CONTRACT, the term usually applied to such agreements (whether express or implied) as create, or are intended to create, a legal right, and correspond ing liability; such right not attach ing to the possession of the subject matter of the contract, except in equity, and that indirectly, but subsisting both in equity and law against the contract ing party. The conditions essential to the legal validity of a contract relate either to the competency of the parties, the sufficiency of the consideration or inducement, the nature of the thing contracted for, the fairness of the trans action, or, lastly, to the form of agree ment. First, as to the competency of the parties: The party to be sued must have been at the time of the contract of sound mind, and, unless it was for the supply of necessaries, of full age; and if a woman, she must have been unmar ried, subject as to the latter condition to some exceptions established either by local custom or by the doctrines of equity. As to the sufficiency of the con sideration on the part of the person suing: It must have been either future marriage since performed, or money, or something capable of being estimated in money; or some act, whether of per formance or abstinence, whereby some undoubted advantage, though not capa ble of being exactly valued, accrues to the party sued. The act contracted for
must be neither contrary to written law, nor to public policy; and it must be bene ficial to the party seeking either per formance or compensation, or to some one on whose behalf he gave the con sideration. There must have been neither fraud (either by concealment or misstatement) nor compulsion on the part of the plaintiff in obtaining the agreement; and fraudulent acts subse quent to the agreement having reference to it are also sufficient to deprive the guilty party of all right under it. Some circumstances are in equity considered either as conclusive evidence of fraud, or as substantive acts of coercion, which are not strictly of such a nature, and are not so deemed at law. Lastly, as to the form of the agreement: Where it relates to an interest in land of three years' duration or more, or to goods of the value of $50 or upward, unless there be earnest or delivery, or where it is an agreement as surety, or where it is upon marriage as a consideration, it must, by American law, be in writing; though the want of a written instrument may be supplied in equity by partial perform ance, that is, by acts evidently done in pursuance of the alleged contract.