First named (in Article III) among the subjects to which the judicial power "shall extend" are "all Cases, in Law and Equity, arising under this Constitution, the Laws of the United States, and Treaties made, or which shall be made, under their authority." The word "equity" has here a technical meaning well comprehended by American lawyers of the eighteenth century, and today still generally familiar to lawyers in all legal systems derived from that of England. The explanation is necessarily historical.
In a development more than well begun in the Middle Ages, and pretty much completed by Stuart times, England developed a unique double system of courts at the national level?the courts of "law," or COMMON LAW courts, and the "court of equity"?or, as it was often called, the "court of chancery."
The common law courts administered a system of law that was radically deficient, first as to remedies available, and, second, as to the breadth of considerations that could be taken into account in the formation of decisions. These courts could in most cases award only damages in money, in many cases a step inadequate to the doing of full justice. The common law courts were also excessively formalistic. If, for example, an error occurred in the transcription of a written contract, the common law courts had no conceptual apparatus for dealing with the mistake. Similarly, they had little capacity for taking into account the problems created by fraud. And the "trust," an institution of great importance, was utterly unknown to the "common law."
During the Middle Ages, suitors who could not get full justice out of the common law courts began to appeal to the Lord Chancellor, a high royal official, for supplementary or corrective help. By Tudor times, this practice had become firmly institutionalized, so that the Lord Chancellor became in some sense a judicial officer, hearing and dealing with such pleas. Little by little, the "chancery" came to be a court. This court had at its disposal a remedy enormously more versatile and efficient than the award of damages?the remedy of the order, or command, that the defendant do or refrain from doing something. The chancery court, in contrast to the courts of common law, knew nothing of the jury; the Chancellor decided all issues of fact and law.
This "court of chancery" opened its eyes, moreover, to many things the common law courts were institutionally
disabled from seeing...