Moral philosophy takes two basic forms. One is morality that judges actions based on what consequences they have. This is known as teleology or consequentialism, and the most common form of consequentialism is Utilitarianism or Ethical Hedonism: The belief that the greatest good is to create as much happiness as possible for as many people as possible.
As a trope, Ethical Hedonism is known as For Happiness. Darker forms of utilitarianism are expressed by tropes such as Well-Intentioned Extremist, Totalitarian Utilitarian and Utopia Justifies the Means.
The other basic form is morality that judges actions based on the principles behind the actions. This is known as Deontology, and the most common form of Deontology is The Golden Rule. Darker forms of deontology are expressed by tropes such as Principles Zealot.
Maximize happiness, minimize suffering
Ethical Hedonism is not about getting total happiness for everyone: While such a goal would be great to achieve, it's too unrealistic to aim for. Instead, the goal is to create as much happiness as possible for as many as possible.
This may include creating destructive suffering as a necessary evil for the greater good. This doesn't have to lead all the way down to Utopia Justifies the Means, it can stop at some much earlier point along the Sliding Scale of Unavoidable Versus Unforgivable.
The thing is, no matter how evil or destructive a person is, a Ethical Hedonist believes that it is a bad thing to hurt that person. In itself, his happiness is just as important as anyone else's, and his suffering just as undesirable as anyone else's.
Abuse, violence and other violations are unacceptable in Ethical Hedonism, for two reasons. First, the act usually generate more suffering and deprivation of happiness (for the victim) than it creates happiness (for the abuser). Second, if abuse was accepted, then people would be more afraid and thus less happy. Thus, hurting abusers to make them stop is sometimes necessary, but if possible then it's better to redeem them without hurting them - two wrongs don't make one right.
In theory, a pure Ethical Hedonist has no problem with lies and deceit as long as it's done in a friendly and well-meaning manner. She would rather let her fallen comrades Die Happy than letting her honesty go too far. Of course, in most situations ethical hedonism consider lies and deceit to be a bad thing. But that's not because it's bad in principle but rather because it has a tendency to have unforeseen bad consequences.
Trying one's best for happiness is a required trait of any character who is an ethical hedonist without being a Straw Hypocrite or Hollywood Atheist. However, a character doesn't have to be philosophically inclined to be for happiness. The desire to make the world a better place through spreading or enabling happiness can come from anything from simple empathy to the religious worship of a deity that fits the concept.
The dark side
Given enough Insane Troll Logic, or simply disconnected from empathy, human dignity and the spirit behind the principle, ANY principle can be twisted into something vile. Either by interpreting "Happiness" in a way that the person receiving the "happiness" wouldn't agree with, or taking the principle to some narrow-minded extreme. With Ethical Hedonism, there are three main such subversions:
- We should maximize the average happiness. This can be done by killing off everyone who's unhappy.
- We should maximize the total happiness. Since even starving people are capable of happiness, we should reproduce as much as possible without any sense of sustainable development. (this fails to take into account the long term consequences of unsustainability, which will end up reducing happiness in the long run)
- Negative Utilitarianism: Instead of maximizing happiness, we should only focus on minimizing suffering. However, all living things suffer to some extent, so we should just put them out of their misery. (this assumes that death is not bad at all, and doesn't count as suffering)