Then on this view also justice will be admitted to be the having and doing what is a man's own, and belongs to him?
Very true.
Think, now, and say whether you agree with me or not. Suppose a carpenter to be doing the business of a cobbler, or a cobbler of a carpenter; and suppose them to exchange their implements or their duties, or the same person to be doing the work of both, or whatever be the change; do you think that any great harm would result to the State?
Not much.
But when the cobbler or any other man whom nature designed to be a trader, having his heart lifted up by wealth or strength or the number of his followers, or any like advantage, attempts to force his way into the class of warriors, or a warrior into that of legislators and guardians, for which he is unfitted, and either to take the implements or the duties of the other; or when one man is trader, legislator, and warrior all in one, then I think you will agree with me in saying that this interchange and this meddling of one with another is the ruin of the State.
Most true.
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 evil-doing?
Precisely.
And the greatest degree of evil-doing to one's own city would be termed by you injustice?
Certainly.