This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
Every contract is formed by offer and acceptance.1 Every offer for a simple contract must impose some consideration as well as include some promise, or the acceptance of the offer will not form a contract.2 Since the acceptance must conform to the offer,3 the acceptance must furnish the consideration, either by making a promise in return for the offeror's promise if the offer calls for acceptance by a promise, or by the performance of an act, if the offer calls for acceptance by the performance of an act. In the first case, the promise of the offeree is both acceptance and consideration. In the second case, the act of the offeree is acceptance, consideration and performance. Except for convenience, therefore, offer and acceptance could be considered in connection with consideration.4
6See Sec. 537.
7Burwell v. Chapman, 59 S. Car. 581, 38 8. E. 222.
8 See ch. LXIX.
9 Anonymous, Cary 5; Vez v. Emery, 5 Ves. Jr. 141; Tate v. Hilbert, 2 Ves. Jr. 111.
10Tate v. Hilbert, 2 Ves. Jr. 111. 11Tate v. Hilbert, 2 Ves. Jr. 111. 12Crawford's Appeal, 61 Pa. St. 52, 100 Am. Dec. 609.
13Whitehill v. Wilson, 3 Pen. & W. (Pa.) 405, 24 Am. Dec. 320.
14 See Sec. 514 et seq.
1 See ch. V.
2 See Sec. 537.
3 See Sec. 168 et seq.
Every contract must have a subject-matter, as well as consideration, if it is not under seal. This oft-repeated proposition is ele- mentary; but often as it has been used, little distinction has been made between subject-matter and consideration. Some authorities regard subject-matter as including everything bargained for on both sides; but it is more common to say or to assume that the subject-matter must exist on one side, and the consideration on the other. Where this view is entertained, there can be logically no distinction between the subject-matter and the consideration, for the right acquired by one may be regarded as either subject-matter or consideration, as we please, leaving the right acquired on the other side to be classed under the alternative. This is best illustrated where the contract consists of reciprocal promises, where it is a matter of arbitrary choice which we class as consideration and which as subject-matter. When a contract reaches the stage of litigation there is always a promise made by one party which the other party claims is valid and unperformed in whole or in part. If the question of a want of consideration is raised, the claim of the promisor is that no consideration exists for his promise. Whatever difficulty, therefore, may exist at the outset in determining which the consideration is, there is generally no difficulty in determining what constitutes the alleged consideration in a contract in litigation as, if any exists, it is the thing of value given in return for the promise which it is sought to enforce. It is customary in treating the subject to discuss question of the existence and reality of the right or forbearance in question under the head of consideration; while questions of legality, impossibility and the like are classed under subject-matter. To avoid a reduplication of topics, and to avoid departing unnecessarily from the customary arrangement of contract law, this order will be followed substantially;
4 See A Definition of Consideration, by John Barker Waite, 14 Michigan Law Review, 670.
observing, however, that, except for mere convenience, there seems no reason why subject-matter and consideration should not be treated together as one topic.5