Act utilitarianism judges each individual action by whether it maximizes overall utility in that situation. Rule utilitarianism judges actions by rules whose general acceptance would maximize overall utility.
The Reasoning
Both theories are forms of consequentialism: moral rightness ultimately depends on consequences. They share the principle of utility, which requires maximizing well-being or happiness and minimizing suffering for everyone affected.
Their difference concerns the level at which consequences are assessed.
| Feature | Act utilitarianism | Rule utilitarianism |
|---|---|---|
| Main question | Which action maximizes utility in this case? | Which generally accepted rule maximizes utility? |
| Focus | Consequences of the particular act | Consequences of adopting or following a rule |
| Flexibility | Rules can be broken whenever utility increases | Acts normally follow utility-maximizing rules |
| Strength | Sensitive to circumstances | Supports consistency, trust and predictability |
| Objection | May permit injustice or rights violations | May become rigid or collapse into act utilitarianism |
Suppose lying would save an innocent person. An act utilitarian compares the consequences of this lie with truth-telling. A rule utilitarian instead asks whether a generally accepted rule permitting lies in such circumstances would create more utility than competing rules.
Act utilitarianism might permit punishing an innocent person if doing so prevents greater harm. Rule utilitarianism tries to avoid this by supporting rules protecting justice and individual rights, because societies usually gain utility when those rules are upheld.
A common misconception is that rule utilitarianism is simply deontology. It is not: its rules are justified by utility-producing consequences, not by intrinsic duties. However, adding exceptions whenever utility would increase may make rule utilitarianism collapse back into act utilitarianism.
Exam Technique
In IB Philosophy, define both positions, identify their shared consequentialist foundation, and apply both to the same example. For evaluation, judge whether rule utilitarianism answers objections to act utilitarianism or merely moves the calculation from acts to rules.
