1. Socrates and the Socratic Turn

2. Socrates Not interested in questions about the nature of reality
Instead he asked questions about ‘the state of one’s soul’
What is courage?
What does it mean to be a good person?
What is justice?
What is piety?

3. Socrates II This is called ‘the Socratic Turn’ Examples:
Symbolically: Socrates ‘turning away’ from nature and to the self
First time that the human mind and condition becomes the target of philosophical inquiry
Examples:
No one knowingly does evil
Justice is not ‘might makes right’

4. Euthyphro
Brief Review of Story in context of life and death of Socrates
1st attempt: “Doing what I am doing”
This is an example not a definition
What all examples have in common
And
Having that in common makes them examples

5. Euthyphro II 2nd attempt: “Loved by the gods”
3rd attempt: “Loved by ALL the gods”
Divine command theory

6. Euthyphro Question Does God command it because it is good,
or is it good because he commands it?
Intrinsic vs. relational properties
Male vs. Brother
Weight vs. Mass
Not the way we think loving works
If relational then morality is completely arbitrary
E.G. should God command us to murder children it would be morally permissible to do so

7. Plato
Greek Philosopher

8. Knowledge of the Good
Socrates claimed that the virtuous person is one who knows the Good
It is then of the utmost importance to figure out how one can actually know the Good
This is the project that Plato takes up
His goal is to try and show how knowledge of the Good is possible
But in order to answer that he must first answer the more general question: how do we know anything?

9. What is Knowledge?
I parked my car in the lot, do I know where my car is?
Knowledge requires certainty
Object of knowledge can’t change
If what can be known can’t change, then physical world can’t be an object of knowledge
It is in a constant state of flux (becoming)

10. What is Knowledge? II
So, if we are to have real knowledge it must meet the following requirements
Unchanging
Non-physical
eternal
Plato’s strategy is to look for an area where there is some knowledge already and then try to figure out what is going on there
Geometry/mathematics

11. The Argument from Mathematics
How is it possible that we know that 2+2=4 or that A2+B2=C2
Mathematical truths do not change
2 is prime, and will always be prime
2 is even and will always be even
2 is that the number two?
NO! It is a representation of the number two
Cat is that a cat? No!

12. The Argument from Mathematics II
In the same way, this is not a triangle, it is a representation of one
Triangles and numbers do not exist physically
No one has ever seen the number two
Triangles are made of lines, which are made of points, which have no dimensions
But they MUST exist
For otherwise mathematics would not be about anything and so would be false

13. The Correspondence Theory of Truth
For a sentence to be true is for it to accurately represent reality
So the sentence ‘the cat is on the mat’ will be true if
There is a cat
There is a mat
And the former is on the latter

14. The Argument from Mathematics III
The same is true of mathematical statements
For 2+2=4 to be true there must be
The number two
The number four
They must be related in the way the sentence says
For A2+B2=C2 to be true there must be
Right triangles

15. Theory of the Forms
So, numbers and geometrical shapes exists as non-physical, eternal, and unchanging objects that are the objects of knowledge
We get in touch with these objects via the use of reason
Plato is a rationalist
Knowledge can only be achieved via the use of reason
These non-physical objects are called Forms

16. Theory of the Forms II From the Greek ‘eidos’
Means idea, but not in the way that we use the word
These Ideas exist outside of the mind, outside of time and space
The mind is able to ‘grasp’ these forms
Two more arguments for Forms
Degrees of perfection
One over Many

17. Degrees of Perfection

18. Degrees of Perfection II
How do you know that the triangles are not perfect unless you know what the perfect one is like
And you are able to compare
This, says Plato, is true of everything
You know that some actions are not perfectly just
But how could you know this unless there was Perfect Justice and you knew it?
That is the Form of Justice

19. The Form of Tree
Those are trees

20. One Over Many
The Forms explain why it is that we categorize certain objects as male but not others
There is a Form for every thing that objects have in common
When you see that an object is, say, a desk you are grasping the Form of that object
The objects are said to ‘participate’ in the Form
An object can participate is many Forms at the same time

21. The Beautiful
Human

22. The Divided Line Metaphysics Epistemology The Good Intelligible World
Higher Forms
Reasoning
Intelligible World
Knowledge
Lower Forms
Reasoning
Sensible Obj
Perception
Opinion
Visible World
Images
Imagination