Plato’s The Republic
(Com plete Notes)
Su m m ar y: B ook 1
In The Republic, Plato, speaking through his teacher Socrates, sets out to answer two
questions: What is justice? and Why should we be just? Book 1 sets up these challenges.
The interlocutors engage in a Socratic dialogue similar to that found in Plato’s earlier
works. While among a group of both friends and enemies, Socrates poses the
question, “What is justice?” He proceeds to refute every suggestion offered, showing
how each harbors hidden contradictions. Yet he offers no definition of his own, and the
discussion ends in aporia—a deadlock, where no further progress is possible and the
interlocutors feel less sure of their beliefs than they had at the start of the conversation.
In Plato’s early dialogues, aporia usually spells the end. The Republic moves beyond this
deadlock. Nine more books follow, and Socrates develops a rich and complex theory of
justice.
When Book 1 opens, Socrates is returning home from a religious festival with his young
friend Glaucon, one of Plato’s brothers. On the road, the three travelers 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.
Cephalus, a rich, well-respected elder of the city, and host to the group, is the first to
offer a definition of justice. Cephalus acts as spokesman for the Greek tradition. His
definition of justice is an attempt to articulate the basic Hesiodic conception: that justice
means living up to your legal obligations and being honest. Socrates defeats this
formulation with a counterexample: returning a weapon to a madman. You owe the
madman his weapon in some sense if it belongs to him legally, and yet this would be an
unjust act, since it would jeopardize the lives of others. So it cannot be the case that
justice is nothing more than honoring legal obligations and being honest.
At this point, Cephalus excuses himself to see to some sacrifices, and his son
Polemarchus takes over the argument for him. He lays out a new definition of justice:
justice means that you owe friends help, and you owe enemies harm. Though this
definition may seem different from that suggested by Cephalus, they are closely related.
They share the underlying imperative of rendering to each what is due and of giving to
each what is appropriate. This imperative will also be the foundation of Socrates’s
principle of justice in the later books. Like his father’s view, Polemarchus’s take on
justice represents a popular strand of thought—the attitude of the ambitious young
,politician—whereas Cephalus’s definition represented the attitude of the established, old
businessman.
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 some
incoherence in the idea of harming people through justice.
All this serves as an introduction to Thrasymachus, the Sophist. We have seen, through
Socrates’s cross-examination of Polemarchus and Cephalus, that the popular thinking
on justice is unsatisfactory. Thrasymachus shows us the nefarious result of this
confusion: the Sophist’s campaign to do away with justice, and all moral standards,
entirely. Thrasymachus, breaking angrily into the discussion, declares that he has a
better definition of justice to offer. Justice, he says, is nothing more than the advantage
of the stronger. Though Thrasymachus claims that this is his definition, it is not really
meant as a definition of justice as much as it is a delegitimization of justice. He is saying
that it does not pay to be just. Just behavior works to the advantage of other people, not
to the person who behaves justly. Thrasymachus assumes here that justice is the
unnatural restraint on our natural desire to have more. Justice is a convention imposed
on us, and it does not benefit us to adhere to it. The rational thing to do is ignore justice
entirely.
The burden of the discussion has now shifted. At first, the only challenge was to define
justice; now justice must be defined and proven to be worthwhile. Socrates has three
arguments to employ against Thrasymachus’ claim. First, he makes Thrasymachus
admit that the view he is advancing promotes injustice as a virtue. In this view, life is
seen as a continual competition to get more (more money, more power, etc.), and
whoever is most successful in the competition has the greatest virtue. Socrates then
launches into a long and complex chain of reasoning which leads him to conclude that
injustice cannot be a virtue because it is contrary to wisdom, which is a virtue. Injustice
is contrary to wisdom because the wise man, the man who is skilled in some art, never
seeks to beat out those who possess the same art. The mathematician, for instance, is
not in competition with other mathematicians.
Socrates then moves on to a new argument. Understanding justice now as the adherence
to certain rules which enable a group to act in common, Socrates points out that in order
to reach any of the goals Thrasymachus earlier praised as desirable one needs to be at
least moderately just in the sense of adhering to this set of rules.
Finally, he argues that since it was agreed that justice is a virtue of the soul, and virtue of
the soul means health of the soul, justice is desirable because it means health of the soul.
,Thus ends Book 1. Socrates and his interlocutors are no closer to a consensus on the
definition of justice, and Socrates has only advanced weak arguments in favor of justice’s
worth. But the terms of our challenge are set. Popular, traditional thinking on justice is
in shambles and we need to start fresh in order to defeat the creeping moral skepticism
of the Sophists.
