Sophists (Protagoras, Gorgias, etc.)
  - "Man is the measure of all things"
    - human knowledge matters, not ultimate truth (which may be unknowable 
anyway)
    - truth for humans is relative to the individual, his experiences, his 
culture
    - to understand a belief, understand the believer
  - focus of questions shifts from the cosmos (ontology) to human knowledge 
(epistemology)
  - persuasion and rhetoric are key skills (to be taught professionally!), 
because any idea's merit depends only on getting others to believe it
  - beliefs are words, so can be changed using words
  - Today's Sophists: lawyers, political "spin doctors", public relations 
consultants...


Socrates (470-399 BC)
  - like Sophists, in examining human knowledge; UNlike, in his belief that 
truth exists beyond mere belief and opinion
  - oracle indicated wisdom in his ignorance
  - call something "beautiful" but also say WHY
    - "The unexamined life is not worth living"
    - Knowing right automatically means doing right
  - inductive definition: consider example after example to arrive at a 
concept's "essence"
    - an agreed-to definition in words ("Knowledge" means "Knowing what you are 
talking about")
    - note: NOT an abstraction as Plato would favor, but a precise definition in 
a particular community
    - "Socratic method": ask questions to let knowledge emerge (mainly knowledge 
of virtue: how one SHOULD live)
  - execution for corrupting the youth, impiety, introducing new gods 
(Socrates's "daemon"?)


Being
  - Parmenides:
knowledge is permanent, so change is an illusion
  - Democritus:
atoms are unchanging, eternal, and make up every object in the world (including 
body AND soul)
  - Pythagoras:
numbers are eternal, perfect, the realm to which the soul will return when the 
body dies
  - Dionysian mysticism: cyclical "transmigration" of eternal souls into new 
bodies

Becoming
  - Heraclitus:
empirical world is changing, so permanence is an illusion
  - Pythagoras:
empirical world is imperfect, degrading; the physical body is a prison for the 
soul
  - Democritus:
empirical world's objects will disintegrate (though atoms will remain when no 
longer arranged into form of body)
  - Democritean materialism: determinism, reductionism, elementism


Plato (427-347 BC)
  - accepts Pythagorean dualism of soul and body, and of earthly and spiritual 
realms
  - accepts Pythagorean version of transmigration of souls
  - transforms Pythagorean claim about abstract numbers and their effects in the 
empirical world into a claim about abstract forms in general and their 
appearance to our bodily senses as the familiar objects of the empirical world
  - provides an account of WHAT we know, along with an account of HOW we know...

Plato's ontology and epistemology

  - Theory Of Forms:
we see the interaction of abstract form with matter, which gives an imperfect 
rendering of the form

  - The Divided Line
world of appearances:
imagining about images; believing about objects
world of knowledge:
thinking about mathematical relationships; knowing about forms
"The Good" is the ultimate form, the form of the forms

  - The Allegory Of The Cave: a story of the Divided Line
  - Reminiscence Theory Of Knowledge (nativist & rationalist)
  - The Soul: rational (immortal), courageous/emotional, appetitive (mortal and 
shared with animals; to be suppressed and controlled)


Aristotle (384-322 BC)
  - student of Plato; tutor of Alexander The Great
  - looks at the empirical world, while Plato looks to the abstract
  - study nature to find essences on Earth
  - Plato isn't conducive to science; Aristotle is (though not quite a 
scientist)

- Three Types of Soul - higher types subsume lower types:
    - vegetative (nutritive functions) - found in plants
    - sensitive (perception, experience, memory) - found in animals
    - rational (reason) - found in humans; immortal, but impersonal: same in 
everyone!

  - Four levels of sense or reason
    - five senses
    - common sense
    - passive reason
    - active reason

  - Perception based on movement in different media
    - errors introduced at level of common sense or reason

  - Memory: Recall is based on principles of association
    - similarity
    - contrast
    - contiguity (and frequency)

  - Four Causes (or, Reasons Why Things Are What They Are)
    - efficient
    - material
    - formal
    - final