In its wider meaning the term "discharge." with reference to contract law. implies that as a result of certain acts which have taken place after the contract was made, a contract which was once a valid and enforceable agreement has ceased to be enforceable. Discharge is thus to be distinguished from the defenses which were in existence when the contract was made, and which inhered in it from the outset, such as fraud, misrepresentation, mistake, undue influence, duress, want of contractual capacity, and the like.

The Roman law made consistent use of the simile of the knot whereby the parties were bound. The legal power of one party to enforce the contract against the other was the knot, the obligatio. The termination of the obligation was referred to as the untying of the knot, the solutio obligationis. The English law has never been as consistent in its nomenclature and terminology as the Roman law. It has ordinarily used the term "contract" to indicate a promise to which the law attaches an. obligation, and it has ordinarily used the term "discharge" to indicate the means by which valid contractual obligations were terminated. While included in the general subject of discharge, there are certain defenses, such as the Statute of Limitations,! and bankruptcy,2 which permit the defendant to interpose such defenses as bars to an action upon the contract, but which do not in themselves discharge the contractual obligation. In a narrower sense, the term "discharge" is sometimes used of discharge by voluntary agreement,3 or of discharge by a release under seal.4 In its wider sense, discharge as a noun includes performance or payment.5 Discharge as a verb seems to negative performance.6