The 'permitted to do' formulation avoids these counterexamples because enough people voluntarily choose to have children, so permitting childlessness does not threaten species survival

The most common indirect consequentialism is rule consequentialism, which makes the moral rightness of an act depend on the consequences of a rule (Singer 1961). Since a rule is an abstract entity, a rule by itself strictly has no consequences. Still, obedience rule consequentialists can ask what would happen if everybody obeyed a rule or what would happen if everybody violated a rule. They might argue, for example, that theft is morally wrong because it would be disastrous if everybody broke a