Nicomachean Ethics is a philosophical inquiry into the nature of the good life for a human being. Aristotle begins the work by positing that there exists some ultimate good toward which, in the final analysis, all human actions ultimately aim. The necessary characteristics of the ultimate good are that it is complete, final, self-sufficient and continuous. This good toward which all human actions implicity or explicitly aim is happinessin Greek, "eudaimonia," which can also be translated as blessedness or living well, and which is not a static state of being but a type of activity.
To discover the nature of human happiness it is necessary to determine what the function of a human being is, for a person's happiness will consist in fulfilling the natural function toward which his being is directed. This natural function must be something which is specific to human beings, which is essential to being human. A person is primarily his intellect. While the spirited and desiring parts of the soul are also important, the rational part of the soul is what one can most properly consider a person's identity. The activity which only human beings can perform is intellectual; it is activity of the highest part of the soul (the rational part) according to reason. Human happiness, therefore, consists in activity of the soul according to reason. In practical terms, this activity is expressed through ethical virtue, when a person directs his actions according to reason. The very highest human life, however, consists in contemplation of the greatest goods. More will be said later on this topic, which is the culmination of the Ethics.
Ethical virtue "is a habit disposed toward action by deliberate choice, being at the mean relative to us, and defined by reason as a prudent man would define it." Each of the elements of this definition is important. Virtue is not simply an isolated action but a habit of acting well. For an action to be virtuous a person must do it deliberately, knowing what he is doing, and doing it because it is a noble action. In each specific situation, the virtuous action is a mean between two extremes. Finally, prudence is necessary for ethical virtue because it is the intellectual virtue by which a person is able to determine the mean specific to each situation.
Before going into a discussion of the individual virtues it is necessary to clarify what it means for an action to be voluntary, since only voluntary actions can be virtuous. For an action to be involuntary, there must be some external principle causing the action and the person must not contribute anything to the action. An action done through fear is only partially voluntary, and an action done through ignorance may have different degrees of voluntariness, depending on whether or not the person would have wanted to do it if he had known what he was doing. A proper intention is necessary for virtuous action. Intention is not a desire, a wish or an opinion. It is something previously deliberated upon, and is formed with reason or thought. One can only intend something which one has the power to do.
The first virtue discussed is bravery. It is a mean between rashness and cowardice. A brave man is one who faces and fears what he should for the right reason, in the right manner and at the right time. A brave man performs his actions for the sake of what is noble. A brave man is thus one who is fearless in facing a noble death.
The next virtue is temperance. It is a mean with regard to bodily pleasures. The intemperate man desires pleasurable things and chooses them because they are pleasurable; he is pained when he fails to get what he desires. A temperate man is moderately disposed with regard to pleasures and pains. He loves such pleasures as right reason dictates. Temperance keeps the desiring part of the soul in harmony with reason.
Generosity is the third virtue which Aristotle examines. With regard to property, generosity is a mean between wastefulness and stinginess. A generous man will give to the right person, the right amounts and at the right times. He will also take proper care of his possessions. Generosity does not depend on the quantity of the giving but on the habit of the giver, which takes into account the amount which the giver himself has and is able to give away.
The next virtue is munificence, which consists giving large amounts for suitable occasions. The deficiency of this virtue is called meanness and the excess is ostentation. A munificent man spends gladly and lavishly, not calculating costs, but always for a noble purpose.
Magnanimity, the fifth virtue Aristotle discusses, is one of the peaks of virtue. A magnanimous man claims and deserves great honors. Someone who deserves honors but doesn't claim them is low-minded, and someone who claims honors but doesn't deserve them is vain. It is better to be vain than low-minded, because vanity will be naturally corrected by life experience. A magnanimous man is great in each of the virtues, and is a sort of ornament of virtues because he shows how good a virtuous life is.
The next virtue concerns honor, specifically small and medium honors. It is a mean between too much and too little ambition which can be described as right ambition.
The virtue that is a mean with respect to anger is good temper. The excesses are irascibility or bitterness. If one is irascible he gets angry quickly and retaliates but then forgets about it. Someone who is bitter holds anger for a long time. A good tempered man is one who becomes angry on the right occasions, with the right people, at the right time and for the right length of time.
The next three virtues are friendliness, the mean between flattery or obsequiousness and quarrelsomeness; truthfulness, the mean between boastfulness and self-depreciation, and wit, the mean with regard to humor and amusement. Wit entails saying the right things in the right manner and also listening to things properly.
The last virtue, which unites and orders all of the other virtues, is justice. Justice can also be considered in a more specific sense, as one of the virtues. Both justice in the specific sense and justice as the whole of virtue are defined in relation to other people, but justice in the specific sense is concerned with honor, property, safety and similar things, while justice in the larger sense is concerned with virtue as a whole. Another subset of justice is distributive justice. Justice (in the narrow sense) is a mean between two extremes of unfairness. What is just in distribution should be in some way according to merit, but not all agree what that merit should be. Advocates of mob rule say that this merit is freedom, oligarchs say that it is wealth, others say that it is good ancestry and aristocrats say that is virtue.
Natural justice is that which is just in all times and places. Conventional justice is that which is made up of laws and customs. All laws are to some extent just because any law is better than no law, but are always at least slightly flawed in that they must be formulated universally and cannot take into account all specific circumstances. As a result, a judge should rule in accordance with the intention of the lawmaker or the idea behind the law when the law does not seem to properly fit the situation.
Prudence is the intellectual virtue of practical reason. It is concerned with human actions and gives a person the ability to choose what the virtuous mean is in specific situations. Acquiring prudence requires time and experience. Prudence and ethical virtue are both necessary for one another.
Continence and incontinence are concerned with bodily pleasures just like temperance and intemperance, but are distinct from them. The incontinent man is disposed to do what he knows is bad because of his passions. The continent man knows that his desires are bad but does not follow them because of reason. The difference between continence and temperance lies in the fact that for a temperate man his desires are in line with his reason.
Friendship is a necessary part of the good life. There are three types of friendship: friendship based on usefulness, friendship based on pleasure and friendship based on virtue. Only the last type is genuine friendship. Friendships based on usefulness and pleasure tend not to be very enduring, since they only last as the long as each party derives the usefulness or pleasure he desires from the relationship. Friendship based on virtue is based on wishing the good for the other person. This genuine friendship is necessary for self-knowledge and helps both of the friends to grow in virtue. Friendship presupposes justice and goes beyond it. The virtue of a friend is to love. The relationship one has with a friend is like the harmonious relationship between the different parts of the soul of a virtuous man.
In spite of what many philosophers may say, pleasure is a good. It perfects actions. The goodness of pleasure is determined by the goodness of the action which it accompanies. The highest good, happiness, must also involve pleasure.
Man's highest action and most complete happiness is a life of contemplation of the highest goods. Man's intellectual capacity is his highest capacity, and therefore his highest happiness resides in the use of that capacity. The life of contemplation is so sublime that it is practically divine, and man can achieve it only insofar as there is something divine in him. Contemplation is the action which best fulfills all the qualifications that the ultimate good should have, because it is the most continuous, complete and self-sufficient of all actions.
For most people, mere exhortation will not be enough to make them act virtuously. Consequently, good laws are necessary in order to make people virtuous. Laws and proper education are necessarily especially for the young, in order to train their passions and desires to be in accord with reason. Yet since such a great number of men are not virtuous, laws are necessary not just for the young, but for everyone.