The name given to the group of ethical systems that hold, with various modifications, that feelings of pleasure or happiness are the highest and final aim of conduct; that, consequently those actions which increase the sum of pleasure are thereby constituted right, and, conversely, what increases pain is wrong.
Philosophers commonly distinguish between psychological hedonism and ethical hedonism. Psychological hedonism is the view that humans are psychologically constructed in such a way that we exclusively desire pleasure. Ethical hedonism is the view that our fundamental moral obligation is to maximize pleasure or happiness. Ethical hedonism is most associated with the ancient Greek philosopher Epicurus (342-270 BCE.) who taught that our life's goal should be to minimize pain and maximize pleasure. In fact, all of our actions should have that aim: