Plato's Republic and Aristotle's Nicomachean Ethics

PHI 420: Topics in Philosophy

Instructor: Thomas A. Blackson
Pre-requisites: PHI 328 (History of Ancient Philosophy) or its equivalent is helpful but not required

Olympic runners, c. 525 BCE

Some Online Resources:

Perseus Digital Library:
Plato, Republic
Aristotle, Nicomachean Ethics

Loeb Classical Library:
Plato, Republic

Stanford Encyclopedia of Philosophy:
Plato's Ethics: An Overview
Plato's Ethics and Politics in The Republic
Aristotle's Ethics

History of Philosophy Without Any Gaps
This course is a study of Plato's Republic and Aristotle's Nicomachean Ethics.

In the Republic, the subject is justice. Socrates explains what justice is in a "city" (πόλις) and in a human being, and he argues that the just life is better than the unjust life.

In the Nicomachean Ethics, the subject is the good life. Aristotle supplies missing details and removes what he regards as mistakes in the conception of the good life in the Republic.


English translations of Plato's Republic and Aristotle's Nicomachean Ethics are freely available in the Perseus Digital Library. The translations are older but still very good.

If you want newer translations, I recommend Plato. Republic (Translated by G. M. A. Grube. Revised by C. D. C. Reeve (Hackett Publishing, 1992)) and Aristotle. Nicomachean Ethics, 2nd edition (Translated, with Introduction, by Terence Irwin (Hackett Publishing, 2000)).

In addition to these primary sources, there are lecture notes for each unit.


The letter grade for the course is a function of the point grades on five writing assignments, six discussion posts, and a bibliography project. Each writing assignment is worth 10 points. Each discussion post is worth 5 points. The bibliography project is worth 20 points.

In a discussion post, you are to call attention to something in the reading you found interesting and you are to explain why you found it interesting. These posts must be thoughtful. Discussion posts written with little care and attention to detail will not receive full credit.

In the writing assignments, your answer is to take the form of a short essay that demonstrates that you understand the historical and philosophical issues related to the question.

In the bibliography project, you are to analyze five academic journal articles or book chapters from the scholarly literature on issues related to the Republic or Nicomachean Ethics.

The assignments (50 points), discussions (30 points), and bibliography project (20 points) total to 100 points. There is no extra credit, and late work is not accepted without good reason. The point total determines the letter grade: A+ (100-97), A (96-94), A- (93-90), B+ (89-87), B (86-84), B- (83-80), C+ (79-77), C (76-70), D (69-60), E (59-0). Incompletes are given only to accommodate serious illnesses and family emergencies, which must be adequately documented.


Plato, 427-347 BCE. Aristotle, 384-322 BCE.

The Greek title is Πολιτείᾳ. ("[I]t is possible for the citizens to have children, wives and possessions in common with each other, as in Plato's Republic (Πολιτείᾳ), in which Socrates says that there must be community of children, women and possessions" (Aristotle Politics II.1261a).) The English 'republic' derives from the Latin res publica, which is the subject of Cicero's De re publica (or "About the res pubica").
We will read most of Plato's Republic and Aristotle's Nicomachean Ethics. Our interest is primarily historical. We want to know what Plato and Aristotle thought and why they thought it.


Socrates, 470-399 BCE.

Among Plato's dialogues, only the Laws is longer.
Plato was in the circle around Socrates. In 399 BCE, when Plato was in his late twenties, the city of Athens executed Socrates. Sometime after that, Plato began writing his dialogues. The Republic is traditionally thought to be one of the greatest of these dialogues.

A common (but controversial) a strategy for interpreting Plato divides his dialogues into early, middle, and late dialogues. The assumption is that in the early dialogues Plato is trying to work out what Socrates thought and that in the middle dialogues he is exploring possible solutions to problems he has uncovered. With the possible exception of Book I, the Republic is a middle dialogue. Socrates is the chief interlocutor, but unlike his practice in the early dialogues, he no longer just asks questions. In the middle dialogues, he argues for his views. In Books II-X of the Republic, he argues that the just life is better than the unjust life.