An alysis: B ook 1
While The Republic is a book concerned with justice, it also addresses many other
topics. Some scholars go so far as to say that the book is primarily about something
other than justice. Critic Allan Bloom, for instance, reads the book first and foremost as
a defense of philosophy—as Socrates’s second “apology.” Socrates was executed by the
city of Athens for practicing philosophy. The leaders of Athens had decided that
philosophy was dangerous and sought to expel it from their city. Socrates had called the
old gods and the old laws into question. He challenged, and asked others to challenge,
the fundamental beliefs upon which their society rested.
In The Republic, Bloom says, Plato is trying to defend the act for which his teacher was
executed. His aim is to reveal why the philosopher is important, and what the
philosopher’s relationship to the city should be. While a philosopher is potentially
subversive to any existing regimes, according to Plato, he is crucial to the life of the just
city. Plato wanted to show how philosophy can be vital to the city. Bloom calls The
Republic the first work of political science because it invents a political philosophy
grounded in the idea of building a city on principles of reason.
Bloom’s interpretation follows from an understanding of Plato’s ideas about justice and
just cities in The Republic, which is how the book demands to be read at first. Looking
at The Republic as a work on justice, we first need to ask why justice has to be defended.
As Thrasymachus makes clear, justice is not universally assumed to be beneficial. For as
long as there has been ethical thought, there have been immoralists, people who think
that it is better to look out for your own interest than to follow rules of right and wrong.
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. In
late fifth century BCE, Athens, this conception of divine reward and retribution had lost
credibility. No one believed that the gods rewarded the just and punished the unjust.
People could see that many unjust men flourished, and many of the just were left
behind. In the sophisticated democracy that evolved in Athens, few were inclined to
train their hopes on the afterlife. Justice became a matter of great controversy.
Leading the controversy were the Sophists, the general educators hired as tutors to the
sons of the wealthy. The Sophists tended not to believe in objective truth, or objective
, standards of right and wrong. They regarded law and morality as conventions. The
Sophist Antiphon, for example, openly declared that we ought to be unjust when being
unjust is to our advantage.
Plato felt that he had to defend justice against these onslaughts. The Sophistic challenge
is represented in The Republic by Thrasymachus, who declares that justice is nothing
but the advantage of the stronger. Since this statement motivates the entire defense that
is to follow, it deserves analysis. What exactly does Thrasymachus mean by claiming
that justice is the advantage of the stronger? Who are the stronger? What is their
advantage?
On the first reading, Thrasymachus’s claim boils down to the basic Sophistic moral
notion that the norms and mores we consider just are conventions that hamper those
who adhere to them and benefit those who flout them. Those who behave unjustly
naturally gain power and become rulers and strong people in society. When stupid,
weak people behave in accordance with justice, they are disadvantaged, and the strong
are at an advantage. An alternate reading of Thrasymachus’s bold statement makes his
claim seem more subtle. On this reading, put forward by C.D.C. Reeve, Thrasymachus is
not merely making the usual assertion that the norms and mores of justice are
conventions; he is further claiming that these mores and norms are conventions put in
place by rulers to promote their own interests and to keep their subjects in a state of
oppression.
This second reading is interesting because it challenges not only our conception of right
and wrong, but Socrates’s usual way of finding truth. Socrates’s method
of elenchus proceeds by building up knowledge out of people’s true beliefs. If
Thrasymachus is right, then we do not have any true beliefs about justice. All we have
are beliefs forced on us by rulers. In order to discover the truth about right and wrong,
we must abandon the old method and start from scratch: building up knowledge without
resting on traditional beliefs. In the next book, Plato abandons the method of elenchus.
and begins the discussion from scratch.
Regardless of how we interpret Thrasymachus’s statement, the challenge to Socrates is
the same: he must prove that justice is something good and desirable, that it is more
than convention, that it is connected to objective standards of morality, and that it is in
our interest to adhere to it.
Su m m ar y: B ook 2, Par t 1 (357a–368c)
Socrates believes he has adequately responded to Thrasymachus and is through with the
discussion of justice, but the others are not satisfied with the conclusion they have
reached. Glaucon, one of Socrates’s young companions, explains what they would like
him to do. Glaucon states that all goods can be divided into three classes: things that we
desire only for their consequences, such as physical training and medical treatment;
(Com plete Notes)
Su m m ar y: B ook 1
In The Republic, Plato, speaking through his teacher Socrates, sets out to answer two
questions: What is justice? and Why should we be just? Book 1 sets up these challenges.
