Socrates engages in a discussion with Polemarchus, Cephalus, Thrasymachus, Glaucon, and Adeimantus about the definition of justice. Thrasymachus argues that justice is defined by the interests of the stronger, but Socrates refutes this by claiming justice promotes social harmony while injustice divides society. Glaucon and Adeimantus are not convinced that justice is intrinsically good and ask Socrates to prove that the just life is happier than the unjust life. To do so, Socrates proposes examining the nature of justice in an ideal city-state.

1. THE
REPUBLIC
-Plato

2. By
David Moses

3. The Republic is a Socratic
dialogues, written by Plato around 380
BCE, concerning the definition of justice,
the order and character of the just city-
state and the just man. For this reason,
ancient readers used the name On
Justice as an alternative title

5. CONTEXTUAL INFORMATION
 When Book I opens, Socrates is returning home from a
religious festival with his young friend Glaucon, one of
Plato’s brothers.
 Ironic situation:
 A torch-race on horseback in honor of the goddess;
 Why is it a novelty?
 What’s so dangerous?

6. GOT WAYLAID BY FORCE (OF THE
STRONGER)
• On the road, Socrates and his companions are waylaid by
Adeimantus, another brother of Plato, and the young
nobleman Polemarchus, who convinces them to take a
detour to his house.
• There they join Polemarchus’s aging father Cephalus, and
others. Socrates and the elderly man begin a discussion on
the merits of old age. This discussion quickly turns to the
subject of justice.
• “And are you stronger than all these? for if not, you will

7. CONVERSATION & JOURNEY
REASON BY ANALOGY
 “… the more the pleasures of the body fade away, the
greater to me is the pleasure and charm of
conversation.”
 “He replied: There is nothing which for my part I like
better, Cephalus, than conversing with aged men; for I
regard them as travelers who have gone a journey
which I too may have to go, and of whom I ought to
enquire, whether the way is smooth and easy, or

8. PATRIMONY
 1. An estate inherited from one's father or ancestors.
 2. Any quality, characteristic, etc., that is inherited;
heritage.
 3. The aggregate of one's property.
 4. The estate or endowment of a church, religious
house, etc.

9. REASON BY ANALOGY
… “the makers of fortunes have a second love of money
as a creation of their own, resembling the affection of
authors for their own poems, or of parents for their
children, besides that natural love of it for the sake of use
and profit which is common to them and all men”.

10. OLD AGE, WEALTH, REFLECTION SUCH
TOPICS LEAD TO JUSTICE
“… when a man thinks himself to be near death, fears and cares
enter into his mind which he never had before; the tales of a world
below and the punishment which is exacted there of deeds done
here were once a laughing matter to him, but now he is tormented
with the thought that they may be true: either from the weakness
of age, or because he is now drawing nearer to that other place, he
has a clearer view of these things; suspicions and alarms crowd
thickly upon him, and he begins to reflect and consider what
wrongs he has done to others”.

11. WHAT IS JUSTICE?
RESTORATIVE JUSTICE
 Simonides (a minor Greek poet): Speak the truth and
pay your debt;
 Justice is to return what is due;
 Socrates’ challenge: Justice is more than just return
what is due.

12. SOCRATES SHIFTED A CONCEPT
REASON VS. FALLACY
 To return what you own to
someone;
 This falls into restorative
justice;
 To return a weapon to a
murderer is a different
situation;
 Socrates did not offer the
scenario how we got this
weapon from the murderer
in the first place. After the
murder, the murderer is no
longer entitled to his
weapon. The law will
override his ownership of
the weapon.

13. JUSTICE IS TO DO GOOD TO A FRIEND,
EVIL TO AN ENEMY.
• Says Polemarchus quoting Siꞌmonides, 556?–468? b.c.,
Greek poet: justice is the art that gives good to a friend, evil to an
enemy.
(challenge this definition)
• Traditionally, the Greek conception of justice came from poets like
Hesiod, who in Works and Days presents justice as a certain set of
acts that must be followed. The reason for being just, as presented
by the traditional view, was consideration of reward and
punishment: Zeus rewards those who are good and punishes those
who are bad.

14. SHOULD WE HARM OUR ENEMIES?
What If We Are On The Wrong Side Of History?
Socrates reveals many inconsistencies in this view. He
points out that, because our judgment concerning friends
and enemies is fallible, this credo will lead us to harm the
good and help the bad. We are not always friends with
the most virtuous individuals, nor are our enemies
always the scum of society. Socrates points out that there
is something incoherent in the idea of harming someone
(even if our enemy) through justice.

15. IF WE ARE IGNORANT OF HUMAN NATURE,
CAN WE TELL WHO ARE OUR FRIENDS AND
WHO ARE OUR ENEMIES?
 “But see the consequence: -Many a man who is
ignorant of human nature has friends who are bad
friends, and in that case he ought to do harm to them;
and he has good enemies whom he ought to benefit”
 Stiff application (paralysis in James Joyce’s words) of
the rule that we should do good to our friends and do
harm to our enemies could be consequential.

