Final answer:
The statement is true; utilitarianism is an ethical theory that uses the greatest happiness principle as the basis for determining the morality of actions.
Step-by-step explanation:
The creed which accepts as the foundation of morals utility, or the greatest happiness principle, indeed holds that actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness. This is a core tenet of the ethical theory known as utilitarianism, which was developed by philosophers Jeremy Bentham and later expanded upon by John Stuart Mill. Utilitarianism is a form of consequentialism, which means it judges the morality of actions based on their outcomes, specifically the amount of happiness or utility they produce. In this context, utility is synonymous with happiness or well-being. Thus, the right action is the one that maximizes happiness or produces the most net happiness for the greatest number of people, taking into consideration both increasing happiness and reducing unhappiness.