There are several different schools of ethics.

People have a duty to comply with a set of universal principles that apply irrespective of the consequences of their actions

The guiding principle of conduct should be the greatest happiness or benefit of the greatest number.

People should act in their own best interests and an action is only right if it benefits the individual undertaking that action

Virtues such as charity and justice are dispositions to act in ways that benefit both the person possessing them, and society as a whole