Utilitarianism is a teleological and consequentialist theory as it focuses on whether an action is good or bad depending on the outcome, regardless of what the act may be. For example an act could be a horrible one, i.e. murder but if it brings about a good consequence it’s seen as a good act.
J. Bentham devised the greatest happiness principle which states that an action is right if it results in the greatest amount of pleasure for the greatest number of people “An action is right if it produces the greatest good for the greatest number”. Therefore his theory is quantitative because it focuses on numbers and not qualitative as he states that all pleasures are of equal quality. Bentham distinguishes between pain and pleasure. “The world has placed us under the governance of two sovereign masters. Happiness which is the `sovereign good’ and pain which is the `sovereign evil”. Therefore he created a calculus to judge the amount of pain and pleasure that a certain act brings about, it’s known as the Hedonic Calculus. Bentham’s Utilitarianism is known as ‘Act’, which is based on the reasoning that no action is intrinsically right or wrong. It depends on the individual, the circumstances and most importantly the outcome. This type of Utilitarianism is majorly flawed because it can virtually justify any act as long as it brings about more pleasure than pain, for example the 10 sadistic guards torturing and raping a woman, in this situation the pleasure of the guards clearly outweighs the pain of the woman therefore Act utilitarianism would justify their act.
J.S. Mill on the other hand is a Rule utilitarianist which is about agreeing general rules for society as a whole to follow that promote the greatest happiness for the greatest number of people, therefore individual situations where the rules are disobeyed will not be justified even if they bring about more