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Zeno

Epicurus

Averroes

Anaximander

Pythagoras

Anaxagoras

Hypatia

Parmenides

Eschines

Alcibiades

Xenophon

Alexander

Socrates

Heraclitus

Plato

Aristotle

Diogenes

Euclid

Zoroaster

Ptolemy

Raphael

Classical Greek Philosophy

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�

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Socrates�470-399 BC

  • Divided philosophy into 2 groups
    • Pre-Socratics
    • After were based upon his ethics and methods
    • Philosophers versus Sophists
  • Believed in a single, all powerful God
  • Used dialectics (Socratic Method) to find ultimate truth

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Socrates

  • Taken to trial (Apology)
  • Convicted—he did not put on a defense
  • Sentenced to death
  • Drank hemlock (Phaedo)

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“The unexamined life is not worth living.”

– Socrates

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Plato� 427-347 BC

  • Student of Socrates
  • Born an aristocrat
  • Founded the Academy
    • First university
    • Purpose-thinking about deeper meanings
  • Wrote dialogues of Socrates, his own political theory and works of ethics

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Plato

  • Forms or Ideas
    • Continuation of Socrates’ "ultimate nature"
    • Essence of something lies in the Form
    • Form has perfection
      • "Ideals" comes from "Idea" = "Form"
    • Immaterial things also had Forms
      • For instance: Our remembrance of the Form of beauty allows us to see beauty in other things

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One of Plato’s critics said: “I see particular horses, but not horseness.”

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Plato answered: “That is because you have eyes but no intelligence.”

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Plato

  • Spiritual is more real than the physical (Timaeus)
    • Physical changes, Form is eternal
    • Truth cannot be perceived by the senses
    • Perfection is only found in the Forms
  • At death, the soul migrates to the World of Pure Form
  • What is the concept of a perfect God?

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Plato

  • The Republic
    • Idea of the perfect society
    • “What is the nature of reality?”
    • Philosophers emerging from the cave

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Plato

  • Mathematics
    • Supported Pythagorean school
    • Math is the organizing rules for the Forms which combine in various geometric shapes to create all things

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  • Sign on the door of the Academy

“Let no one ignorant of geometry enter here”

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Aristotle�384-322 BC

  • Son of a physician
  • Born in Macedonia
  • Attended the Academy
  • Became Plato’s foremost student
  • Left the Academy when Plato died
  • Founded the Lyceum in Athens
    • More focused in natural science

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Aristotle

  • Forms
    • Some Forms have qualities and quantities that are not fixed (and therefore not "perfect")
      • Colors or measurements
    • Forms can be perceived from the object itself by observation and from many others that have similar Forms to develop the nature of the Form of that thing
    • True nature is understood by observation
    • Classification of the sciences

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Aristotle

  • Wrote on physics
    • Universe is eternal, finite and spherical
    • Earth is center of the universe
    • World composed of 4 elements (earth, fire, water, air)
    • Heavens composed of aether
    • 4 elements affected by qualities (dry, cold, wet, hot)
    • Real objects are composites of Form and matter
      • Plato did not value matter
      • Note Aristotle’s thinking—spirit and body

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Aristotle

  • Four Causal Questions (Physics)
    • Material Question (What is it made of?)
    • Efficient Question (What caused it?)
    • Formal Question (What is its Form or essence?)
    • Final Question (What is its final end or purpose?)

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Aristotle' Influence

  • Taught Alexander the great
    • Therefore was mistrusted by Athenians
  • Basis of latter medieval science and religion
    • Ideas had internal consistency
    • Ideas were adopted by St. Thomas Aquinas and the Catholic Church

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Summary –�Greek Legacy on Learning

  • The world is rational (i.e., science)
  • The world can be understood by examining the fundamental
  • Truth is unchanging
  • Science is available to all
  • How to learn systematically
  • Rules of logic

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“My advice is to get married: if you find a good wife you’ll be happy; if not you’ll become a philosopher.”

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Deep Philosophy

From Socrates

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“The only useful knowledge is that which betters us.”

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- Socrates

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Socrates

  • Socratic Method
    • Posed questions and then questioned the answers
    • Searched for the ultimate nature of qualities
      • What is Duty?
      • What is Truth?
      • What is Evil?

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Socrates taught:

Happiness is the consequence not of physical or external circumstances, of wealth or power or reputation, but of living a life that is good for the soul. Yet to live a genuinely good life, one must know what is the nature and essence of the good.

— Richard Tarnas in The Passion of the Western Mind

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“Good people do not need laws to tell them to act responsibly, while bad people will find a way around the laws.”

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Plato

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Thank You