Outline of Plato’s View of Justice and the Soul

Plato is a soul man! This post summarizes and outlines book 1 of the Republic. Good review for students in Phil. 101 and other interested readers.

Let’s get started.

Plato is dialoguing with two characters: Glaucon and Thrasymachus, two Greeks who challenge Socrates to define justice.

I. Glaucon’s Thesis

A. Which one has a better life: a just or an unjust person?

B. Possible Origins of Justice (acc. to Glaucon)

C. Glaucon’s two extremes and the mean:




Do Wrong without Punishment

Pass Law

Be Wronged without Retaliation

II. Glaucon’s Explanation:

A. Suffering wrong so far exceeds in badness the good of inflicting it, people come to an agreement neither to inflict injury nor suffer it.

B. Therefore, laws that people pass are called just.

III. Glaucon’s Challenge to Socrates

A. Gyges’ Ring

1. Point: any man would do injustice if he had a ring that made him invisible, so he could get away with bad actions.

B. Two Rings

1.. The unjust man would carry on

2. The just man could not resist injustice b/c “people believe in their hearts that injustice is more profitable to the individual than justice.”

C. Glaucon and Two Lives

Thoroughly Unjust Man  v. Thoroughly Just Man

All wrongs hidden

All righteousness secret

Reputation intact

Reputation in shambles



Gods are appeased

Gods inflict suffering

Escape human detection

No escape

Glaucon’s Challenge to Socrates: Under this scenario, prove to us that justice is better than injustice

IV. Socrates’ Answer:

        All Humans


Soul Living Model Justice Injustice
Appetite Many-Headed Beast Tames Feeds
Spirited Lion Tames Feeds
Reason Man Feeds Neglects
           Results: Happiness Misery

A. Argument: / explanation

1. To do injustice, even without getting caught and with immediate profit to appetite, damages the soul.

2. A damaged soul causes misery.

3. So injustice causes misery, not happiness.

4. To do justice benefits the soul.

5. A healthy soul causes happiness, not misery

6. Therefore, a just person is happier and so has a better life than an unjust person. Book 9 of the Republic

V. Answer (to Thrasymachus):

A. The function of each thing (eyes, ears, horses, pruning knife) is to do what it alone can perform or can perform better than anything else.

1. E.g. a pruning knife performs better for pruning than a kitchen knife does

B. Each functioning thing has its own excellence, which is its proper and right function or when it functions properly.

C. By the way this is “virtue” ethics: virtue = excellence

D. Each thing functions badly if it has a defect (or vice).

E. This is true for all things, even a soul.

F. A soul functions in excellence when it lives well, without defect or vice, and this is justice.

G. The opposite of F is injustice.

H. Therefore, a just person lives a better life and is happier (an inner state) than an unjust person.


Plato the Soul Man

ARTICLES IN SERIES (alphabetical order)

Aristotle’s Virtue Ethics

Clifford’s Ethics of Belief

Descartes’s Meditations I and II

Hick’s Evil and God of Love

Hume’s Argument against Design

Hume’s Theory of Knowledge

James’s Will to Believe

Kant’s Ethics

Locke’s Theory of Knowledge

Mill’s Ethics

Nietzsche’s Madman and the Death of God

Paley’s Watchmaker and Design Argument

Plato the Soul Man

Plato’s View of Justice and the Soul

Rachels’s Moral Objectivism

Ryle’s Category Mistake

Sartre’s “Existentialism and Humanism”

Socrates’s “Apology”


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s