It befits youth as the age of passion and of errors.

In the old it is no virtue, as they should do nothing to be ashamed of (IX.).
Book Fifth (the first of the so-called Eudemian books), treats of Justice, the Social virtue by pre-eminence.

Justice as a virtue is defined, the state of mind, or moral disposition, to do what is just.
The question then is--what is the just and the unjust in action?
The words seem to have more senses than one.

The just may be (1) the Lawful, what is established by law; which includes, therefore, all obedience, and all moral virtue (for every kind of conduct came under public regulation, in the legislation of Plato and Aristotle).

Or (2) the just may be restricted to the fair and equitable as regards property.