Equality (as distinct from social equality) plays a regulative role in moral theory insofar as it constrains the application of moral rules and principles; that is, moral rules and principles ought to be equally applicable to all people. Utilitarians,  for example, believe that everyone's happiness counts equally. No matter whether a person has a high income, good education, or was born into poorer circumstances, the utility of each person counts in the same way -- in proportion to the strength of the happiness involved. Kantian theory considers the categorical imperative -- a prohibition against making exceptions -- to be the main principle of morality. The immoral person considers himself or herself to be more valuable, morally speaking, than others, a kind of moral inequality. Such equality is called ‘equal moral consideration.’
    Equality also serves as a baseline in moral theory. For example, some social contract theorists believe that moral principles are more justified people who are equal would select them. Under this view, inequalities may be justified but only if inequality is an improvement over equality.