What did Plato say that was necessary to live a good life?

Plato said that in order to live a good life, three things are necessary:

- Knowledge of the Good: This is the highest form of knowledge, the understanding of what is truly good and right.

- Moderation: This is the ability to control one's desires and appetites, and to live in accordance with reason.

- Courage: This is the strength of character to stand up for what is right, even in the face of adversity.