Utilitarianism is an ethical theory developed in the modern period by Jeremy Bentham (1748-1832) and John Stuart Mill (1806-73) to promote fairness in British legislation during the eighteenth and nineteenth centuries when the interests of the upper classes tended to prevail and the sufferings of the lower classes were neglected. Utilitarianism is an ethical theory that calls for putting benevolence into action. Mill interprets the term utilitarianism as signifying any moral theory (the terms ethical and moral are used synonymously by Bentham and Mill,) in which acts are judged on the basis of their utility. Mill further specifies that there is no one conception of what constitutes utility and there is no implication of a sect. .
Explanation of Utilitarianism.
In Bentham's theory of Utilitarianism (1789), an action conforming to the principle of utility is right or at least not wrong; it ought to be done, or at least it is not the case that it ought not be done. But Bentham does not use the word 'duty' here. For Bentham, rights and duties are legal notions, linked with the notions of command and sanction. What we call moral duties and rights would require a moral legislator (a divine being presumably) but theological notions are outside the scope of his theory. To talk of natural rights and duties suggests, as it were, a law without a legislator, and is nonsensical in the same way as talk of a son without a parent. Apart from theoretical considerations, Bentham also condemned the belief in natural rights on the grounds that it inspired violence and bloodshed, as seen in the excesses of the French Revolution. .
In his Utilitarianism (1861), Mill made his description of this principle, three ideas are identified: (1) the goodness of an act may be determined by the consequences of that act. (2) Consequences are determined by the amount of happiness or unhappiness caused. (3) A "good" man is one who considers the other man's pleasure (or pain) as equally as his own.