Utilitarianism was Originally formulated by Jeremy Bentham in the 18th century, and fully developed by John Stewart Mill in the 19th. It Asserts that we should always act so as to produce the greatest ratio of good to evil for everyone concerned with our decision and As with all moral theories, has many strengths and weaknesses.
The prominant criticism of Utilitarianism is that it is extremely hard to predict the results of an action. The outcomes of all situations are hard to predict, so how can we possibly apply the rule of the greatest happiness for the greatest number if we do not know who will benefit most? It is also difficult to decide whether an outcome is morally good or bad. People have contrasting opinions on what they think is right or wrong and it depends on the individual who is making the decision. This causes problems because a thing that is good to one person may at the same time be bad to another, "One man's happiness is another man's pain."
Without an absolute definition of happiness, it is hard to arrive at a 'right' decision.
Another problem of Utilitarianism is the concept of time. Is long term or short term pleasure more valuable? For example, when deciding whether to take an ecstasy tablet at a club. Taking the pill may give you a lot of short-term pleasure, but in the long term, it may cause more harm than good. Not taking the tablet would involve fewer risks and would avoid potential pain. Even here, you cannot predict the results of your decision, as there is no way of telling the effect the ecstasy has on you until you have tried it. Not only is it hard to tell what will be the consequences in the "long run,"...