Utilitarianism is the family of moral theories according to which the rightness of actions is determined solely by the sum total of wellbeing they produce.
All ethical theories belonging to the utilitarian family share four defining elements:
The original and most influential version of utilitarianism is classical utilitarianism. Classical utilitarianism accepts hedonism as a theory of welfare, the view that wellbeing consists of positive and negative conscious experiences. Moreover, classical utilitarianism accepts the total view of population ethics, according to which one outcome is better than another if and only if it contains a greater sum total of wellbeing, where wellbeing can be increased either by making existing people better off or by creating new people with good lives.
Utilitarianism has important implications for how we should think about leading an ethical life. Because utilitarianism weighs the wellbeing of everyone equally, it implies that we should make helping others a very significant part of our lives. In helping others, we should try to use our resources to do the most good, impartially considered, that we can. Since not all ways of helping others are equally effective, utilitarianism implies that we should carefully choose which problems to work on and by what means.
To do the most good they can, in practice, many utilitarians donate a significant portion of their income to address the world’s most pressing problems, devote their careers to doing good, and aspire to high degrees of cooperativeness, personal integrity and honesty.