1911 Encyclopædia Britannica/Consideration

CONSIDERATION (from Lat. considerare, to look at closely, examine, generally taken to be from con-, and the base seen in sidus, sideris, a star, the word being supposed to be originally an astrological or astronomical term), observation, attention, regard or taking into account, hence the fact taken into account, and especially something given as an equivalent or reward or in payment; in the law of contract, an act or forbearance, or the promise thereof, offered by one party to an agreement, and accepted by the other as an inducement to that other’s act or promise (Pollock on Contract). Consideration in the legal sense is essential to the validity of every contract unless it is made in writing under seal. The meaning of the word is quite accurately expressed by a phrase used in one of the earliest cases on the subject—it is strictly a quid pro quo. Something, whether it be in the nature of an act or a forbearance, must move from one of the parties in order to support a promise made by the other. A mere promise by A to give something to B cannot be enforced unless there is some consideration “moving from B.” While every contract requires a consideration, it is held that the court will not inquire into the adequacy thereof, but it must be of some value in the eye of the law. It must also be legal, and it must be either present or future, not past. See further Contract.