The Neoplatonism of Plotinus A'D' 205270

1
The Neoplatonism of Plotinus (A.D. 205-270)

• He accepted Platos two-realms view of reality
• He identified ultimate reality with the One, a
  god who is
• transcendent and impersonal
• indefinable and indescribable
• apprehended by a mystical experience of unity

2
St. Augustine (A.D. 354-430) Christian Themes
and Neoplatonism

• He identifies the ground of all reality and
  knowledge with the personal God of Christianity
• He replaces the Greek notion of crafting a world
  from pre-existing materials with the Christian
  doctrine of Creation ex nihilo (out of nothing)
• He sees Christ as God in a material and human
  form

3
Sextus Empiricus (2nd-3rd century A.D.)Pyrrhonic
Skepticism

• Knowledge is possible only if we have good
  grounds for believing that the way the world
  seems to us is the way it is
• But we never do, since
• we never directly perceive things as they are
• the senses cannot tell us how accurate they are
• for every argument, there is an equal and
  opposite argument
• So in all cases we should suspend judgment

4
St. Augustines Refutation of Skepticism

• By the principle of noncontradiction we can know
  many things with certainty
• The very act of doubting proves our own existence
  as a doubter
• Sense perception gives us rudimentary knowledge
  so long as we stick to only what is given in the
  appearances themselves

5
Hypatia (c. 370-415 A.D.)

• The last head of the great library of Alexandria
• Worked to improve the accuracy of Ptolemys
  earth-centered astronomy
• The first to attempt completeness proofs in
  mathematics
• Saw mathematics and astronomy as ways to check
  metaphysical and epistemological conclusions

6
St. Thomas Aquinas (1225-1274) and the Middle Ages

• He held that philosophy (based on reason) could
  support but not entirely explain theology (based
  on faith and revelation)
• He agreed with Aristotles matter plus form
  metaphysics, his four causes, and his doctrine of
  change.
• He went beyond Aristotle
• essence does not equal existence
• souls are created directly by God