The PreSocratics

1
The Pre-Socratics

• Ancient Greek Philosophy

2
The First Philosophers

• What is the nature of ultimate reality? problem
  of the one and the many
• What is the nature of change?
• How did the universe begin?
• Reject mythology and poetry of Homer, use reason
  and argument
• Ask What and How, not Who (Zeus) and Why
  (angry)

3
Main Pre-Socratic Philosophers

• Thales
• Anaximander
• Anaximenes
• Pythagoras
• Heraclitus
• Parmenides
• Zeno
• Empedocles
• Anaxagoras
• Democritus

4
The Elements and the Opposites

• Traditionally, there are four elements Earth,
  Air, Fire, and Water
• There are also the opposites the hot, the cold,
  the wet, the dry, the sweet, the bitter, and so
  on.

5
Thales

• The ultimate stuff of the universe is water.
  Everything is ultimately made of water.

6
Anaximander

• The ultimate stuff is
• Indefinite (not some definite element)
• Limitless (without bounds)
• Eternal (uncreated)
• Moving (vortex motion)
• Mechanical explanation of how things came into
  being
• Law of compensation (the warring opposites must
  balance out)

7
Anaximenes

• The infinite stuff of Anaximander is Air, not
  some indefinite stuff
• Air is divine and intelligent
• Guides the world order
• Guides humans (principle of life and soul)
• Compression and Dilation explains how air becomes
  other things

8
Pythagoras

• Numbers are the ultimate reality they give form
  to all material things
• Harmony balance of opposites according to ratio
  of numbers (music, health, justice)
• Religion immortality air is divine and
  immortal the soul is impure air that can return
  to divine air after death if purified (through
  contemplation)
• Problem square root of 2 is irrational

9
Heraclitus

• Reality is like fire all things in flux
• All change moves in a cycle (stone, earth, water,
  clouds, air, and back)
• Logos (Fire, God, Divine Reason) goes through all
  things and orders all change
• The best people see the Logos
• Opposites are identical all is one
• War is necessary, good, and just

10
Parmenides

• Change is not real change requires being and
  not-being, but not-being is nothing and not real,
  so change and motion are impossible
• Reality is being what must be the
  characteristics of reality?
• Reality is known through reason not the senses
• Investigating nature now makes no sense

11
Zeno

• Argued that Parmenides is correct
• Paradoxes show that motion is impossible
• Race course
• Achilles and the Tortoise
• Arrow

12
Empedocles

• Ultimate reality is made of 4 elements Earth,
  Air, Fire, and Water
• All things are made of some combination of these
  elements
• Love and hate are the ordering forces in the
  universe (each takes turns controlling the
  universe)
• Doesnt answer Parmenides the things that we see
  are still not real and theres no explanation for
  motion

13
Anaxagoras

• Reality consists of an indefinite number of
  definite elements, not just 4 elements
• Everything has a little bit of everything else in
  it wood has a little bit of every other element
  in it
• So all of the materials that we see are real, but
  he still doesnt answer Parmenides problem of
  motion how can there be change?
• Mind controls and dominates all things

14
Atomists Democritus

• Answers Parmenides reality consists of only
  Atoms and the Void
• The Void has reality (being)
• Atoms are like tiny Parmenidean ones, so what are
  their characteristics?
• Shape and combination of atoms determines the
  qualities of things
• Reason gives true knowledge
• A correct arrangement of atoms in our bodies
  brings happiness