Plato

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• Plato
• and the Republic

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History of Philosophy in Brief 5th Century BC
Peloponnesian War

• Good guys The Sophists
• Heraclitus all is in flux
• Protagoras values are relative advised
  Pericles
• Gorgias in praise of Helen
• Antiphon rhetorician leader of oligarchic coup
• Thrasymachus justice is interest of the
  stronger
• - taught philosophy as a technical skill
• Bad guy Socrates
• - taught philosophy as a way of life
• Result Followers of Good guys kill bad guy
  (Socrates)

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History of Greek Philosophy, 5th Century BC

• Sophist Socrates

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Teachings of the sophists relevant to the
Republic

• 1. Everything is in flux (Heraclitus).
• 2. Justice is nothing other than the interest of
  the stronger (Thuc., Hist. Thrasymachus, Rep.
  I)
• 3. Man is the measure of all things
  (Protagoras), i.e., values not real, but relative
  and a matter of opinion.
• 4. A cynical view of human nature.
• 5. Sophists taught how to make the weaker
  argument the stronger, i.e., philosophy is a
  technical skill that helps you in your career,
  for example, as a lawyer.

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Students of Sophists relevant to Republic

• Thucydides (460-395 BC)
• student of Antiphon
• put Sophistic reasoning in mouths of Athenians
  Spartans in Melian Dialogue (v.89) End of
  Platea
• Justice depends on the balance of power. In fact
  the stronger can do whatever they have the power
  to do, and the weak must accept whatever the
  stronger does (Melian dialogue)
• Melian Dialogue presents Thrasymachus teaching
  on justice 20 years before Republic

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Students of Sophists relevant to Republic (cont.)

• Thucydides represents Athenians Spartans
  negatively by associating them with Sophistic
  teaching
• But Thucydides also expresses Sophistic cynicism
  
• Human natureshowed itselfas something
  incapable of controlling passion, insubordinate
  to the idea of justice, the enemy to anything
  superior to itself (Civil War in Corcyra,
  iii.84).
• Thuc. a kind of ancient Hobbes, regarded virtue
  as unattainable or illusory.

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Students of Sophists relevant to Republic (cont.)

• Thucydides cynicism about human nature is a
  pessimistic conclusion drawn from the
  Peloponnesian War, which devastated Greece and
  reduced many to barbarism.
• Whether we regard Thucydides a Sophist is
  unimportant. What is important for Plato is that
  he expressed such cynicism about human nature

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History of Philosophy in Brief 4th Century BC
Aftermath of Peloponnesian War

• Influence of Sophists declines
• Influence of Socrates students, Plato
  Aristotle rises
• Plato writes dialogues criticizing Sophists,
  e.g., Republic
• Now, Socrates The good guy
• Sophists The bad guys

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History of Greek Philosophy, 4th Century BC

• Socrates Sophist

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Socrates

• Taught philosophy as a way of life
• The unexamined life is not worth living.

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Platos goals

• To refute and destroy reputation of Sophists
• To refute cynicism about human nature expressed
  by Thrasymachus Thucydides
• To advance optimistic model of human nature
• In difficult times, we can rely on human dignity
  and act justly despite how others may be behaving

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Soul as chariot (discussed in Plato, Phaedrus)
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• Clytemnestra kills Cassandra (scene from the
  Agamemnon of Aeschylus)

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Scene from Verdis La Traviata
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Sign at entrance of Academy
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Fig. 1 The Platonic Solids
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Role of study of geometry mathematics

• 1) It transfers us from the material to the
  intellectual, and so frees us from domination of
  appetites and emotions.
• 2) It proves that even human reason is
  non-arbitrary, not relative, so that justice, for
  Plato, becomes a constructible, almost
  geometrical concept.

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Fig. 3 Platos Model of the Soul
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Fig. 4 Platos Model of the Guardian State
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Ostracism

• Ostracon recording vote to exile Themistocles