Plato's Republic and Aristotle's Nicomachean Ethics

Syllabus. 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

Plato. Republic. (Translated from the New Standard Greek Text, with Introduction, by C. D. C. Reeve). Hackett Publishing, 2004.

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. These translations are older but good enough for this class.

For newer translations, I recommend Plato. Republic (Translated from the New Standard Greek Text, with Introduction, by C. D. C. Reeve (Hackett Publishing, 2004)) and Aristotle. Nicomachean Ethics, 2nd edition (Translated, with Introduction, by Terence Irwin (Hackett Publishing, 2000)). These translations are relatively inexpensive, and you may find them more convenient to use than the digital translations in the Perseus Digital Library.

In addition to the links to the two texts, there are links to 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 should demonstrate that you understand the historical and philosophical issues related to the question. The best way to demonstrate your understanding is to provide answers understandable to someone who does not already know the answer.

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.

Πολιτείᾳ is the title. ("[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 works in dialogue form. The Republic is traditionally thought to be one of the greatest of these dialogues.

Socrates (Σωκράτης)
Cephalus (Κέφαλος)
Polemarchus (Πολέμαρχος), son of Cephalus
Thrasymachus (Θρασύμαχος)
Glaucon (Γλαύκων)
Adeimantus (Ἀδείμαντος)
The Republic consists in ten books.

Book I is an introduction to the Republic. Socrates' interlocutors are Cephalus, Polemarchus, Thrasymachus, and Plato's brothers (Gluacon and Adeimantus).

Book II represents a new beginning.

"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).
Glaucon is disappointed with the outcome of the previous discussion. He challenges Socrates to demonstrate that the just life is better.


The argument in the Republic is not initially easy to see. A good strategy is to read the lectures first.

Books I and II of the Republic

Republic I.327a-328c.   The opening scene.
Republic I.328c-331d.   Socrates talks with Cephalus.
Republic I.331d-336b.   Socrates talks with Polemarchus.
Republic I.336b-354b.   Socrates talks with Thrasymachus.
Republic I.354b-354c.   The conversation ends in perplexity.

Republic II.357a-358e.  Glaucon takes up the argument and challenges Socrates.   "[W]e have not invoked the rewards and reputes of justice as you said Homer and Hesiod do, but we have proved that justice in itself is the best thing for the soul itself, and that the soul ought to do justice whether it possess the ring of Gyges or not, or the helmet of Hades to boot.
  Most true, Socrates" (Republic X.612b).

Republic II.358e-362d.  Glaucon sets out the origin of justice.
Republic II.362d-367e.  Admeimantus clarifies Glaucon's challenge.

Writing Assignment:
Assignment #1
You are free to discuss the assignment and to post questions about it.


Books II, III, and IV set out what justice is in the city and in the individual human being. In this discussion, as part of the discussion of what justice is, Book IV contains an argument that the soul is tripartite and that the harmonious organization of the parts is justice in the individual.

Books II, III, and IV of the Republic
The Tripartite Theory of the Soul

Republic II.368c-369b.      The search for justice in the city.
Republic II.369b-372e.      The reason human beings organize themselves into a city.
Republic II.372e-374d.      The birth of a luxurious city.
Republic II.374d-III.412c. The education of the guardians.
Republic III.412c-414b.     The rulers are the best of the guardians.
Republic III.414b-417b.     The second-best among the guardians are auxiliaries.
Republic IV.419a-427d.     The aim is not to make one class outstandingly happy.
Republic IV.427d-434d.     What justice is in the city.
Republic IV.434d-435c.     What justice is in the individual human being.
Republic IV.435c-444e.      The Tripartite Theory of the Soul.
Republic IV.444e-445c.       Now it seems obvious that the just life is better.
Republic IV.445c-V.449b.  The forms of vice.

Writing Assignment:
Assignment #2
You are free to discuss the assignment and to post questions about it.


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 happiest and the most pleasant.

Books V-X of the Republic

Republic V.449b-472a.          Women and children and related matters.
Republic V.472a-VI.502d.     The rulers in a just city must be lovers of wisdom.
Republic VI.502d-VII.541b.  The training necessary to become a lover of wisdom.
Republic VIII.543a-IX.580a. The kinds of corrupted cities and characters.
Republic IX.580b-580d.          First in happiness.
Republic IX.580d-592b.          First in pleasure.
Republic X.595a-608d.            Imitation.
Republic X.608d-612b.           The immortality of the soul
Republic X.612b-621d.           The myth of Er.

Writing Assignment:
Assignment #3
You are free to discuss the assignment and to post questions about it.

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.


The Nicomachean Ethics consists in ten books, but the argument is not set out in a storyline as it is in the Republic. The Nicomachean Ethics reads more like a series of notes than finished work. This makes the argument initially difficult to see. A good strategy, again, is to read the lectures first.

The Good Life for a Human Being

Nicomachean Ethics I.1095a-I.1096a.        The good that is the aim of politics.
Nicomachean Ethics I.1097b-I.1098a.        The argument from function.
Nicomachean Ethics I.1102a-II.1109b.       Virtue and the soul.
Nicomachean Ethics III.1109b-1115a.        Necessary conditions for virtue.
Nicomachean Ethics III.1115a-IV.1128b.  Virtues of character.
Nicomachean Ethics V.1129a-1138b.          Justice.

Writing Assignment:
Assignment #4
You are free to discuss the assignment and to post questions about it.


Aristotle's view is uncertain, but he seems to think that the best life available to a human being is a life of reason in which "practical wisdom" (φρόνησις) arranges things for the sake of "contemplation" (θεωρία), that contemplation is necessary for "happiness" (εὐδαιμονία), and that a life with practical wisdom is happy to the extent it contains contemplation. The knowledge exercised in practical wisdom is the knowledge involved in making making choices well. By choosing in accordance with virtue, a human being with practical wisdom controls his life so that given the necessary external goods, he participates in "the [divine] life [of contemplation] according to the intellect" to the extent that this existence is possible for a human being.

Happiness is Contemplation
The Life according to the Intellect

Nicomachean Ethics VI.1138b-1145a.          Virtues of thought.
Nicomachean Ethics VII.1145a-1154b.         Continence, incontinence, pleasure.
Nicomachean Ethics VIII.1155a-IX.1172a.   Friendship.
Nicomachean Ethics X.1172a-1181b.             Pleasure, happiness, legislation.

Writing Assignment:
Assignment #5
You are free to discuss the assignment and to post questions about it.


This last unit is a brief look at a contemporary theory in which justice is understood to secure a less determinate conception of the good life than the one in Plato and Aristotle.

The "Aristotelian" Principle in the Rawlsian Theory of Justice

Writing Assignment:
Bibliography Project
You are free to discuss the assignment and to post questions about it.

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