Ethics is a major branch of philosophy, encompassing right conduct and good life. It is significantly broader than the common conception of analyzing right and wrong. A central aspect of ethics is "the good life", the life worth living or life that is simply satisfying, which is held by many philosophers to be more important than moral conduct.

Socrates

Socrates was one of the first Greek philosophers to encourage both scholars and the common citizen to turn their attention from the outside world to the condition of man. In this view, Knowledge having a bearing on human life was placed highest, all other knowledge being secondary. Self-knowledge was considered necessary for success and inherently an essential good. A self-aware person will act completely within their capabilities to their pinnacle, while an ignorant person will flounder and encounter difficulty. To Socrates, a person must become aware of every fact (and its context) relevant to his existence, if he wishes to attain self-knowledge. He posited that people will naturally do what is good, if they know what is right. Evil or bad actions, are the result of ignorance. If a criminal were truly aware of the mental and spiritual consequences of his actions, he would neither commit nor even consider committing them. Any person who knows what is truly right will automatically do it, according to Socrates. While he correlated knowledge with virtue, he similarly equated virtue with happiness. The truly wise man will know what is right, do what is good and therefore be happy.

Aristotle

main: Aristotelian ethics Aristotle posited an ethical system that may be termed "self-realizationism". In Aristotle's view, when a person acts in accordance with his nature and realizes his full potential, he will do good and be content. At birth, a baby is not a person, but a potential person. In order to become a "real" person, the child's inherent potential must be realized. Unhappiness and frustration are caused by the unrealized potential of a person, leading to failed goals and a poor life. Aristotle said, "Nature does nothing in vain." Therefore, it is imperative for persons to act in accordance with their nature and develop their latent talents, in order to be content and complete. Happiness was held to be the ultimate goal. All other things, such as civic life or wealth, are merely means to the end. Self-realization, the awareness of one's nature and the development of one's talents, is the surest path to happiness.

Aristotle asserted that man had three natures: vegetable (physical), animal (emotional) and rational (mental). Physical nature can be assuaged through exercise and care, emotional nature through indulgence of instinct and urges, and mental through human reason and developed potential. Rational development was considered the most important, as essential to philosophical self-awareness and as uniquely human. Moderation was encouraged, with the extremes seen as degraded and immoral. For example, courage is the moderate virtue between the extremes of cowardice and recklessness. Man should not simply live, but live well with conduct governed by moderate virtue. This is regarded as difficult, as virtue denotes doing the right thing, to the right person, at the right time, to the proper extent, in the correct fashion, for the right reason.