The open society is a concept originally suggested in 1932 by the French philosopher Henri Bergson, and developed during the Second World War by Austrian-born British philosopher Karl Popper.
Popper saw the open society as standing on a historical continuum reaching from the organic, tribal, or closed society, through the open society marked by a critical attitude to tradition, up to the abstract or depersonalized society lacking all face-to-face interaction transactions.
In open societies, the government is expected to be responsive and tolerant, and political mechanisms are said to be transparent and flexible. Advocates claim that it is opposed to authoritarianism.
Popper saw the classical Greeks as initiating the long 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. Growth-based industrial societies require literacy, anonymity and social mobility from their members — elements incompatible with much traditional-based behavior but demanding the ever wider spread of the abstract social relations Georg Simmel saw as characterizing the metropolitan mental stance.