Moral universalism (or universal morality) is the meta-ethical position that some system of ethics, or a universal ethic, applies universally, that is, for "all similarly situated individuals, regardless of culture, race, sex, religion, nationality, sexuality, or other distinguishing feature. Moral universalism is opposed to moral nihilism and moral relativism. However, not all forms of moral universalism are absolutist, nor are they necessarily value monist; many forms of universalism, such as utilitarianism, are non-absolutist, and some forms, such as that of Isaiah Berlin, may be value pluralist.
Noam Chomsky states that
... if we adopt the principle of universality : if an action is right (or wrong) for others, it is right (or wrong) for us. Those who do not rise to the minimal moral level of applying to themselves the standards they apply to others -- more stringent ones, in fact -- plainly cannot be taken seriously when they speak of appropriateness of response; or of right and wrong, good and evil.
In fact, one of the, maybe the most, elementary of moral principles is that of universality, that is, If something's right for me, it's right for you; if it's wrong for you, it's wrong for me. Any moral code that is even worth looking at has that at its core somehow.
The source or justification of a universal ethic may be thought to be, for instance, human nature, shared vulnerability to suffering, the demands of universal reason, what is common among existing moral codes, or the common mandates of religion (although it can be said that the latter is not in fact moral universalism because it may distinguish between Gods and mortals). As such, models of moral universalism may be atheistic or agnostic, deistic (in the case of several Enlightenment philosophers), monotheistic (in the case of the Abrahamic religions), or polytheistic (in the case of Hinduism). Various systems of moral universalism may differ in various ways on the meta-ethical question of the nature of the morality, as well as in their substantial normative content, but all agree on its universality.
An enormous range of traditions and thinkers have supported one form or another of moral universalism, from the ancient Platonists and Stoics, through Christians and Muslims, to modern Kantian, Objectivist, natural rights, human rights and utilitarian thinkers. The United Nations' Universal Declaration of Human Rights is an example of moral universalism in practice.