1. Pre-Socratics Philosophers prior to Socrates
Some Contemporaries of Socrates who were not influenced by his teaching
Beginning of Western Philosophy

2. Questions of Pre-Socratics
Is the universe ONE or MANY?
What is the basic SUBSTANCE of the world?
Is CHANGE possible or an illusion?
What is the relationship between Mathematics, Reason and the world?

3. Thales Father of Western Philosophy
Greek – Lived in the town of Miletus in Asia- Minor (modern-day Turkey)
Didn't assume knowledge based on authority or religion
Thoughts based on observation and reflection

4. Thales Basic Ideas of Thales Everything is made of a single element
The basic element is WATER
The earth is floating on water

5. Pythagoras Greek Mathematician
Pythagorean Theorem: The sum of the areas of the two squares on the legs (a) and (b) equals the area of the square on the hypotenuse (c).
Head of a religious cult which was heavily influenced by mathematics
Numbers are the true nature of reality

6. Pythagoras Philosophical Questions Do humans have a soul?
What happens after physical death?
Is there a power or being greater than the Cosmos (universe)?
Is the Cosmos orderly or chaotic? Why?

7. Pythagoras First thinker to use mathematics in philosophy
Believed that the cosmos is saturated with structure (therefore saturated with mathematics)
Intelligent Design – Structure of Cosmos is evidence of an “Intelligence” behind the Cosmos

8. Nature is full of geometrical shapes.
Pythagoras
Nature is full of geometrical shapes.

9. Pythagoras Nature is full patterns and organization.
Daily Sunrise and Sunset
Four Repeating Seasons
Birth – Growth – Death
Ocean Waves and Tides
Flocks of Birds

10. Compare Nature and Man-made things
Pythagoras
Compare Nature and Man-made things

11. Pythagoras The soul survives physical death.
Transmigration of Souls
The soul survives physical death.
The soul moves (transmigration) to a new physical body after death.

12. Xenophanes Questions What is reality? Can humans know reality?
What is God like?
Is there One God or many gods?

13. Xenophanes Reality and Knowledge
“as for certain truth, no man has known it,
Nor shall he know it, neither of the gods
Nor yet of all the things of which I speak...
For all is but a woven web of guesses.”

14. Xenophanes Reality and Knowledge
Reality – There actually exists a truth of reality
Knowledge – Humans are unable to know it with certainty
Contemporary philosophies of Critical Rationalism (Karl Popper) and Critical Realism (Roy Bhaskar) hold similar views.

15. Xenophanes God(s) But if cattle and horses and lions had hands
or could paint with their hands and create works such as men do,
horses like horses and cattle like cattle
also would depict the gods' shapes and make their bodies
of such a sort as the form they themselves have.
...
Ethiopians say that their gods are snub– nosed [σιμούς] and black
Thracians that they are pale and red- haired.

16. Xenophanes
God(s)
Since humans really can't know the gods they have made them up in their own image.
Possibly the first Monotheist in Western Philosophy
Development of the concept of a "one god greatest among gods and men"
God is abstract
God is universal
God is unchanging
God is immobile
God is always present

17. Heraclitus Questions Is there anything that doesn't change?
What are opposites?
What is the primary element of the universe?
What is the principle order of knowledge?

18. Heraclitus Everything is Flux
The only constant thing in the universe is change
“You can't step into the same river twice”
Vocabulary
Flux – constant change

19. Heraclitus
Activity:
Is this mountain trail going UP or DOWN?

20. Heraclitus
Activity:
Is this glass of water half-empty or half- full?

21. Heraclitus
Activity:
Is money Good or Evil?

22. Heraclitus

23. Heraclitus Unity of Opposites The way Up is Down
Half-full is half-empty
Money is Good and Evil
Similar to concept of Yin- Yang

24. Heraclitus Fire is the Primary Element
3 Principle Elements – Fire, Earth and Water
Fire is the Primary Element because it controls and changes the other two
The Cosmic Fire is the center of the cosmos. Human souls come from it and return to it after death.

25. Heraclitus
Logos
“This Logos holds always but humans always prove unable to understand it, both before hearing it and when they have first heard it. For though all things come to be in accordance with this Logos, humans are like the inexperienced when they experience such words and deeds as I set out, distinguishing each in accordance with its nature and saying how it is. But other people fail to notice what they do when awake, just as they forget what they do while asleep.”
“For this reason it is necessary to follow what is common. But although the Logos is common, most people live as if they had their own private understanding.”