16. JUSTICE IN UTILITARIAN VIEW
 Socrates: You think that justice may be of use in peace as well as in
war?
 Is justice something that is useful? If it is, it is useful always for
something else. Then the definition is shifted to something external.
 Justice has its criteria, independent of utilities.
 Autonomous vs. heteronomous
 Heteronomy: the condition of being under the domination of an
outside authority, either human or divine.
 Autonomy: freedom, independence, free of external influences, out
of your own free will, your own choice;

17. THRASYMACHUS’ DEFINITION OF
JUSTICE Listen, then, he said; I proclaim that justice is nothing else than
the interest of the stronger.
 Analysis is to take things apart.
 For Thrasymachus, justice is tied to interest on the one hand; and
to the stronger on the other.
 Political power grows out of the barrel of a gun ... Mao Zedong
(1893 – 1976)

18. THRASYMACHUS’
FALLACY
Something that prevails must be right!
 Thrasymachus cited so
many pieces of
empirical evidence to
support that justice is
the interest of the
stronger.
 Reflect on the
limitations of
Empiricism!
 But all this is reversed
in the case of the unjust
man. I am speaking, as
before, of injustice on a
large scale in which the
advantage of the unjust
is more apparent;
 Thrasymachus says that the life of the unjust is more advantageous than
that of the just,
 Tied to benefits/interests
 Warranted by the large number;
 Everywhere…
 But it doesn’t necessarily mean it is right.

19. SOCRATES: JUSTICE IS
HARMONY
 And this is because injustice creates divisions and
hatreds and fighting, and justice imparts harmony and
friendship; is not that true, Thrasymachus?
 And is not injustice equally fatal when existing in a
single person; in the first place rendering him incapable
of action because he is not at unity with himself, and in
the second place making him an enemy to himself and
the just? Is not that true, Thrasymachus?

20. REASON BY ANALOGY IT IS
INTERDISCIPLINARY IN NATURE
Moving from one context to another context;
If something holds true in one context, but not
true in another context, then it is not universal.
Reason by analogy is a way to test if a
theory/claim holds water or not.

21. THE LAW OF CONTRADICTION
 In classical logic, the law of non-contradiction (LNC) (or the
principle of non-contradiction (PNC), or the principle of
contradiction) is the second of the so-called three classic laws of
thought. It states that contradictory statements cannot both at
the same time be true, e.g. the two propositions "A is B" and "A
is not B" are mutually exclusive.

22. JUSTICE & INTEREST
 “… and as the government must be supposed to have
power, the only reasonable conclusion is, that
everywhere there is one principle of justice, which is
the interest of the stronger” (11).
 Here Thrasymachus associated justice with interest,
and interest are translated into benefits.

23. IN PLATO’S EARLY DIALOGUES,
APORIA USUALLY SPELLS THE END
 1. Rhetoric . the expression of a simulated or real doubt, as
about where to begin or what to do or say.
 2. Logic, Philosophy . a difficulty encountered in establishing
the theoretical truth of a proposition, created by the presence of
evidence both for and against it.

25. Glaucon asks Socrates whether justice belongs
1) in the class of good things we choose to have for
themselves, like joy, or
2) those we value for their consequences though they
themselves are hard, like physical training, or 3) the things
we value for themselves and their consequences, like
knowledge. Socrates says justice is in the third and best
group. Glaucon says that most people would say justice is
valued not for itself but for its consequences, for justice is
difficult, and thus often avoided.
GLAUCON WANTS TO BE
CONVINCED THAT JUSTICE IS A
VIRTUE

26. First, it is generally agreed that to do injustice is naturally
good, but to suffer it, bad. Consequently men make laws,
and what the laws require, they call just. The origin of
justice is a compromise between right and wrong.
GLAUCON REVIEWS THRASYMACH
US' ARGUMENTS ABOUT JUSTICE

27. People value justice because they lack the power to do
injustice. Justice is practiced only by compulsion, and for
the good of others, since injustice is more rewarding than
justice. Human nature inclines us towards injustice, but
the law forces us to behave justly.
LACK THE POWER TO DO INJUSTICE

28. Glaucon tells the story of Gyges` ring. A shepherd
discovers a ring that makes its wearer invisible. The
shepherd uses the ring to seduce the queen, murder the
king and take the throne. If the power to do injustice were
given to those who are usually too powerless to practice
injustice, then, like the shepherd with the ring, they would
be as unjust as others.
STORY OF GYGES' RING

29. Glaucon's brother Adeimantus says that it is merely the
appearance of justice that is praised. An unjust person who has a
reputation for justice leads a life of pleasure. The God perceive
truth and punish the unjust, but God can be persuaded by prayers
and sacrifices purchased by the unjust who have profited from
their crimes.
GOD` APPEARANCE OF JUSTICE

30. Glaucon asks Socrates to describe what justice and
injustice each do in themselves, how justice benefits those
who have justice and how injustice harms them.
Socrates proposes first to examine the justice of the city,
because it is easier to determine what is just for the group
then for the individual. He begins by specifying what the
ideal city, the kallipolis, needs.
SOCRATES IS PROPOSING TO ARGUE
FROM THE GENERAL

31. A city needs people, food, shelter, and goods, with each
person specializing in a particular occupation. The city
needs merchants to trade with other cities, a marketplace,
currency, local retailers, and people who perform manual
labor for a wage. Luxury goods and services require a
larger city, which leads to war to acquire more land. War
requires an army, and soldiers require special skills.
IMPORTANT ASPECTS OF THE IDEAL CITY

32. Socrates examines the requirements of soldiers or
"guardians." A guardian needs to be gentle to his own
people, but harsh to others. Therefore the guardian must
be a lover of learning, a philosopher, educated from
childhood in music and poetry, then given physical
training.
IMPORTANCE OF EDUCATION AND
PHILOSOPHY.

33. Poets, like Hesiod and Homer, tell inappropriate stories
about gods committing impious actions, stories which
might influence the citizens to act badly. Therefore,
the city must only use stories depicting good behaviour so
as to influence the citizens of the city in positive ways.
SOCRATES, AND HENCE SOCRATES‘
PUPPET-MASTER PLATO