Open society (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 British 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. Popper saw the classical Greeks as initiating the slow transition from tribalism towards the open society, and as facing for the first time the strain imposed by the less personal group relations entailed thereby. Whereas tribalistic and collectivist societies do not distinguish between natural laws and social customs, so that individuals are unlikely to challenge traditions they believe to have a sacred or magical basis, the beginnings of an open society are marked by a distinction between natural and man-made law, and an increase in personal responsibility and accountability for moral choices (not incompatible with religious belief). Popper argued that the ideas of individuality, criticism, and humanitarianism cannot be suppressed once people have become aware of them, and therefore that it is impossible to return to the closed society, but at the same time recognized the continuing emotional pull of what he called "the lost group spirit of tribalism", as manifested for example in the totalitarianisms of the 20th century. While the period since Popper's study has undoubtedly been marked by the spread of the open society, this may be attributed less to Popper's advocacy and more to the role of the economic advances of late modernity.