How we cite our quotes: (Book.Chapter.Bekker #s); all Bekker line numbers are approximate, since they are keyed to the original Greek.
Quote #7
Some voluntary things we do because we have chosen them, others we do though we have not chosen them: we choose all those that we deliberated about beforehand, and those not chosen are those not deliberated about beforehand. (5.8.1135b9-11)
It's important especially for lawgivers to understand what types of actions are voluntary and which are involuntary, Aristotle says. For one thing, it isn't always easy to determine this. Even when we can categorize an action one way or another, there are often circumstances that make our actions quite a mixed bag.
An action might be considered voluntary (i.e. having its origin within ourselves) but not be the result of pre-meditation or careful mulling over the consequences (i.e. deliberation). To call something truly voluntary, the key thing is choice: conscious deliberation about our course of action.
Quote #8
But if a person harms someone from choice, he acts unjustly; and it is in reference to these acts of injustice that he who does them is himself unjust, whenever the act is contrary to what is proportional or equal. Similarly too a person is himself just whenever he performs a just act, having chosen to do so...(5.8.1136a2-3)
Aristotle differentiates between a person who does an unjust act (but is not an unjust person) and one who does an unjust act and actually is unjust (and applies the same thinking to just acts).
It may seem like a lot of hair-splitting, but the distinction's important. We might do something wrong that ends in harm (i.e. running a stop sign), but it doesn't mean that we acted with the intention to harm. In this case, our actions are unjust, but we aren't. Choice (or prior deliberation) is crucial in determining such intent. And it's important to remember that we can't accidentally be just or unjust people.
Quote #9
It is manifest from this also who the equitable person is: he who is disposed to choose and to do these sorts of things and is not exacting to a fault about justice, but is instead disposed to take less for himself even though he has the law on his side, is equitable. (5.10.113734-1138a1)
Aristotle admits to us that the law isn't perfect where justice is concerned, especially in specific cases that require a judgment not exactly covered by law. Equity is the characteristic (or virtue) that allows a person to be equitable—or have greater concern for Justice (with a capital "J"—general justice)—rather than legalistic. It's clear who Aristotle thinks is a more superior person.