Moral universalism in the context of "Ideal observer theory"

Cosmopolitanism is the idea that all human beings are members of a single community. Its adherents are known as cosmopolitan or cosmopolite. Cosmopolitanism is both prescriptive and aspirational, believing humans can and should be "world citizens" in a "universal community". The idea encompasses different dimensions and avenues of community, such as promoting universal moral standards, establishing global political structures, or developing a platform for mutual cultural expression and tolerance.

For example, Kwame Anthony Appiah articulates a cosmopolitan community where individuals from varying locations (physical, economic, etc.) enter relationships of mutual respect despite their differing beliefs (religious, political, etc.). In a looser but related sense, "cosmopolitan" is also used to describe places where people of various ethnic, cultural and/or religious backgrounds live together and interact with each other.

The Declaration of the Rights of Man and of the Citizen (French: Déclaration des droits de l'Homme et du citoyen de 1789), set by France's National Constituent Assembly in 1789, is a human and civil rights document from the French Revolution; the French title can be translated in the modern era as "Declaration of Human and Civil Rights". Inspired by Enlightenment philosophers, the declaration was a core statement of the values of the French Revolution and had a significant impact on the development of popular conceptions of individual liberty and democracy in Europe and worldwide.

The declaration was initially drafted by Marquis de Lafayette with assistance from Thomas Jefferson, but the majority of the final draft came from Abbé Sieyès. Influenced by the doctrine of natural right, human rights are held to be universal: valid at all times and in every place. It became the basis for a nation of free individuals protected equally by the law. It is included at the beginning of the constitutions of both the French Fourth Republic (1946) and French Fifth Republic (1958) and is considered valid as constitutional law.

Open society (French: société ouverte) is a term coined by French philosopher Henri Bergson in 1932, and describes a dynamic system inclined to moral universalism. Bergson contrasted an open society with what he called a closed society, a closed system of law, morality or religion. Bergson suggests that if all traces of civilization were to disappear, the instincts of the closed society for including or excluding others would remain.

The idea of an open society was further developed during World War II by the Austrian-born Jewish philosopher Karl Popper. Popper saw it as part of a historical continuum reaching from the organic, tribal, or closed society, through the open society (marked by a critical attitude to tradition) to the abstract or depersonalized society lacking all face-to-face interaction transactions.

Universal prescriptivism (often simply called prescriptivism) is the meta-ethical view that claims that, rather than expressing propositions, ethical sentences function similarly to imperatives which are universalizable—whoever makes a moral judgment is committed to the same judgment in any situation where the same relevant facts pertain.

This makes prescriptivism a universalist form of non-cognitivism. Prescriptivism stands in opposition to other forms of non-cognitivism (such as emotivism and quasi-realism), as well as to all forms of cognitivism (including both moral realism and ethical subjectivism).