Hedonism is a school of thought that argues that the pursuit of pleasure and intrinsic goods are the primary or most important goals of human life. A hedonist strives to maximize net pleasure (pleasure minus pain.) However upon finally gaining said pleasure, happiness may remain stationary.
Ethical hedonism is the idea that all people have the right to do everything in their power to achieve the greatest amount of pleasure possible to them. It is also the idea that every person's pleasure should far surpass their amount of pain. Ethical hedonism is said to have been started by Aristippus of Cyrene, a student of Socrates. He held the idea that pleasure is the highest good.