A quasi contract created by law for reasons of justice without any expression of assent. A quasi-contract is the act of a person, permitted by law, by which he obligates himself towards another, or by which another binds himself to him, without any agreement between them.
A quasi contract is not contract at all. The commonest sample of the class is the relation subsisting between two persons one of whom has paid money to the other through mistake. The word quasi prefixed to a term in Roman law, implies that the conception to which it serves as an index is connected with the conception with which the comparison is instituted by a strong superficial analogy or resemblance. ….. [Maine’s Ancient Law, 1936 ed., p. 354]