The Greek philosopher Epicurus (341-271 B.C.) was a proponent of Hedonism, the theory that the point of one's actions was always to seek happiness.  The main goal in life, then, was attaining happiness. Based on this belief, a hedonistic theory of ethics was developed.  Actions, behaviors, and beliefs that led to one's happiness were morally good while those that led to one's unhappiness or pain were morally bad. 

At it's heart, hedonism is an ethical theory that considers only a person's own interests to be inherently important in a moral sense.  Other people only matter to the hedonist in as much as they affect him.  It might seem that, on this basis, an ethical theory based on hedonism would be a very shallow one.  This is not necessarily the case. 

"Give me black bread and watered down wine. The simplest pleasures are the easiest to obtain, the least likely to be taken away, and the healthiest."  This quote from Epicurus illustrates his view that a person who seeks happiness as their ultimate goal will attempt to live a long life of simple tranquility.  

Consider the costs of most of the things we normally associate with happiness.  To afford the wardrobe necessary to keep up with ever changing fads, the expensive luxury car or S.U.V., and the 4000 square foot house on the golf course, a person has to work very hard.  Does the superficial and ephemeral pleasure gained from this material wealth really counterbalance the effort taken to attain it?  Epicurus thinks it doesn't.