The Philosophy
of Plato
A Brief History of Plato
Born in Athens in 427 BCE
 Disciple of Socrates
 Plato’s philosophy was influenced by
Socrates
 Founded the Academy, to train leaders in
philosophy, in Athens in 387

Plato’s Dialogues
Early Dialogues
Middle Dialogues
Later Dialogues
Apology
Gorgias
Symposium
Crito
Meno
Phaedo
Laches
Euthydemus
Republic,
Euthyphro
Hippias
Timaeus
Republic,
Book 1
I and II
Cratylus
Books 2-10
Laws
•Most of Plato’s philosophical writing is in the form of
dialogues
•Total of 42 Dialogues
•Socrates is used in all of Plato’s Dialogues
Early Dialogues
Wrote them before he had a philosophy of
his own
 Socrates is portrayed historically accurately
 Mainly critical of the moral views of others

Middle Dialogues
Begins coming up with his own philosophy
 Develops some metaphysical (philosophical
principles) and epistemological (nature of
knowledge) positions.
 Begins introducing his theory of the forms
into his writing

Late Dialogues
Socrates is used purely to advance Plato’s
own views
 His approach is constructive—used mainly
to develop his own mature philosophical
system

General Ideas
Inherited Socrates’s philosophy
 Attempted to complete it by adding a
foundation in metaphysics
 Believed philosophy must render man
morally better

The Socratic Philosophy


The only real wisdom is knowing that you know
absolutely nothing
The highest good is the improvement of the soul—
the care for wisdom and truth
– Virtue does not come from money, but money come
from virtue

Virtue is knowledge
– Evil and wrongdoing come from lack of knowledge or
ignorance
The Concept of the Philosopher-King
Plato initially thought revising the Athenian
constitution would end the moral
degeneration of Athens
 Then realized philosophy was the key
 Only kings that knew philosophy or
philosophers that were kings would know
what true justice was.

Plato’s Metaphysics
There is a distinction between “things” and
“forms”
 This must be understood before being able
to understand Plato
 “Things” are what we can perceive with our
senses
 “Forms” are eternal and static

Theory of Knowledge
Thought
Objects
Reason
(Dialectic)
Higher Forms
Understanding
(Science and
Mathematics)
Forms of Science
and Mathematics
Belief
(Perception)
Things, Objects
Knowledge
Opinion
Conjecture
(Imagination)
Shadows,
Images,
Reflections
Intelligible
World
Visible World
Imagination or Conjecture
Level 1
Imagination is the lowest level on the
divided line of knowledge
 Mental activity is at a minimum

– Awareness of shadows, optical illusions, and
the like
Belief
Level 2
Begins to have common sense
 Perception of concrete objects occur at this
level

– Recognition of things such as threedimensional visible objects

Classification and organization of perceived
objects begin at this level
Rational Understanding or Intellect
Level 3
The crossing of the line represents the
change from the knowledge of a plumber to
the knowledge of a civil engineer
 Perception of abstract objects occur at this
level

The Theory of Two Worlds
Sensible World
World of the Forms
appearance (seems real)
reality (is real)
immanent (within space and time)
transcendent (beyond space and time)
becoming (ever changing)
being (eternal and unchanging)
particular and imperfect
absolute and perfect
many instances (copy; imitation)
one essence (archetype)
perceived by senses
known by reason
subjective (dependent upon my
perception)
objective (exist independently of my
mind)
Examples: a computer, a person
Examples: Justice, Goodness
The World of the Forms
The world of Forms is the “real” world
 Forms are abstract
 Things that can be perceived by the senses
can be derived from Forms.
 The world of Forms consists of eternal and
unchanging abstract concepts such as
Justice and Beauty

The Sensible World

The Sensible world is a shadow or imitation of the
world of Forms
– The shadow represents a concrete object



It is impossible to derive a Form from a Sensible
thing
Sensible things only exist because of participation
A book comes into being because it is
participating in the form of Bookness.
Significance of the Two World
Theory
Why would Plato need to develop such a
complicated metaphysical system?
 Plato used this system to counteract the
Sophists’ relativism
 The Sophists believed that true and false,
good and bad, were merely opinions.
 This would have led to the death of
philosophy

Reason
Level 4


Highest level of knowledge
Mind uses the method of dialectic
– Dialectic is the crown-science of all sciences


Dialectic identifies all of the forms
A philosopher can attain the knowledge of
dialectic through love of truth, which enables him
to reach the Idea of the Good, the supreme form
– The Idea of the Good gives truth which makes the
forms intelligible
The Tripartite Soul

Man is made of 3 elements
– Ability to use language and reason
– Bodily desires and needs
– Emotional drives such as anger and sorrow
Justice in the Soul
Justice for a man is functioning in
accordance with his form, the three parts of
his soul
 Reason may know good, but it is in conflict
with bodily desires

The Soul as Organism
The dysfunction of any of the three
elements causes the soul to lose its wellbeing
 Neither a life devoted to bodily desires nor
a life devoted to denial of bodily desires
would be functional

Conflict Within the Soul
Reason comes into conflict with the bodily
appetites
 The third element, emotional drives, serves
as a mediator of conflicts

– It can act on behalf of either reason or the
appetites
The Theory of the Three Types of
Souls
The person dominated by reason seeks
wisdom
 The person dominated by emotional drives
seeks success and fame
 The person dominated by bodily appetites
seeks material wealth

Ethics: The Good Life
Pleasure is not the highest good for humans
 Pursuing pleasure as the highest good will
destroy you
 Highest good consists of fulfilling all three
elements in the proper order

– First, reason
– Then emotional drives
– Last, bodily appetites
The Harmony of the Soul
The three elements of the soul form a
harmony like a musical harmony
 The good life is the harmoniously balanced
life, which satisfies all three elements
 This is the Good Life, the life of human
happiness

Government

When a society called on itself to fulfill its needs, Plato
had a social structure:
– The philosophers direct the state;
– The warriors defend the state;
– The producers must attend to the material production of those
things that are needed by the state.
• Divided further by skills and jobs

Plato is strictly aristocratic
– Philosophers direct the state because they are wise and they know
of the Eternal Forms, the constant forms of Knowledge.
– Also, they know the essence of the state and show the other two
lower classes the way that must be followed in order to attain the
end of the state
Bibliography







www.rit.edu/~flwstu/plato.html
Book of Knowledge Encyclopedia
www.philosophypages.com/hy/2f.htm#memo
www.philosophypages.com/hy/2g.htm#jui
www.philosophypages.com/hy/2h.htm#women
www.radicalacademy.com/adiphilmetaphysical2.html
From Socrates to Sartre: the Philosophic Quest
Author: T. Z. Lavine