Classical Act Utilitarianism

“The creed which accepts as the foundation of morals ‘utility’ or the ‘greatest happiness principle’ holds that actions are right in proportion as they tend to promote happiness; wrong as they tend to produce the reverse of happiness. By happiness is intended pleasure and the absence of pain; by unhappiness, pain and the privation of pleasure.”

From J. S. Mill’s Utilitarianism

“That the assertion ‘I am morally bound to perform this action’ is identical with the assertion ‘This action will produce the greatest possible amount of good in the Universe’ has already been briefly shewn in Chap. I…. It [a morally obligatory action] can, therefore, be unique only in the sense that the whole world will be better, if it be performed, than if any possible alternative were taken.”

“Our ‘duty,’ therefore, can only be defined as that action, which will cause more good to exist in the Universe than any possible alternative. And what is ‘right’ or ‘morally permissible’ only differs from this, as what will not cause less good than any possible alternative.”

From §89 of G. E. Moore’s Principia Ethica

D1: The hedonic utility of an act, A, =df. the result of subtracting the total amount of pain that A would cause from the total amount of pleasure that A would cause were A performed.

D2: A is an alternative to B =df. A is another act that the agent of B can do at the time of B instead of B.

D3: An act, A, maximizes hedonic utility =df. no alternative to A has a higher hedonic utility than A has.

AU: An act is morally right if and only if it maximizes hedonic utility.

Some Competing Formulations of Act Utilitarianism:

AUx: An act, A, is morally right iff A produces more pleasure and less pain than any alternative to A.

GHP: An act, A, is morally right iff A produces the greatest amount of happiness for the greatest number of people.