Since happiness is based on virtue, we should try to understand the nature of virtue better in order to understand the nature of happiness better. Also, it is thought that the true student of Politics should have studied virtue if he is to make the citizens obedient to the laws. The lawgivers of the Cretans and the Spartans are good examples of what I mean. So if, like we said at the beginning, we are, in a way, studying Politics, then that means turning to study virtue will fit in with our goals.

Let us say again what we are specifically after here is what it is that makes human beings excel in what they do; our study is of human virtue. And by human virtue, we do not mean that of the body, but rather that of the soul. Happiness, we have said, is an activity of soul. Based on this, we say the student of politics must study and understand the human soul, if they are to understand human virtue. Think about it: if you were to heal the eyes or the body as a whole, then you would have to know about the eyes or the body. We know that even the best doctors take a lot of trouble to build up what they know about the body. Well, in Politics there is even more at stake than in Medicine, and so the student of Politics must put in time studying the soul, though just enough and they should not put in more effort going into more detail than what is called for here.

Elsewhere some people have put forth some thinking about the soul which is decent enough, and in this next part we will pick it up.

There are two parts of the soul. One uses reason and is called rational. The other does not and is called irrational. Whether or not the parts can really be separated and set apart from each other or if it is only possible to tell the difference in our minds -- well, that is not important to what we will go over, so do not worry about it.

Now, about the irrational part, we can divide that one up into further pieces. One of those pieces will be something that is found in all living things, plants and animals. I mean here, the thing it is by which life is able to take in food and grow. We call this the nutritive faculty. By faculty, we mean something that has a special ability to do something and is in charge of getting it done. One faculty we have is the one that takes the food we eat and gets nutrition out of it for our bodies (nutritive faculty).

Human beings do not achieve greatness through their nutritive faculty. You can tell this by the fact that it seems to do most of its work while we are asleep, while goodness and badness are seen least of all in sleep. (And this why we have the saying that the happy are no better than the wretched for half their lives, and this is natural enough because there are no good or bad experiences of life while asleep.) It might possibly be the case that the soul makes a little bit of difference here and the dreams of good people are better than those of others. Well, anyhow, we have said enough about the nutritive faculty, so let us keep going on over to the next part of the soul.

If we take a close look at it, we can see that there is another irrational part of the soul and yet it can at times agree with reason. Now, we praise people that have good reasoning, and even those who cannot always make good use of it because they lack in self-control. There is found in such people something that can be rebellous and resist against what would be reasonable. Think of someone with paralyzed limbs: they try to make a move to the right but wind up going to the left. It is the same way with the soul. This part of it does not go the right way. But while with the body it is pretty easy to see where there is a part that is not working right, inside our souls we cannot see so easy. How it can be that there is such a thing in our souls and just what makes it different from the other parts is not something we are going to get into here. We can say that it is not the case that this part will always go the wrong way. Sometimes it does go with reason; for someone with self-control, for instance, it will follow reason, and with sober people or with people known for being brave it is even more the case that the irrational part follows where reason goes, moreso than it does for ordinary people.

So we say again, the irrational part of the soul has two parts. The first one, the nutritive faculty, has nothing to do with reasoning. But this other part which hungers after things and desires things -- this still can have something to do with reason insofar as it will follow reason. And this is what we mean when say we went with our friends' advice or we followed the rules of our parents. We do not mean it like we remember some mathematics rule when we are figuring something out. We mean we get that irrational part in us to go along with good and reasonable things that people we respect have said we ought to follow.

Let us wrap up this section with a quick word about virtue. Virtue can, in the same way, be broken down into different kinds. We say that from some virtues come good thinking (intellectual virtues) and from other virtues come good action (moral virtues). Being someone that gives help where needed or someone that shows us how to have a good time without going too far -- these are moral virtues. Being someone that knows something about everything or someone that has lots of good advice for everyday life -- these are intellectual virtues. Intellectual and moral are different. When we talk about someone's character we do not talk about what they know about this or that, but the type of person they are, how they typically act and we say good things about people that do good things. But we also say good things about the wise: it is good that they know so much and can find a good course to take and can give good counsel when called for.