The interlocutors engage in a Socratic dialogue similar to that found in Plato’s earlier
works. While among a group of both friends and enemies, Socrates poses the
question, “What is justice?” He proceeds to refute every suggestion offered, showing
how each harbors hidden contradictions. Yet he offers no definition of his own, and the
discussion ends in aporia—a deadlock, where no further progress is possible and the
interlocutors feel less sure of their beliefs than they had at the start of the conversation.
In Plato’s early dialogues, aporia usually spells the end. The Republic moves beyond this
deadlock. Nine more books follow, and Socrates develops a rich and complex theory of
justice.
When Book 1 opens, Socrates is returning home from a religious festival with his young
friend Glaucon, one of Plato’s brothers. On the road, the three travelers 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.
Cephalus, a rich, well-respected elder of the city, and host to the group, is the first to
offer a definition of justice. Cephalus acts as spokesman for the Greek tradition. His
definition of justice is an attempt to articulate the basic Hesiodic conception: that justice
means living up to your legal obligations and being honest. Socrates defeats this
formulation with a counterexample: returning a weapon to a madman. You owe the
madman his weapon in some sense if it belongs to him legally, and yet this would be an
unjust act, since it would jeopardize the lives of others. So it cannot be the case that
justice is nothing more than honoring legal obligations and being honest.
At this point, Cephalus excuses himself to see to some sacrifices, and his son
Polemarchus takes over the argument for him. He lays out a new definition of justice:
justice means that you owe friends help, and you owe enemies harm. Though this
definition may seem different from that suggested by Cephalus, they are closely related.
They share the underlying imperative of rendering to each what is due and of giving to
each what is appropriate. This imperative will also be the foundation of Socrates’s
principle of justice in the later books. Like his father’s view, Polemarchus’s take on
justice represents a popular strand of thought—the attitude of the ambitious young
,politician—whereas Cephalus’s definition represented the attitude of the established, old
businessman.
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 some
incoherence in the idea of harming people through justice.
All this serves as an introduction to Thrasymachus, the Sophist. We have seen, through
Socrates’s cross-examination of Polemarchus and Cephalus, that the popular thinking
on justice is unsatisfactory. Thrasymachus shows us the nefarious result of this
confusion: the Sophist’s campaign to do away with justice, and all moral standards,
entirely. Thrasymachus, breaking angrily into the discussion, declares that he has a
better definition of justice to offer. Justice, he says, is nothing more than the advantage
of the stronger. Though Thrasymachus claims that this is his definition, it is not really
meant as a definition of justice as much as it is a delegitimization of justice. He is saying
that it does not pay to be just. Just behavior works to the advantage of other people, not
to the person who behaves justly. Thrasymachus assumes here that justice is the
unnatural restraint on our natural desire to have more. Justice is a convention imposed
on us, and it does not benefit us to adhere to it. The rational thing to do is ignore justice
entirely.
The burden of the discussion has now shifted. At first, the only challenge was to define
justice; now justice must be defined and proven to be worthwhile. Socrates has three
arguments to employ against Thrasymachus’ claim. First, he makes Thrasymachus
admit that the view he is advancing promotes injustice as a virtue. In this view, life is
seen as a continual competition to get more (more money, more power, etc.), and
whoever is most successful in the competition has the greatest virtue. Socrates then
launches into a long and complex chain of reasoning which leads him to conclude that
injustice cannot be a virtue because it is contrary to wisdom, which is a virtue. Injustice
is contrary to wisdom because the wise man, the man who is skilled in some art, never
seeks to beat out those who possess the same art. The mathematician, for instance, is
not in competition with other mathematicians.
Socrates then moves on to a new argument. Understanding justice now as the adherence
to certain rules which enable a group to act in common, Socrates points out that in order
to reach any of the goals Thrasymachus earlier praised as desirable one needs to be at
least moderately just in the sense of adhering to this set of rules.
Finally, he argues that since it was agreed that justice is a virtue of the soul, and virtue of
the soul means health of the soul, justice is desirable because it means health of the soul.
,Thus ends Book 1. Socrates and his interlocutors are no closer to a consensus on the
definition of justice, and Socrates has only advanced weak arguments in favor of justice’s
worth. But the terms of our challenge are set. Popular, traditional thinking on justice is
in shambles and we need to start fresh in order to defeat the creeping moral skepticism
of the Sophists.
