Psychological versus ethical hedonism
Hedonism is said to be 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 mostly associated with the ancient Greek philosopher Epicurus (342-270 BC) 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.
Eudaimonism or "happiness"
The word eudaimonism comes from the Greek word for happiness (eudaimonia), and refers to any conception of ethics that puts human happiness and the complete life of the individual at the center of ethical concern. This is essentially a technical term and has no popular equivalent, though sometimes humanism comes close.
Aristotle is the model eudaimonist, and really the founder of eudaimonism. Stoicism and Epicureanism are said to have turned their backs on eudaimonism because they didn't advocate individual fulfillment but only the lack of emotion or pain.
Pleasure is not considered to be the same as happiness, so hedonism is not the same as eudaimonism, the perception being that happiness is the highest good.
Kant was an important opponent of eudaimonism. He rejected the view that happiness is the highest good, and insisted that happiness can be an ingredient of the highest good only if it is deserved.
Contemporary hedonists are sometimes classed into egoistic and altruistic. The classification, however, is not quite satisfactory when applied to writers; because many hedonists combine the egoistic with the altruistic principle. The distinction, however, may conveniently be accepted with regard to the principles that underlie the various forms of the doctrine.
The statement that happiness is the primary purpose of conduct at once raises the question: whose happiness? To this egoism answers: the happiness of the agent; while altruistic hedonism replies: the happiness of all concerned; or, to use a phrase that is classic in the literature of this school, "the greatest happiness for the greatest number".
Other hedonistic perspectives
Hedonists have appropriated the term happiness as an equivalent to the totality of pleasurable or agreeable feeling. The same word is employed as the English rendering of the Latin beatitudo and the Greek eudaimonia, which stand for a concept quite different from the hedonistic one.
The Aristotelean idea is more correctly rendered in English by the term "well-being". It means the state of perfection in which man is constituted when he exercises his highest faculty, in its highest function, on its highest good. Because they fail to give due attention to this distinction, some writers include eudaimonism among hedonistic systems.
Epicurus and his philosophy of pleasure
In "A Letter to Menoeceus", one of his few surviving fragments, Epicurus gave advice on how to decrease life's pains, and explains the nature of pleasure. When it comes to decreasing life's pain, Epicurus explained how we can reduce the psychological anguish that results from fearing the gods and fearing death.
Concerning the nature of pleasure, Epicurus explained that at least some pleasures are rooted in nature and, as a rule, every pain is bad and should be avoided, and every pleasure is good and should be preferred.
There is a delicate relation between pain and pleasure. Every pain we have is bad, and we should minimize pain when possible; however, sometimes simply minimizing life's pains is sufficient to attain happiness, and we need to go a step further and actively increase pleasure. He argued that we should not pursue every possible pleasure; such as, when they produce more pain. He also, argued that the fewer desires we have, the easier it will be to experience happiness.
Christian philosophers rejected Epicurean hedonism
During the middle ages, Christian philosophers largely rejected Epicurean hedonism, which they believed was inconsistent with the Christian emphasis on avoiding sin, doing God's will, and developing the Christian virtues of faith, hope and charity.
Renaissance philosophers; such as, Erasmus (1466-1536) revived hedonism and argued that its emphasis on pleasure was in fact compatible with God's wish for humans to be happy. In his famous work Utopia (1516), British philosopher Thomas More (1478-1535) explained that "the chief part of a person's happiness consists of pleasure."
Like Erasmus, Thomas More defended hedonism on religious grounds and argued that, not only did God design us to be happy, but that He uses our desire for happiness to motivate us to behave morally.
More importantly, Thomas More distinguished between the pleasures of the mind, and pleasures of the body. He also argued that we should pursue pleasures that are more naturally grounded, so that we do not become preoccupied with artificial luxuries.
You will find words and definitions about hedonism or "pleasure" words by going to this hedono- link.