In use long before the Constitution, the injunction in the twentieth century came to play one of its most important roles as the enforcer of constitutional and CIVIL RIGHTS. Precisely because it is effective, flexible, and open-ended, the injunction has drawn opposition, and constitutional cases have often included fierce battles over whether the injunction ought to be used as a remedy. These battles have resulted in some complex judicially imposed limitations on the use of injunctions in public law cases.
The injunction rests on a simple idea: that a court may order someone to perform or to cease some action. However simple the idea, it was not a usual feature of the earliest English COMMON LAW. Although it is inaccurate to say that early common law never commanded the performance of an action, by the sixteenth century its typical judgment simply decreed that A, having won the suit, was entitled to "take" some sum of money from B. If B did not cooperate, A could often gain the assistance of the sheriff, but B was subject to no direct order to do anything.
By contrast to the common law courts, the Court of
Chancery administered a system of remedies that came to be called EQUITY, vindicated by an order directing someone to do or cease doing something. At an early stage only the imagination of the Chancellor, who presided over the court, limited the precise nature of such orders. Equity has never lost this tradition of flexibility and discretion, but as Chancery developed a sense of precedent, the occasions for such orders began to seem standardized. For example, a court might require a defendant to perform a trust, to convey land, to carry out a contract, or to pay money owed to a business partner. Some orders, typically those forbidding an action (for example, requiring a party to halt a lawsuit or to cease polluting a stream), came to be called injunctions, though the term "injunctive relief" is often used broadly to refer to direct judicial orders of many sorts. Such equitable remedies always remained relatively discretionary: Chancery would not, for example, enter an injunction in all cases; the litigant seeking such an order first had to convince that court that his remedy at law (i.e., from the common law courts) would be "inadequate," a deceptively simple term that over five centuries has taken on some surprising baggage. Because of this requirement a litigant can have a valid legal right for...