An alysis: B ook 1
While The Republic is a book concerned with justice, it also addresses many other
topics. Some scholars go so far as to say that the book is primarily about something
other than justice. Critic Allan Bloom, for instance, reads the book first and foremost as
a defense of philosophy—as Socrates’s second “apology.” Socrates was executed by the
city of Athens for practicing philosophy. The leaders of Athens had decided that
philosophy was dangerous and sought to expel it from their city. Socrates had called the
old gods and the old laws into question. He challenged, and asked others to challenge,
the fundamental beliefs upon which their society rested.
In The Republic, Bloom says, Plato is trying to defend the act for which his teacher was
executed. His aim is to reveal why the philosopher is important, and what the
philosopher’s relationship to the city should be. While a philosopher is potentially
subversive to any existing regimes, according to Plato, he is crucial to the life of the just
city. Plato wanted to show how philosophy can be vital to the city. Bloom calls The
Republic the first work of political science because it invents a political philosophy
grounded in the idea of building a city on principles of reason.
Bloom’s interpretation follows from an understanding of Plato’s ideas about justice and
just cities in The Republic, which is how the book demands to be read at first. Looking
at The Republic as a work on justice, we first need to ask why justice has to be defended.
As Thrasymachus makes clear, justice is not universally assumed to be beneficial. For as
long as there has been ethical thought, there have been immoralists, people who think
that it is better to look out for your own interest than to follow rules of right and wrong.
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. In
late fifth century BCE, Athens, this conception of divine reward and retribution had lost
credibility. No one believed that the gods rewarded the just and punished the unjust.
People could see that many unjust men flourished, and many of the just were left
behind. In the sophisticated democracy that evolved in Athens, few were inclined to
train their hopes on the afterlife. Justice became a matter of great controversy.
Leading the controversy were the Sophists, the general educators hired as tutors to the
sons of the wealthy. The Sophists tended not to believe in objective truth, or objective
, standards of right and wrong. They regarded law and morality as conventions. The
Sophist Antiphon, for example, openly declared that we ought to be unjust when being
unjust is to our advantage.
Plato felt that he had to defend justice against these onslaughts. The Sophistic challenge
is represented in The Republic by Thrasymachus, who declares that justice is nothing
but the advantage of the stronger. Since this statement motivates the entire defense that
is to follow, it deserves analysis. What exactly does Thrasymachus mean by claiming
that justice is the advantage of the stronger? Who are the stronger? What is their
advantage?
On the first reading, Thrasymachus’s claim boils down to the basic Sophistic moral
notion that the norms and mores we consider just are conventions that hamper those
who adhere to them and benefit those who flout them. Those who behave unjustly
naturally gain power and become rulers and strong people in society. When stupid,
weak people behave in accordance with justice, they are disadvantaged, and the strong
are at an advantage. An alternate reading of Thrasymachus’s bold statement makes his
claim seem more subtle. On this reading, put forward by C.D.C. Reeve, Thrasymachus is
not merely making the usual assertion that the norms and mores of justice are
conventions; he is further claiming that these mores and norms are conventions put in
place by rulers to promote their own interests and to keep their subjects in a state of
oppression.
This second reading is interesting because it challenges not only our conception of right
and wrong, but Socrates’s usual way of finding truth. Socrates’s method
of elenchus proceeds by building up knowledge out of people’s true beliefs. If
Thrasymachus is right, then we do not have any true beliefs about justice. All we have
are beliefs forced on us by rulers. In order to discover the truth about right and wrong,
we must abandon the old method and start from scratch: building up knowledge without
resting on traditional beliefs. In the next book, Plato abandons the method of elenchus.
and begins the discussion from scratch.
Regardless of how we interpret Thrasymachus’s statement, the challenge to Socrates is
the same: he must prove that justice is something good and desirable, that it is more
than convention, that it is connected to objective standards of morality, and that it is in
our interest to adhere to it.
Su m m ar y: B ook 2, Par t 1 (357a–368c)
Socrates believes he has adequately responded to Thrasymachus and is through with the
discussion of justice, but the others are not satisfied with the conclusion they have
reached. Glaucon, one of Socrates’s young companions, explains what they would like
him to do. Glaucon states that all goods can be divided into three classes: things that we
desire only for their consequences, such as physical training and medical treatment;
