Society is indeed a contract†it becomes a partnership not only between those who are living, but between those who are living, those who are dead, and those who are to be born.

-Burke, Edmund
  Reflections on the Revolution in France.

Averbal contract isn't worth the paper it's written on.

-Goldwyn, Sam(uel) originally  Schmuel Gelbfisz
Attributed. Quoted in  A Scott Berg Goldwyn (1989).

Baseball is a Lockean game, a kind of contract theory in ritual form, a set of atomic individuals who assent to patterns of limited co-operation in their mutual interest.

-Novak, Michael
  The Joys of Sport, pt.1.

Every law is a contract between the king and the people and therefore to be kept.

-Selden,John
TableTalk (published1689).

The common wages of labour depends every where upon the contract usually made between those two parties whose interests are by no means the same†Masters are always and every where in a sort of tacit, but constant and uniform combination, not to raise the wages of labour above their actual rate.

-Smith, Adam
  An Inquiry into the Nature and Causes of theWealth of Nations, bk.1, ch.8.

The Social Contract is nothing more or less than a vast conspiracy of human beings to lie to and humbug themselves and one another for the general Good. Lies are the mortar that bind the savage individual man into the social masonry.

-Wells, H(erbert) G(eorge)
  Love and Mrs Lewisham, ch.23.