In the Nicomachean Ethics, Aristotle argues that the ultimate good is eudaimonia or happiness and that ergon, human function, determines what that happiness is. While some might argue that there can be more than one form of ultimate good besides happiness, Aristotle believes that not all ends are complete. Unlike happiness, wealth, for example, is not complete and therefore eudaimonia is the only ultimate good. To determine in which good or goods happiness consists, Aristotle asks what the ergon of a human being is and maintains that it consists in the activity of the rational part of the soul according to virtue. Aristotle also provides his vision of what the best life is and consists of, however, it is illogical to identify a single type of best life for everyone, since it should be related to each person in different ways. Furthermore, the life of study, which is the best life according to Aristotle, is not the only kind of life that will lead to happiness. The better life of someone who is sick versus that of someone who is poor will be different in terms of what it consists of and the happiness it will bring. Aristotle believes that eudaimonia or happiness is the ultimate good and that the best life is guided by rational contemplation; while it is true that happiness is the supreme good, Aristotle incorrectly claims that the best life is a life of study and provides an objective account of the good life that does not apply to everyone. While happiness is the ultimate good, Aristotle establishes the best life and incorrectly states that the life of study is the best life for all, but it is critical to first determine how Aristotle connects eudaimonia with human function and virtue. Aristotle believes that by asking what is the...... middle of the paper... the activity of the rational part of the soul in accordance with virtue. He believes that the human function is only that peculiar to us. Aristotle also presents a strong reason why happiness is the supreme good. Happiness is worthy of choice in itself and never for something else, therefore it is complete. Finally, Aristotle argues that the life of study is the best life for all human beings, yet there should be a single good that constitutes the purpose of every human being. He incorrectly argues that just because the gods are involved in the study, humans should also take part in such activity. Forgetting all the previous things he had said about virtues and habituation, Aristotle claims that only a life of study will bring happiness. While all humans should aim to achieve Aristotle's vision of eudaimonia or happiness, his beliefs about the best life are unrealistic..