A consideration, to be valuable and sufficient to support a contract, need not be adequate. A mutual promise, no matter how slight or trivial, or the payment of anything valuable to the promisor, is sufficient. Sometimes the inadequacy of the consideration tends to prove fraud in the making of the contract. When it is sought to avoid a contract on the ground of fraud, the inadequacy of the consideration may be considered in connection with the question of fraud. When fraud does not enter into the question, adequacy of the consideration is not questioned.
A sells B one hundred acres of land. The deed recites a consideration of one dollar. The deed of transfer is good and the smallness of the sum named does not affect the contract.
A promise to do something which one is already legally bound to do does not constitute a valuable consideration to a contract. A owes B one hundred dollars upon a promissory note. The note is past due and A fails to pay it. A promises to pay the note within ten days, on condition that B promise to give A a barrel of apples. B agrees. A cannot compel B to deliver the barrel of apples, nor has A any defense to the payment of the promissory note, since his promise to pay the note was a promise to do something he was already bound to do.
An illegal consideration does not support a contract. Any consideration contrary to established law is illegal. A promising to pay B one thousand dollars if B will burn C's barn is an example of illegal consideration.
10. Express and Implied Contracts. Some contracts expressly set forth the exact terms and conditions to be performed by both the contracting parties. For example, A makes a contract with B, by the terms of which, B is to construct a house for A. The contract is carefully prepared in writing, B is to receive five thousand dollars ($5,000.00) when the house is completed, and the contract contains provisions as to the details of the work and materials. Such a contract is called an express contract by reason of the terms having been expressly agreed upon by the parties. A contract need not be in writing to be express. The parties may enter into an express contract orally as well. Few contracts are made, however, in which some things are not implied. For example, in the contract for the building of a house it is practically impossible, or at least, is impracticable, to set forth in exact detail all the duties of the builder. For example, it would be unnecessary to give the size of the nails and number or quantity of same to be used. The contract impliedly requires the builders to use the proper size and quantity. A contract, however, in which the parties endeavor to set forth the principal things to be done, is known as an express contract.
An implied contract is one in which the parties do not expressly agree upon some of the important terms. A, a contractor, orders of B one thousand feet (1,000 ft.) of No. 1 white pine ship lap siding. The price is not mentioned. B delivers the lumber and A by implication is obliged to pay B the reasonable value thereof. The greater portion of business contracts are implied. An implied contract should not be confused with uncertain contracts. Uncertain contracts are void by reason of their uncertainty. A offers B one thousand dollars for five acres of land. B accepts the offer. In case the parties had no particular five acres of land in mind, the contract is void by reason of this uncertainty. The parties' minds did not meet on the question of what particular piece of land was to be transferred. In most implied contracts the article to be delivered is a part of a large quantity, and the particular part does not matter. Articles ordered from stock, such as groceries, shingles, slate, cement and lumber are common examples of this principal.
11. Unilateral and Bilateral, Executory and Executed Contracts. The mutuality or meeting of the minds, constituting one of the essential elements of the contract, may result from an express promise for a promise, or from an act performed in response to a promise. A promises to sell his automobile to B on the following day for five thousand dollars ($5,000.00). B promises to pay A five thousand dollars ($5,000.00) the following day. The mutuality consists of the mutual promises of A and B. Such contracts are known in law as bilateral contracts.
A promises to pay B one thousand dollars ($1,000.00) if B will move his house to the rear of A's lot. B, without promising to do so, moves the house. This act on the part of B constitutes the acceptance of the contract and completes the mutuality. Such contracts are known in law as unilateral contracts.
A contract to be performed in the future is known as an executory contract. A promises to pay B seventy-five dollars, if he will work on A's farm during the month of August of the following year. B accepts A's offer and promises to work for A as proposed. The contract is to be performed at a subsequent date, and constitutes an executory contract.