That which makes the community, and brings men out of the loose state of Nature into one politic society, is the agreement that everyone has with the rest to incorporate and act as one body.
Gist of Idea
A politic society is created from a state of nature by a unanimous agreement
John Locke (Second Treatise of Government , 211)
Geography usually keeps commonwealths in place once they have been established, but some of them become disfunctional hell holes because they are trapped in perpetual disagreement.
Locke,John: 'Two Treatises of Government' [Everyman 1988], p.224