Virtues, according to Aristotle, are those strengths of character that promote 'eudomania' (human flourishing). A good action is a product of these virtues. A person is virtuous in so far as he acts with the goal of human flourishing in view.
Aristotle's theory revolves around character rather than around the actions themselves. For Aristotle, Virtue is something practiced and thereby learned - it is habit (hexis) which causes a person to choose the action that leads to flourishing in a given situation. This has clear implications for moral education, for Aristotle obviously thinks that you can teach people to be virtuous. To begin with our parents and teachers encourage us to be moral, but after some time we become a more or less instinctive moral people because doing the right thing has become second nature.
Everything is heading towards its own unique goal. Just as a knife fulfils its purpose by cutting well, human beings are fulfilled and happy when they're functioning well. We are already programmed with the "software" of moral virtues, but it is up to us to realize its full potential. We become moral by working at it, just as we learn to play the piano by practicing.
Virtue, Aristotle suggests, involves finding the 'mean' between the two extremes of excess and deficiency. Not mediocrity, but harmony and balance. If we achieve this, he thinks, then we will be psychologically content. For example, as good humans, we should try to be reasonably courageous, but not ridiculously reckless or absurdly timid. Apart from courage, the other moral virtues are listed as: temperance, liberality, magnificence, magnanimity, proper ambition, patience, truthfulness, wittiness, friendliness and modesty.
Moral virtues are connected with the desiderative and vegetative parts of the soul (irrational). Intellectual virtues, however, are connected with the scientific and calculative parts (rational) and are cultivated