The "Nicomachean Ethics" by Aristotle is the most influential book of the moral philosophy. From Kant to John Rawls, all philosophers have discussed the issue with Aristotle on the good life and on happiness.
To summarize, Aristotle raises the question of virtue: How should we act? How to live? The man, he said, must act according to reason. The moral of Aristotle is an ethics based on actions, the outcome (“good is the end”) override the intention, contrary to the kantian ethics.