Utilitarianism

Hedonism holds that there is some single features of actions or states of the world which motivates, or justifies, people in the pursuit of those states or actions, and further that this feature is roughly identical to the thing that we refer to, in common speech, as "pleasure". A nice theory, but it turns out to be wrong.

Utilitarianism drops the last requirement, and holds that there is something (call it "utility") that actions or states of the world have, and that actions are motivated or justified in terms of this something. Also a nice theory, also turns out to be wrong. (Unless you explicitly define "utility" so as to make it true, in which case it's true but vacuous.)

John Stuart Mill wrote a famous (and short) book called Utilitarianism, about Utilitarianism.

See also goodness and evil.