Bentham's Utilitarianism

Jeremy Bentham was a British philosopher, jurist, and social reformer. He is regarded as the founder of modern utilitarianism.

Bentham sees that man is being governed by two feelings, this is pleasure and pain. These determine that which is good and evil for man. These are also the basis of the act of man, and these-pain and pleasure would be the fundamentals of the philosophy, utilitarianism.
The principle of utility "is the action that approves or disapproves an action whatsoever". By the principle of utility, it aims to help man to choose which would give him benefit. The principle of utility determines that which would give man more happiness, good, and pleasure, and negate that which would give him otherwise.
The perfect example of something that executes the principle of utility is the government. Since it upholds the betterment of the many, than the pleasure of the individual--this is demonstrated in law-making.
Legislators are bound to the principle of utility as they legislate, while for man--he acts with Calculus of Felicity in his mind. Considering the intensity, duration, trueness and closeness of an act. But these are only applicable for a given moment of time, but if a man has to consider a succession of events he must consider fecundity--where he thinks that a positive act would be followed followed by a positive act, and purity--where man thinks that an act will not be followed by a negative effect, or karma.
But for Bentham he asserts that this philosophy should be placed in context. The principle utilitarianism is nor always a good basis in judging the morality of an act. But the process of utilitarianism ail always be a good determiner of pleasure, profit, and advantage and also to tell which he should avert. Bentham considers that this principle maybe useless at times but he believes in the nature of man, he is innately born with pleasures of pain and this principle would always be useful to him.