Aristotle's conception of goodness is set forth in the opening sentence of this book. "Every art and every kind of inquiry, and likewise every act and purpose, seems to aim at some good; and so it has been well said that the good is that at which all things aim." This view appears obvious when we stop to consider the meaning of the word "good" as it is used in our everyday experience. We call an act good if it satisfies a particular need. The satisfaction of this need is then considered good if it is a means for satisfying some further need, and this in turn is good if it will satisfy still another one. Eventually this process must reach some point that is no longer a means for some further end but is an end in itself. This final end or goal of life is what Aristotle means by the highest good. It is the purpose of the study of ethics to discover the nature of this highest good and to find the appropriate means for its realization.
Because happiness is generally regarded as an end in itself rather than a means for achieving something else it would seem quite proper to call happiness the highest good or the ultimate goal for human life. However, this will not be sufficient unless we specify the kind of happiness that is most desirable, for nothing is more obvious than the fact that the nature of happiness varies with the type of person who experiences it and the same is true with regard to the methods by which it is obtained. Some people find happiness in the pursuit of sensual pleasures. Others find it in the pursuit of wealth or honor, and there are still others who find it in the activities that are associated with the contemplative life. Surely the kinds of happiness obtained by these different activities do not have equal value and it is for this reason that the student of ethics must give careful attention to the implications that are involved in each of them. It should also be noted that any adequate consideration of the good life must take into account the activities of life as a whole and these will involve his relationships to other members of the community in which he lives as well as those which pertain only to his individual welfare. The subject of ethics is indeed a complicated one. To deal with it successfully one needs maturity of judgment and familiarity with a wide range of relevant facts. The results of ethical inquiry cannot be established with the same degree of certainty that is possible in the more exact sciences. Nevertheless, reliable results can be obtained and these can be most helpful in guiding one toward a more adequate understanding of what it means to live at one's best.
In everyday life we speak of a thing being good when it serves the purpose for which it exists. For instance, we say that a knife is a good knife if it cuts well. A fruit tree is good if it produces the fruit that may reasonably be expected of it. Now the good of any object is to be found not in that which it has in common with other classes of objects but in that which is peculiar to its own class. It would be absurd to judge the goodness of a knife or a tree on the basis of some function for which neither of them was intended. If this is true with reference to physical objects the analogy holds for human beings. A good man is one who fulfills the purpose for which human beings exist and that purpose must be identified with those characteristics which distinguish man from other creatures. For Aristotle, this distinguishing characteristic is the ability to reason. The so-called lower animals have sensations, feelings, and that type of consciousness which includes these elements but man is the only animal that can make rational judgments and hence it is in the exercise of this unique capacity that his goodness is found. Critics of Aristotle's view may insist that man has other unique capacities along with his ability to reason. He is a social being who can participate in the intellectual life of the community. He has an aesthetic capacity which enables him to appreciate and enjoy the beautiful in the world around him. He has a sense of duty and moral obligation and he can worship and adore with religious zeal and devotion. Aristotle, too, recognizes all of these abilities but inasmuch as no one of them can function properly without the use of reason he includes them all as activities which may be guided and controlled by one's rational nature.
The fact that some activities are ends in themselves while others are primarily means for some end leads to an important distinction between intellectual virtues and moral virtues. These two kinds of virtue correspond in a way to the two elements of which the soul is composed. Intellectual virtues belong to the rational element and they consist of understanding, the acquisition of wisdom, the appreciation of beauty, and activities of a similar nature. Moral virtues have to do with the irrational element of the soul and they consist of bringing the appetites and physical desires under the control of reason. Aristotle does not consider the animal appetites which form a part of human nature as bad in themselves. It is only when they get out of control and there is either an excess or a deficiency that they are harmful to the soul. When they are regulated in accordance with the "golden mean" they make a positive contribution toward the good life. On the other hand the intellectual virtues are never in excess for their achievement always enhances the welfare of the entire soul.