26. Heraclitus Logos Principle order of all knowledge and existence
The link between rational discourse and the rational structure of the world.
Logos has an independent existence and is universal
Possibly a divine entity

27. Parmenides Questions What is the nature of reality?
Is change possible?
Can you trust your sensory perceptions?
What is the Logos?

28. Parmenides Discussion: Do Unicorns Exist? What is Existence?
Why? Why not?
What is Existence?
What is Real?

29. Parmenides Do Unicorns Exist?
Parmenides believes that unicorns do exist
“One cannot know that which is not – that which is impossible, nor utter it; for it is the same thing that can be thought, that is.”
To think of something is to think of an idea (i.e. Uncorn)
The IDEA of a unicorn is real.
Therefore unicorns are real in the realm of ideas.

30. Parmenides To think of something means that “something” exists
It is impossible to think of “something” that does not exists because you would have to think of “something” and “not- something” at the same time.
Existence includes more than objects in the physical world.
When you think of “something” you are thinking of an IDEA.
Ideas are real.
Reality includes IDEAS.

31. Parmenides Everything is Eternal
It is impossible for something to come out of nothing.
It is also impossible to for something to become nothing.
Therefore, things are eternal (no beginning and no end).

32. Parmenides Time does not change
If you can think of something that will exist in the future, then it exists in your mind in the present.
If you think of something that existed in the past, then it also exists in your mind in the present.
Therefore, anything that can be thought of has always existed and always will exist.

33. Parmenides Change is an Illusion
If everything that can be thought of is eternal, then the universe is an eternal, single and unchanging entity.
If the universe is and eternal, unchanging and single entity, then CHANGE is impossible.
Opposite view of Heraclitus.
What we perceive as change is just an illusion

34. Parmenides
Perception:
What kind of woman do you see?

35. Parmenides Perception:
Paramenides said that we can't trust our sensory perception (sight, hearing, touch...) because they can be deceived.

36. Parmenides Logos Truth cannot be known though sensory perception.
Truth can only be know through Logos.
Logos = Reason

37. Zeno of Elea Paramenides' Student
Wrote many paradoxes to prove Paramenides' premise that change is an illusion

39. Zeno of Elea Achilles and the Tortoise 1/2
In order to reach the point where the Tortoise started Achilles must first pass the half-way point.

40. Zeno of Elea Achilles and the Tortoise 1/2
By the time Achilles reaches the point where the tortoise was the tortoise will have moved on from that point.
1/2
When the Tortoise moves that will create a new half-way point that Achilles must also cross.

41. Zeno of Elea Achilles and the Tortoise 1/2
Each time Achilles reaches the point where the tortoise was he will have a new half-way point to cross.

42. Zeno of Elea Achilles and the Tortoise 1/2
Since the Tortoise is constantly moving his movement will produce an infinite number to half-way points that Achilles must cross before passing the Tortoise.
Therefore, Achilles will never pass the Tortoise.

43. Zeno of Elea Arrow Paradox
At any point in time an arrow can only occupy one position and is therefore motionless.
At every point in time the arrow is motionless.
If the arrow is motionless at every point in time then it does not move. Movement is an illusion.

44. Zeno of Elea Zeno's Paradoxes
Show that a good and logical argument can lead to a false conclusion.
Therefore, Logic seems to be flawed

45. Democritus Questions What is the basic unit of matter?
What is the soul?
Does everything have a cause?

46. Democritus Atoms Void Atoms The cosmos is made up of Atoms and Void
Atoms = Indivisible particles of matter
Void = The space between atoms
Atoms
Void

47. Democritus Atoms Void Problem of the Void
A VOID is the absence of something.
Therefore, a VOID is nothing.
If a void is nothing then how can it be real? How can a void exist if it is nothing?
Atoms
Void

48. Democritus The Soul The soul is a material aspect of the body
Therefore, it cannot be separated from the body.

49. Democritus Knowledge The knowledge of truth is difficult.
Perception through the senses is subjective.
We can only interpret the sense data through the intellect and grasp the truth.