1. Lecture 5: Plato

2. Today’s Lecture In Today’s lecture we will:
Recap what we learned about Plato’s theory of reality in lecture
Clarify Plato’s argument for the existence of eternal forms
Investigate Plato’s ‘Divided Line’
Investigate Plato’s allegory of the cave
Consider some criticisms of Plato’s theory of reality
Briefly Consider Some alternatives
Conclude our investigation into Plato’s theory of reality
Today’s Lecture

3. Recap

4. Topic Recap The question of reality (Metaphysics) What is reality?
What are things made of?
What is the ultimate?
What is it that everything depends on for its existence?
What is really real?
How do we distinguish between what is real and what is mere illusion?
The problem of the one and the many
What is the ultimate reality (the One)?
How is everything else (the Many) related to the One?
Topic Recap

5. Topic Recap Ontological options
Ontology is the study of what exists, what is real etc.
Ontology is a branch of metaphysics.
Most theories of reality maintain one of the following ontological beliefs:
Monism
The belief that reality is composed of one thing.
Dualism
The belief that reality is composed of two things.
Pluralism
The belief that reality is composed of many things.
Nihilism
The view that nothing exists
Topic Recap

6. Topic Recap In answer to the question; what is reality? Plato answers:
Reality is composed of Two distinct worlds:
The Space-Time world of BECOMING (the world according to the senses)
The transcendent world of BEING (a world not experienced by the five senses but still related to the world of Becoming)
Objects in each world exhibits the following characteristics:
Objective
Transcendent
Eternal
Intelligible
Archetypal
Perfect
Transcendent world of BEING
Space-Time world of BECOMING
Subjective
Spatiotemporal
Changeable
Sensible
Copied
Imperfect
Topic Recap

7. Topic Recap In answer to the question; what is reality? Plato answers:
The space-time world of Becoming is full of Sensible objects (we can sense them)
The transcendent world of Being is furnished with Forms (or Ideas) which impart essence onto worldly objects
Forms are related to objects by:
The extent something reflects the True form
The extent something participates in the True form
Plato divides between Higher Forms (things without physical manifestation) and Lower Forms (things that manifest physically)
Form (Idea) chairs
Transcendent world of BEING
Space-Time world of BECOMING
Topic Recap

8. ...some clarification

9. Clarification of Plato’s Reasoning
Clarification of Plato’s reasoning (the problem of universals)
Heraclitus:
There is no One Unchanging Thing except change; the world undergoes constant changes (Heraclitus)
The Problem:
Plato: Option 1 leads to impossible conclusions (we could not know or discuss anything). But we do know some things and talk about them.
Plato’s Assumption:
There must be One Unchanging Thing or knowledge and discussion (language) would be impossible.
Plato’s Conclusion:
What is this One? Transcendent, eternal , unchanging Forms in the world of Being
Clarification of Plato’s Reasoning

10. The Divided Line

11. Plato’s Divided Line D C B A Epistemology (Thought) Metaphysics
(Objects) D C B A
Higher Forms
Understanding
Being (Intelligible World)
Knowledge
Mathematical Forms
Reason
Sensible Objects
Perception
Opinion
Becoming
(Visible World)
Images
Imagination
Plato’s Divided Line

12. The Allegory of the Cave

13. Plato’s Cave The Good Higher Forms Mathematical Forms Lower Forms
Hierarchy of Plato’s Theory of Reality
Higher Forms
Mathematical Forms
Lower Forms
Sensible Objects
Images
The Good
The Form of the Good is the ultimate Form and the source of all knowledge and existence
Each being is derived from the next being up
Plato’s Cave

14. Plato’s Cave SUN In VISIBLE WORLD By its LIGHT Cause of SIGHT
And existence of objects and sight
GOOD In
INTELLIGIBLE WORLD
By its
TRUTH
Cause of
KNOWLEDGE
And existence of objects of knowledge (Forms)
Analogous to
Plato’s Cave
(Textbook, P. 69)

15. Plato’s Cave

16. Criticisms of Plato

17. But! Plato does not give us a clear explanation.
Some objections that were raised in regards to Plato’s theory of reality:
What is the relationship between Forms and objects?
For example, if I invent something is a new form created?
Possible answer: Forms do not come into or out of existence (they are eternal) so when we ‘invent’ something we are merely copying a Form which already existed
But! Plato does not give us a clear explanation.
Do we really need something like the forms to explain how we recognize a chair as a chair?
For example, we are taught what is and isn’t a chair; different cultures have different understandings of what different things are.
Isn’t there a simpler way to explain how we can know the essence of an object?
Ockham’s Razor (p.77): “Entities are not to be multiplied without necessity”
Criticisms of Plato

18. Criticisms of Plato The ‘Third-Man- Argument
Aristotle raises the follow problem:
To explain the similarities between Person 1 and 2 we need a third person
Criticisms of Plato

19. Criticisms of Plato The ‘Third-Man- Argument
Aristotle raises the follow problem:
But to explain the relationship between these three we need a fourth...
... And fifth
And so on...
Criticisms of Plato

20. The Problem of Separation
Aristotle further criticizes Plato on the following grounds:
It is unclear in Plato’s theory of reality how the world of BEING relates to and influences the world of BECOMING
Transcendent world of BEING
Form (Idea) chairs
Chorismos (Separation)
Space-Time world of BECOMING
The Problem of Separation

21. Alternatives to Plato

22. Realism Alternative 1: Realism
“The doctrine that Forms, or essences, possess objective reality” (p.79)
Essentially follows Plato’s premise that there must be something like the Forms but modifies or improves upon Plato’s theory of reality.
Positive features:
Negative features:
Adherents:
Plato
Aristotle
St Augustine
St. Thomas Aquinas
Realism

23. Realism Alternative 2: Nominalism
“The doctrine that Forms, or Universals, are merely universal names by which we group together things that possess similar features” (p.79)
Maintains that Forms and essences (universals) do not have any independent existences. They are just words we use to group things together with similar features.
Positive Features:
Negative Features:
Adherents:
William of Ockham
W.V.O. Quine
Realism

24. Realism Alternative 3: Conceptualism
“The doctrine that universals are material constructs, and as such really exist in the mind” (p.79)
Accepts the existence of Universals, essences, etc. but they do not exist independently or transcendentally; they exist in the mind. Hence we can talk and have knowledge about reality.
Positive Features:
Negative Features:
Realism

25. Summary

26. Plato’s Theory of Forms
Summary of Plato’s Theory of Reality
Reality is composed of two distinct worlds:
The world of Being
The world of Becoming
Objects in each world have radically different properties.
Forms in the world of Being impart essence (Whatness) onto objects in the world of Becoming
Plato divides between Higher Forms (things without physical manifestation) and Lower Forms (things that manifest physically)
Plato further clarifies his theory of reality using the ‘Divided Line’ analogy.
The ultimate form and the source of all existence and knowledge is the form of the ‘Good’
Plato uses the ‘Analogy of the Cave’ to further illustrate the Form of the Good
Plato’s Theory of Forms