Consequentialism provides one way of approaching questions about our values and about the systematic unity of the rules we follow in pursuing and protecting them. As the name indicates, the focus for this theory is on the consequences or outcomes of actions.
Consequentialism holds that what makes actions right or wrong are the consequences, or outcomes, of those actions. If you save a drowning man, or put out a fire in a burning building, then those actions are right because the outcome of the actions – a man didn’t drown, the building didn’t burn – are good. Likewise, if you steal something or cheat on your taxes, the actions are wrong because the outcomes – depriving someone of property, or failing to pay your fair share for government services – are bad.
J.S. Mill–Author of Utilitarianism
Different consequentialist theories make different claims about what in particular makes an outcome good or bad. The most well-known of these theories, the theory of Utilitarianism, holds that happiness is the only thing that is worthy of being pursued for its own sake, by everyone at all times. According to that theory, we should always act to maximize happiness, that is, to bring about the greatest possible happiness for the greatest number of people.