a method of working out the sum total of pleasure and pain produced by an act, and thus the total value of its consequences;sketched by Bentham in chapter 4 of his Introduction to the Principles of Morals and Legislation 1789.
When determining what action is right in a given situation, we should consider the pleasures and pains resulting from it, in respect of their
propinquity, (closeness or relation to the world)
fecundity (the chance that a pleasure is followed by other ones, a pain by further pains),
purity (the chance that pleasure is followed by pains and vice versa), and
extent (the number of persons affected).
We should next consider the alternative courses of action: ideally, this method will determine which act has the best tendency, and therefore is right. Bentham envisaged the calculus could be used for criminal law reform: given a crime of a certain kind it would be possible to work out the minimum penalty necessary for its prevention.
This is, in the utilitarian view of philosophy, the way to determine an action with the most good, which would therefore be the correct action. I agree with this philosophy for the most part. Although I must say that at this point philosophy seems largely useless, albeit interesting.
I should come up with a number scale for determining the correct action. Make that scale real math. even if the scale was only arbitrary. More on that later.