"When I [= Socrates] had said this I supposed that I was done with the subject, but it all [= Book I] turned out to be only a prelude (προοίμιον)" (Republic II.357a).
The Republic consists in ten books. Book I is in the style of an early definitional dialogue and constitutes an introduction to the Republic as a whole. Socrates' interlocutors are Cephalus, Polemarchus, Thrasymachus, and Plato's brothers (Gluacon and Adeimantus).

Lectures: Thinking about Socrates, The Opening Conversation
Reading: Republic I.327a-I.366e (Socrates, Cephalus, Polemarchus, Thrasymachus)
Assignment #1

Glaucon is disappointed with the outcome of the discussion in Book I. He challenges
Socrates not just to drive his interlocutors into contradiction but to demonstrate that
the just life really is better than the unjust life. Socrates accepts the challenge and tries
to meet it in the remaining books of the Republic. He begins by setting out what
justice is in a "city" (πόλις) and what it is in an individual human being.

Lectures: Justice in a City and in an Individual
Republic II.357a-II.367e (the demand for proof that justice is better)
Republic II.368a-II.376c (the birth of a city)
Republic III.412b-IV.427c (the guardians are rulers and auxiliaries)
Republic IV.427d-IV.434c (justice and injustice in a city)
Republic IV.434d-IV.444e (justice and injustice in an individual)
Assignment #2 or Assignment #3

Now that it is clear what justice is in the individual, Socrates argues that the
just life is better than the unjust life. The just life is the life of rulers in a just city. They
are "lovers of wisdom" (φιλόσοφοι). Their life is the most pleasant.

Lectures: The Just Life is Better than the Unjust Life
Republic IV.444e-445c (the just life is better than the unjust life)
Republic V.473c-VI.504a, Republic VII.540a-VII.541b (the rulers must be "philosophers")
Republic IX.580b-IX.587b (the rulers are first in happiness)
Assignment #4

The title seems to refer to Aristotle's son, Nicomachus, who may have edited the Nicomachean Ethics.

Aristotle was a member of Plato's Academy for twenty years. He entered in 367 BCE when he was seventeen and remained until 347 BCE, the year of Plato's death. Aristotle is the first great Platonist and Plato's first great critic. Aristotle accepts the broad outline of the Platonic framework, but he also corrects what he regards as its mistakes.

Aristotle thinks that the good life for a human being is a certain life of reason.

Lectures: The Good Life for a Human Being
Nicomachean Ethics I.1.1094a-I.3.1096a (the good life is the life of happiness)
Nicomachean Ethics I.7.1097a-I.8.1102a (the argument from function)
Assignment #5

Aristotle thinks that the good life for a human being takes two forms. The best form is the life of "contemplation" (θεωρία). The second best is the life of "practical wisdom" (φρόνησις).

Lectures: The First Best Life of Reason, The Second Best Life of Reason
Nicomachean Ethics I.13.1102a-II.6.1107a (virtue and the soul)
Nicomachean Ethics III.1.1109b-III.5.1115a ("choice" (προαίρεσις))
Nicomachean Ethics VI.1.1138b-VII.6.1145a (virtues of thought)
Nicomachean Ethics X.4.1174b-X.5.1176a (pleasure)
Nicomachean Ethics X.6.1176a-X.8.1179a ("happiness" (εὐδαιμονία))
Assignment #6 or Assignment #7

Aristotle has a "perfectionist" conception of the good life. In this he follows Plato. According to this understanding of the good life, one life is better than another to the extent that it is a more perfect realization of certain of the properties that constitute human nature. Plato and Aristotle develop this view against the background of their conception of what a human being is.

Lectures: Perfectionism in Plato and Aristotle
The Bibliography Project

Contact Information

Thomas A. Blackson
Philosophy Faculty
School of Historical, Philosophical, and Religious Studies
Lattie F. Coor Hall, room 3356
PO Box 874302
Arizona State University
Tempe, AZ. 85287-4302,, www.public.asu/~blackson