Aristotle argues that the correct approach in studying such controversial subjects as Ethics or Politics, which involve discussing what is true about what is beautiful or just, is to start with what would be roughly agreed to be true by people of good up-bringing and experience in life, and to work from there to a higher understanding.
Taking this approach, Aristotle begins by saying that the highest good for humans, the highest aim of all human practical thinking, is eudaimonia, a Greek word often translated as well-being or happiness. Aristotle in turn argues that happiness is properly understood as an on-going and stable dynamic, a way of being in action (energeia), specifically appropriate to the human "soul" (psuchē), at its most "excellent" or virtuous (virtue representing aretē in Greek). If there are several virtues the best and most complete or perfect of them will be the happiest one. An excellent human will be a person good at living life, who does it well and beautifully (kalos). Aristotle says that such a person would also be a serious (spoudaios) human being, in the same sense of "serious" that one contrasts serious harpists with other harpists. He also asserts as part of this starting point that virtue for a human must involve reason in thought and speech (logos), as this is an aspect (an ergon, literally meaning a task or work) of human living.
Aristotle believed that ethical knowledge is not only a theoretical knowledge, but rather that a person must have "experience of the actions in life" and have been "brought up in fine habits" to become good. For a person to become virtuous, he can't simply study what virtue is, but must actually do virtuous things.
As mentioned above, the Aristotelian Ethics all explicitly aim to begin with approximate but uncontroversial starting points. Aristotle's starting point is that everything humans do is aimed at some good, with some good higher than others. The highest human good that people aim at, he said, is generally referred to as happiness (Gk. eudaimonia - sometimes translated as "living well").
Aristotle asserted that popular accounts about what life would be happy divide into three most common types:
- a life dedicated to vulgar pleasure;
- a life dedicated to fame and honor;
- a life dedicated to contemplation.
To judge these, Aristotle uses his method of trying to define the natural function of a human in action. A human's function must include the ability to use reason or logos, because this is an essential attribute of being human. A person that does this is the happiest because he is fulfilling his purpose or nature as found in the rational soul.
The question of how to be happy therefore becomes a question of which activities of the human soul represent the highest excellence in using reason.
Aristotle proposed that we could accept it when people say that the soul can be divided into three parts: the Nutritive Soul (plants, animals and humans), the Perceptive Soul (animals and humans) and the Rational Soul (humans only).
The way in which Aristotle sketches the highest good for man involving both a practical and a theoretical side, with the two sides necessary for each other, is also in the tradition of Socrates and Plato, as opposed to pre-Socratic philosophy. As Burger (2008) points out (p. 212):- "The Ethics does not end at its apparent peak, identifying perfect happiness with the life devoted to theōria; instead it goes on to introduce the need for a study of legislation, on the grounds that it is not sufficient only to know about virtue, but one should try to put that knowledge to use." At the end of the book, according to Burger, the thoughtful reader is led to understand that "the end we are seeking is what we have been doing" while engaging with the Ethics (p. 215).