Book IV explained

What happens

Themes in this chapter

• Justice and Injustice

  Justice is defined as each part of the soul or state doing its own work, while injustice is the meddling of classes or parts, leading to ruin.

• Education and Virtue

  Virtue is described as the health and well-being of the soul, achieved through good practices and the preservation of law-implanted opinions.

• Knowledge and Ignorance

  Wisdom in the state resides in the smallest class of guardians who possess knowledge of the whole, distinguishing true counsel from mere technical skill.

Characters to notice

• Socrates

  Leads the discussion, drawing analogies between health of the body and virtue of the soul, and identifying the four virtues in the state.

• Glaucon

  Engages actively with Socrates, agreeing that the question of justice vs. injustice is now ridiculous, and follows the argument about the forms of vice and virtue.

Key passages

• “And the creation of health is the institution of a natural order and government of one by another in the parts of the body; and the creation of disease is the production of a state of things at variance with this natural order? True. And is not the creation of justice the institution of a natural order and government of one by another in the parts of the soul, and the creation of injustice the production of a state of things at variance with the natural order?”

  Health arises from a natural order among the body's parts, while disease results from disorder; similarly, justice arises from a natural order in the soul, and injustice from disorder.

  Socrates draws a direct analogy between bodily health and psychic justice, emphasizing natural harmony.

• “Then virtue is the health and beauty and well-being of the soul, and vice the disease and weakness and deformity of the same? True.”

  Virtue is the soul's health, beauty, and well-being, while vice is its disease, weakness, and deformity.

  This reinforces the idea that virtue is intrinsically beneficial, regardless of external rewards.

• “We know that, when the bodily constitution is gone, life is no longer endurable, though pampered with all kinds of meats and drinks, and having all wealth and all power; and shall we be told that when the very essence of the vital principle is undermined and corrupted, life is still worth having to a man, if only he be allowed to do whatever he likes with the single exception that he is not to acquire justice and virtue, or to escape from injustice and vice; assuming them both to be such as we have described?”

  If life is unbearable when the body is ruined, even with every pleasure and power, then life is not worth living when the soul is corrupted by injustice, even if one can do whatever one wants without acquiring virtue.

  Glaucon declares the question of justice's profitability ridiculous, as justice is essential to the soul's health.

• “I mean that courage is a kind of salvation. Salvation of what? Of the opinion respecting things to be feared, what they are and of what nature, which the law implants through education; and I mean by the words 'under all circumstances' to intimate that in pleasure or in pain, or under the influence of desire or fear, a man preserves, and does not lose this opinion.”

  Courage is the preservation of the law-imbued belief about what is truly to be feared, maintained despite pleasure, pain, desire, or fear.

  Socrates defines courage not as fearlessness but as steadfast adherence to correct moral education.

• “Then to do one's own business in a certain way may be assumed to be justice. Can you tell me whence I derive this inference? I cannot, but I should like to be told. Because I think that this is the only virtue which remains in the State when the other virtues of temperance and courage and wisdom are abstracted; and, that this is the ultimate cause and condition of the existence of all of them, and while remaining in them is also their preservative; and we were saying that if the three were discovered by us, justice would be the fourth or remaining one.”

  Justice is doing one's own work; it is the remaining virtue after wisdom, courage, and temperance are identified, and it underlies and preserves them all.

  Justice is presented as the foundational virtue that enables the others to function harmoniously.

• “Seeing then, I said, that there are three distinct classes, any meddling of one with another, or the change of one into another, is the greatest harm to the State, and may be most justly termed evildoing? Precisely. And the greatest degree of evildoing to one's own city would be termed by you injustice? Certainly.”

  When the three classes interfere with each other's roles, that is the greatest harm to the state and is properly called injustice.

  Injustice is defined as the transgression of class boundaries, disrupting the natural order.