One swallow does not make a summer, nor does one day; and so too one day, or a short time, does not make a man blessed and happy.

For Aristotle, a thing is best understood by looking at its end, goal, or purpose (telos). For instance, the end of a knife is to cut, and it is by grasping this that one best understands what a knife is; the end of medicine is good health, and it is by grasping this that one best understands what medicine is (or ideally should be). If one does this for some time, it soon becomes apparent that some ends are subordinate to higher ends, which are themselves subordinate to still higher ends.

If, then, there is some end of the things we do, which we desire for its own sake (everything else being desired for the sake of this) … clearly this must be the good and the chief good. Will not the knowledge of it, then, have a great influence on life? Shall we not, like archers who have a mark to aim at, be more likely to hit upon what is right?

The science that has for object the chief good, and whose end therefore includes that of all the others, is none other than the political art. To obtain the chief good for one person is fine enough, but to obtain it for the state is finer and more godlike. In inquiring into the chief good, care must be taken not to be too precise: fine and just actions admit of much variety and fluctuation of opinion, and ‘it is the mark of an educated man to look for precision in each class of things just so far as the nature of the subject admits’.

People agree that the chief good is happiness (eudaimonia), but the many and the wise disagree as to its nature. The many and vulgar identify happiness with sensual pleasure, but a life of sensual pleasure is no better than that of a beast. People of superior refinement and active disposition identify happiness with honour, but honour is merely a mark of virtue, and one that is reliant upon the recognition of others. Neither can happiness be identified with virtue itself, for then happiness would be compatible with a lifetime of sleep or inactivity or with the greatest sufferings and misfortunes.

According to Plato there is such a thing as the Form of the Good in which all good things share. However, this notion should be rejected as ‘piety requires us to honour truth above our friends’. Aristotle raises eight objections to the Theory of the Forms, but claims that this is not the place to investigate it. He revisits the subject in the Metaphysics.

Returning to the search for the chief good, a goal that is an end in itself is more worthy of pursuit than one that is merely a means to an end, and a goal that is never a means to an end but only ever an end in itself is more worthy of pursuit than one that is or can be both.

Now such a thing happiness, above all else, is held to be; for this we choose always for self and never for the sake of something else, but honour, pleasure, reason, and every virtue we choose indeed for themselves (for if nothing resulted from them we should still choose each of them), but we choose them also for the sake of happiness, judging that by means of them we shall be happy. Happiness, on the other hand, no one chooses for the sake of these, nor, in general, for anything other than itself.

All well and good, but what does happiness actually consist in? It is by understanding the distinctive function of a thing that one can understand its essence. For instance, one cannot understand what it is to be a gardener unless one can understand that the distinctive function of a gardener is ‘to tend to a garden with a certain degree of skill’. Whereas human beings need nourishment like plants and have sentience like animals, their distinctive function is their unique capacity to reason. Thus the Supreme Good, or Happiness, for human beings is to lead a life that encourages the exercise and development of reason and the practice of virtue. Happiness resides not so much in the possession as in the practice of reason and virtue, for just as it is not the strong and beautiful but those who compete well who win at the Olympic Games, so it is not the wise and virtuous but those who act well who win – and rightly win – the noble and good things in life. Their life is also more pleasant, as virtuous actions are pleasant by nature, and all the more pleasant still to the lover of virtue.

Now for most men their pleasures are in conflict with one another because these are not by nature pleasant, but the lovers of what is noble find pleasant the things that are by nature pleasant; and virtuous actions are such, so that these are pleasant for such men as well as in their own nature. Their life, therefore, has no further need of pleasure as a sort of adventitious charm, but has its pleasure in itself.

A person’s good or bad fortune can play a part in determining his happiness; for instance, happiness can be affected by such factors as material circumstances, social position, and even physical appearance. Yet, by living life to the full according to his essential nature as a rational being, a person is bound to become happy regardless of his good or bad fortune. For this reason, happiness is more a question of behaviour and of habit – of excellence and of virtue – than of luck. A person who cultivates reason and who lives according to rational principles is able to bear his misfortunes with equanimity, and thus can never be said to be truly unhappy. Even the greatest misfortunes can be borne with resignation, not through insensibility to pain but through nobility and greatness of soul.

With regard to the soul, it comprises a rational and an irrational part. The irrational part has a vegetative element that is concerned with nutrition and growth, and an appetitive element that contains a person’s impulses and that more or less obeys the rational part. If the rational part is strong, as in the virtuous person, it is able to exert a greater degree of control over the appetitive element of the irrational part. Similarly, there are two kinds of virtue, one that pertains to the intellect and that consists in philosophic and practical wisdom (dianoetic virtues), and another that pertains to the character and that consists in liberality and temperance (ethical or moral virtues). A person may be praised for either or both kinds of virtue.

Adapted from Aristotle’s Universe: A Primer on Aristotle