Plato's long dialogue Republic is traditionally divided into ten books, but the beginnings
and endings of these books are somewhat arbitrary.
Here is a different way of dividing up Republic, according to topic, into eleven different parts.
The beginnings and endings of these parts do not always correspond to the breaks between
the books in Republic.
Part 1 of Republic is a discussion of justice and injustice.
It comprises all of Book 1 and the beginning of Book 2.
In it we have Cephalus, the old man, give a preliminary discussion, which sets the framework
for the conversation that follows.
His son Polemarchus then defends the conventional view of justice, the common sense view.
Thrasymachus then makes his case for injustice, in two parts.
Glaucon and Adeimantus, after Thrasymachus’ departure, then restate the case for injustice
in their own words.
Part 2 of Republic is a discussion of the nature of the city.
It begins with the first principles of social and political organization, then discusses
the requirements of advanced civilized society.
And because this society will require Guardians in order to function, it begins a discussion
of the qualities that will be required in the Guardians, in order for them to function well.
Part 3 of Republic discusses the education of the Guardians.
It begins with their literary education and the need for a suitable literature.
At the end of what we call Book 2, it gives a criticism of the theological unsuitability
of the current Greek literature, and then begins in Book 3 to criticize the moral instruction
offered by current Greek literature.
Plato then discusses the requirements of a suitable education for these Guardians, both
formal and musical requirements, gives a summary and then a discussion of the physical education
and physical training that these Guardians will require.
Part 4 discusses the Guardians as rulers and as auxiliaries or military personnel in the
ideal city.
It gives the three classes of people in the city and their mutual relations.
It discusses the rulers’ and auxiliaries’ way of life and makes some final provisions
for the unity of the city.
Part 5 is a discussion of justice in society and in the individual soul.
A discussion of justice in the ideal city is followed by an analysis of the elements
of mental conflict and the nature of justice in the individual soul.
In Part 6 Plato turns to women and the family.
After discussing the status of women, he gives some views on marriage and the family in the
ideal city and the rules that will govern warfare.
Part 7, one of the longest parts in the book, discusses the Philosopher-Ruler or Philosopher-King.
It begins at the end of Book 5, with a discussion of the ideal and the actual city and whether
the city being described could exist in reality.
Plato then gives a definition of the philosopher in terms of the two orders of reality and
the qualities of character that the philosopher will need to possess in order to rule the
ideal city.
Plato then discusses the popular prejudice against philosophy, and the possibility of
there being a Philosopher-King or Philosopher-Ruler.
He then approaches the idea that the Good is the ultimate object of knowledge, and looks
at the implications of this.
And here is where we find the Metaphysical Interlude, the three great analogies or images
that Plato gives us at the end of Book 6 and beginning of Book 7: the analogy of the Sun,
the image of the divided line, and the allegory of the cave.
In Part 8 of Republic, Plato discusses the education that the philosopher will require.
He goes through the mathematical studies that philosophers will need to perform, and then
discusses their training in dialectic and the nature of the curriculum and how decisions
will be made about what subjects to teach to whom.
Part 9 covers the nature of imperfect societies and the characters, the individual souls,
that correspond to them.
These are societies and people that fall short of the ideal previously described.
After a recapitulation, Plato discusses four types of regime: timocracy, oligarchy, democracy,
and tyranny, and the qualities of personal character in the individual soul that correspond
to them.
This discussion bleeds into Book 9 of Republic, with a discussion of the types of character
and their degrees of happiness.
This is where we discover the answer to the question raised in Book 2 about the profitability
of justice.
This is where we learn that the Philosopher-Ruler is the happiest of all people, with the best
life, and the tyrant, the person with a tyrannical soul, is the most miserable and least successful
of all human beings.
In Part 10, Plato gives us his theory of art, discussing art and illusion and the appeal
of art and poetry and the effects that poetry and drama have on human souls.
Part 11, the final part, turns to the question of the immortality of the soul, the rewards
of goodness in this life, and the famous image of the Myth of Er, the reincarnation myth
that brings Plato's Republic to a close.