David Hume

David Hume (1711 ~ 1776)

Edinburgh, Scotland, Great Britain


  • Two types of perceptions
    • Impressions: Immediate Sensation
    • Ideas: Recollection of Impressions


  • What determines what we do is not Reason but Sentiments (Feeling).

Baruch Spinoza

Baruch Spinoza (1632 ~1677)

Amsterdam, Dutch


  • Pantheism
    • God is all. All is in God.
  • Substance
    • There is only ONE substance (God/Nature)
    • Attributes
      • Humans recognize two of many God’s qualities or manifestations: Thought and Extension
    • Modes
      • The various phenomena of the world are modes of two attributes of God/Nature.


  • Human Life is subject to the universal laws of nature.


St. Thomas Aquinas

St. Thomas Aquinas (1225 ~ 1274)

Born in Roccasecca, Sicily


  • Universals are real (- realists -), exist independently of any individual object
  • Matter makes different one object from another. But they contain the universal idea.
  • The World (Nature) is a union of universals (forms) and matter.
  • God created the world out of nothing; God was the cause of everything.
    • Creation did not happen at one time. Creation is going on all the time; God continually brings ideas and matter together to produce new objects.


  • There is no conflict between Reason and Christianity.
  • Reason and Theology reinforce each other.


  • Bible teaches us how God wants us to live.
  • God had also given us a conscience (reason), so man can distinguish between right and wrong.

St. Augustine

born in Thagaste, Numidia (modern-day Souk Ahras, Algeria)
354 ~ 430


  • Try to reconcile Christianity with Greek philosophy
  • Ideas” of Plato and “Forms” of Aristotle became God


  • Dualism: God and Evil, Light and Darkness, Spirit and Matter


  • Everything is God’s creation and must follow His laws and will.
  • Matter was created by God out of nothing (void) according to the ideas and forms in God’s mind.


  • God’s creation is only good.
  • Evil comes from mankind’s disobedience