Nicomachean Ethics I.9

For this reason also the question is asked, whether happiness is to be acquired by learning or by habituation or some other sort of training, or comes in virtue of some divine providence or again by chance. 

Those of you who have followed my earlier commentaries know that this question was one of Plato's regular subjects, and had been Socrates' as well. For example, the Meno -- which we looked at recently during our reading of the Anabasis -- comes down on the side that it must be a kind of divine gift, because the issues around treating virtue as a kind of knowledge that can be taught are so problematic and deep. If it were knowledge, you should be able to teach it; but even very good men often can't convey virtue to their sons. If it's knowledge, you should be able to define it if you know it; but it turns out to be devilishly hard to define even a relatively simple virtue like courage correctly (this is the subject of the Laches).

Socrates was apparently really bothered by this, and the puzzle was something that Plato worried about extensively also. It is the main subject of the Protagoras, where the two thinkers Socrates and Protagoras end up adopting the position that virtue is knowledge but can't be taught, or that it isn't knowledge but can be. It comes up in various forms in many other dialogues, such as the Lesser Hippias (which I wrote my Master's thesis partly about). In his major political works, the Republic and the Laws (see commentary on sidebar) Plato tried to deal with the problem practically. In the first of these, he decides that the problem is that not all that many people are rational enough to really learn these things, so that political power should be invested only in a select class of philosopher kings who would rule but be stripped of their families and raised with that class consciousness instead. In the second, he apparently abandons that idea, but instead suggests that virtue could be instilled by an elaborate system of social controls and laws, overseen by a secret police led by a hidden nocturnal council of the virtuous. Both of those ideas are totalitarian and implausible to the point of being ridiculous, but they were the best Plato could come up with after a lifetime of thinking about it. 

So this is a short section of Book One of the EN, but it's aimed at a huge problem that two of the greatest minds in history had been struggling with for both of their generations. Virtue doesn't seem to be knowledge, and obtaining it requires more than reading about it or having teachers instruct you. 

Aristotle has an answer to the problem that is highly satisfying. I've written about it many times here, so you all know how it goes. Happiness -- eudaimonia -- is an activity, so it is something you have to do.  Specifically, you have to engage in the practice of doing virtuous acts. Virtue -- aretḗ -- is both the excellence you will practically display by acting with practiced skill from having done such acts many times, and also the character you develop by doing these virtuous things. 

An example: the reason we still have Airborne school isn't because we're going to drop an army of paratroopers again; it's because it requires the practice of courage, as well as several other virtues. Getting into the habit of acting courageously will eventually make you a courageous person. Once you get there, it'll be pleasant to do what was terrifying before. Technical Rescue doesn't do paratrooper school, but it does require rappelling and rope rescue as its first discipline. It's the same thing more or less: you have to get used to stepping out into nothing with only your faith in the equipment you helped prepare. It is eventually quite fun.

Now if there is any gift of the gods to men, it is reasonable that happiness should be god-given, and most surely god-given of all human things inasmuch as it is the best. But this question would perhaps be more appropriate to another inquiry; happiness seems, however, even if it is not god-sent but comes as a result of virtue and some process of learning or training, to be among the most godlike things; for that which is the prize and end of virtue seems to be the best thing in the world, and something godlike and blessed.

It will also on this view be very generally shared; for all who are not maimed as regards their potentiality for virtue may win it by a certain kind of study and care. But if it is better to be happy thus than by chance, it is reasonable that the facts should be so, since everything that depends on the action of nature is by nature as good as it can be, and similarly everything that depends on art or any rational cause, and especially if it depends on the best of all causes. To entrust to chance what is greatest and most noble would be a very defective arrangement.

The answer to the question we are asking is plain also from the definition of happiness; for it has been said to be a virtuous activity of soul, of a certain kind. Of the remaining goods, some must necessarily pre-exist as conditions of happiness, and others are naturally co-operative and useful as instruments. And this will be found to agree with what we said at the outset; for we stated the end of political science to be the best end, and political science spends most of its pains on making the citizens to be of a certain character, viz. good and capable of noble acts.

It is natural, then, that we call neither ox nor horse nor any other of the animals happy; for none of them is capable of sharing in such activity. For this reason also a boy is not happy; for he is not yet capable of such acts, owing to his age; and boys who are called happy are being congratulated by reason of the hopes we have for them. For there is required, as we said, not only complete virtue but also a complete life, since many changes occur in life, and all manner of chances, and the most prosperous may fall into great misfortunes in old age, as is told of Priam in the Trojan Cycle; and one who has experienced such chances and has ended wretchedly no one calls happy.

Emphasis added. Happy children in our more usual sense of the term in natural English aren't what Aristotle means; one hopes that children will be happy in that sense as often as they can be. What he's talking about here is how a boy isn't capable of being 'a happy man,' with his children gathered about him and his accomplishments, perhaps a wife he has joined with in a long and happy marriage, good friends of the kind we were just discussing. That's the kind of completeness that he is describing here.