enforce the promise. This particular rule of consideration forms the basis of the doctrine of privity of a contract, that is, only a party to a contract is permitted to sue upon that contract's terms. (Note that the doctrine of privity has been somewhat altered by the Contracts (Rights of Third Parties) Act 1999.) Therefore, consideration from the promisee was indulgent of the claim. Although consideration must move from the promisee, it does not necessarily have to move to the promisor. The promisee may provide consideration to a third party, if this is agreed at the time the parties contracted. The offeree must provide consideration, although the consideration does not have to flow to the offeror. For example, it is good consideration for person A to pay person C in return for services rendered by person B. If there are joint promisees, then consideration need only to move from one of the promisees. Pre-existing duties If the promisee provides what he was required by public law to do in any event in return for a promise, promised performance of existing duty is not good consideration. In Collins v Godefrey Godefrey promised to pay Collins for his giving of evidence. It was held that Collins could not enforce the promise as he was under a statutory duty to give evidence in any event. However, if the promisee provides more than what public duty imposes on him, then this is good consideration. In Ward v Byham a mother was under a statutory duty to look after her child. The ex-husband promised to pay her £1 a week if she ensured that the child was well looked after and happy. It was held that notwithstanding the statutory duty imposed on the mother, she could enforce the promise since the act of keeping the baby 'happy' provided additional consideration. Promising to perform a pre-existing duty owed to one's contracting party also fails to make good consideration. However this rule has been considerably narrowed by recent case law. The general rule is that if a creditor promises to discharge a debt in return for a fraction of payment, in paying the agreed fraction, the promisee is not providing consideration for the promise, as this is merely part performance of a contractual duty already owed.{{efn|Pinnel's Case was confirmed by Foakes v Beer}} Consequently, the debtor is still liable for the whole amount, as he cannot force