some standard of dogginess
• The standard cant be another dog else I have
  to first judge that that is a dog, and so on
• The standard cant be my idea of a dog it is
  the idea of a dog only because it is judged to
  represent dogs accurately. So I still need to
  judge its dogginess and so on.

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The Theory of the Forms

• Forms explain the possibility of judgement
• The standard of dog cant be physical or mental
• It is metaphysical
• It is that in virtue of which
• All things properly called dog are properly so
  called
• Only things properly called dog are properly so
  called
• We call it the Form of dog, or dog-in-itself,

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The Theory of the Forms

• How do Forms relate to their particulars?
• Transcendence there is far more to the Forms
  than the particular things which fall under them
• Immanence the Forms are present in their
  particulars, but not in a way that we can
  perceive through our senses

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The Theory of the Forms

• How do we come to know of them?
• Not by our external senses (perception)
• Not by our internal sense (awareness)
• But by intellectual perception or awareness of
  the understanding
• (Whatever those might be)

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The Theory of the Forms

• Who is capable of knowing them?
• We are all able to use the term dog correctly,
• So we are all intellectually aware of the Form
  of Dog
• Dog is the Form of a mundane thing it is a
  lower Form
• Higher Forms are of things such as Triangle,
  Courage, Equal, Noble,
• Only those trained as intellectuals can perceive
  these in their understanding

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How we Know

• How do we come to know the higher Forms?
• Plato gives an example in the Meno
• A slave is taught to double a square
• Slave thinks he knows but gives the wrong answer
  at first before Socrates begins to question him
• This also shows the value of elenchus
• Socrates then gets the slave to give the right
  answer
• Since the slave only answered questions, he must
  have known how to double a square already

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The Allegory of the Cave

• What is the difference between how normal people
  see the world and how philosophers see it?

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The Objects of Knowledge

• Only the Forms are objects of real knowledge
• They are permanent, unchanging, always true
• What is learnt through the senses is opinion
• It is impermanent, changeable, sometimes true and
  sometimes not
• Plato is contradicted by Aristotle, as we shall
  see