This essay summarizes, analyzes and critiques legal and equitable principles in their historical context and then examines in commercial contexts three doctrines of equity jurisprudence, unconscionability, promissory estoppel and quasi-contract/unjust enrichment and a specific dispute resolution technique of growing importance which incorporates equitable principles, arbitration. The overall conclusion reached is that the dynamic tension between legal and equitable concepts contributes to the vitality of the American legal process and its fairness for participants in commercial transactions.
Definitions. Law is a system of constraints on the behavior of individuals and groups in society which is sanctioned and enforced by the state. Justice might be defined as that system of law which satisfies most people's sense of fairness. Black's Law Dictionary uses in part a definition of law which is close to the above: "that which must be obeyed and followed by citizens, subject to sanctions or legal consequences" and "the constant and perpetual disposition to render every man his due" (at 1028 and 1002, 4th ed. (1951)). It can be readily be seen from these definitions that it is much easier to define the law than justice. Legal realists like the late Supreme Court Justice Oliver Wendell Holmes have said that the law is simply what the courts say it is, but his formulation begs the question of what it ought to be. Most legal scholars agree that the law reflects the moral values of society, but not everyone at any given time will agree on what those moral values are or should be. Nevertheless, over time, a consensus has developed in western civilization that the rigors of the law need to be leavened or eased by more general concepts of fairness or natural justice.
Classical notions of equity. Aristotle's concept of equity or epieikeia was that "though just, [it] is not legal justice, but a rectification of legal justice" . . . "equity i...