Consideration
There are many definitions of considerations but the most readily accepted is that of (Lush J in Currie v Misa) “some right, interest, benefit accruing to one party or some for bivalence, detriment, lost or responsibility given, suffered or undertaken by the other”.
The price at which the promise is bought - (Dunlop v Selfridge)

There are 3 types of consideration; 1. Execute; that is a promise in exchange for a performance of an act. (reward) 2. Executory; this is where there is mutual promises between the two parties, where the obligation constituting the consideration is still to be performed. 3. Pas t; where the defendant makes a promise after the act was performed. Therefore, if A out of gratitude, promises B a reward for something B had already done before A’s promise B cannot sue on the promise. B’s consideration for the promise is already over and done with, in the past. The general rule is past consideration is not consideration. (Roscorla v Thomas)
Re: Mc Ardle: - however there are exceptions to the general rule; 1. Common Law Exception; past consideration will support a subsequent promise if the consideration was given at the request of the promisee. (Lampleigh v Braithwaite)
N.B. In the Privy Council decision of Pao on Lau Yit Long Lord Scarmanlay down the necessary conditions to apply; a. The act must have take place at the promiser’s request. b. The parties must have understood that the act was to be remunerated, wither by a payment or the conferment of some other benefit is legally enforceable. c. The payment or conferment of the benefit is legally enforceable.

2. Statutory Exceptions a. Limitation Act of 1990
Written acknowledgement of a statue bad debt would revive the debt.

b. Bill of Exchange act 1882
Negotiable instruments

3. Consideration must move from the promisee this means that the party who wishes to enforce a contract must show that he himself has provided some consideration for the other party’s promise. It would not suffice if the consideration has been provided by someone else. (Tweddle v Atkinson)

4. Consideration need not be adequate but must be sufficient. The question of adequacy in this context means that it need not constitute a realistic price for the promise it buys as long as it has some economic value.
N.B. Once a contract has been concluded the court would refrain from not withholding it merely because one of the parties made a bad bargain. The adequacy is for parties to consider at the time of making the agreement, not for the court when the agreement is sought to be enforced. (Thomas v Thomas), (Chappell v Nestle), (White v Bluett) 5. Sufficiency of Consideration
This means a form of consideration which the court recognizes as being valued. Consideration must have value in eyes of the law.
N.B. Traditionally doing something which is legally bound to do cannot amount as good consideration this can be looked at in 3 categories; a. Duty imposed by law: - this constitutes performance of an act which is easily authorized to do. The question therefore is whether this constitutes good consideration.
(Collins v Godefroy)
(Glassbrook v Glamorgan CC) – was good consideration
(Ward v Byham) – Not certain

b. Duty imposed by contract to a third party: - where duty is owed to a third party it’s performance can also be consideration for a promise by another. In that case the third party is getting something that he is entitled to. (Shadwell v Shadwell)

c. Duty imposed by a contract with the same party: - the general rule is that if A is bound to do something of virtue of a contract to B, performance of the duty cannot be consideration by B.

6. A request for extra payment for doing the same work is considered insufficient consideration.
(Stilk v Myrick) – was not sufficient consideration (Hartley v Ponsonby) – consideration was accepted

7. Part payment of debt: - the general rule is that part payment of a debt will not discharge the duty to pay the full sum. (Pinnel’s case 1602) The House of Lords (Foakes v Beer) confirm the rule in Pinnel’s case. Exception to the general rule in Pinnel’s case;

a. Where the promise to accept a smaller sum in full settlement is made by deed or is returned for consideration. b. Where the original claim was un-liquidated or disputed in good faith. c. Where the debtor does something different. i.e. where payment is made by creditor’s request; i. At an earlier time ii. At a different place iii. At a different method ( D.C. Builders v Rees) iv. Where payment is made by a third party (Hrachand Punamchand v Temple)

8. Promissory Estoppel: - is an equitable doctrine in which came about to mitigate the harshness of the doctrine which was first recognized in the case of Hughes v Metropolitan Railway Co. The doctrine was restated in Central London Property Trust Ltd. v High Trees House, where Lord Denning promulgated a modern version of the doctrine. There are four main requirements;

a. There must be a clear and unambiguous promise. (Woodhouse A.C. Israel Cocoa Ltd v Nigerian Product Marketing Co Ltd (1972)) b. The debtor should rely on that promise altering his legal promise in some way. There is some conflict as to whether the debtor must suffer some detriment or not. In Alan v El Nasr Export 1972, Lord Denning stated that detriment was not required it was held that detriment was necessary. c. It must be inequitable for the promiser to go back on his promise and insist. ( D.C. Builders v Rees) d. The doctrine does not create new causes of action where none existed before. It only prevents a party from in stricting against legal rights therefore; the doctrine is to be used as a shield and a sword.
N.B. Is the doctrine suspensory or distinct in its effect? The court us yet to conclude this, in High Trees case, Lord Denning stated that a promiser giving due notice might resume his rights. (Tool Metal Manufacturing v Tungsten), (Ajayi v RT Briscoe (Nigeria) Ltd)