
Utilitarianism is a consequentialist theory: an action is right if and only if it produces the best overall balance of welfare across everyone affected. It treats every person's interests as equally important and asks only one question -- what does this action actually bring about?
- Consequences -- not intentions, not rules -- determine moral worth.
- Each affected person counts equally in the calculus of welfare.
- Act utilitarianism evaluates each action; rule utilitarianism evaluates the policies behind actions.
- Strong in triage, scale, and impartiality; weak when minorities can be sacrificed for majorities.
- Hidden costs and second-order effects (loss of trust, precedent, reputation) are easy to under-weight.

