Equity, in a general sense, natural right, but as used in jurisprudence an administration of law with reference to the particular circumstances of a case, in contradistinction to the ordinary method of adjudicating by a rule of general application. This is a theoretical rather than a practical view, for equity as distinguished from strict law is necessarily administered by uniform rules. A judgment founded upon the particular circumstances of a case, without any reference to principles applying in common to such case and to others, would hardly deserve the name of a judicial decision, but rather would be an arbitrary opinion unregulated by legal analogy. This has never been the nature of equity as administered in any country where laws have been prescribed for the regulation of society. At an early period, it is true, many cases would occur which were not provided for by legislation. In these a discretion must be exercised; but every case when decided becomes a precedent, and thus in time the equitable or exceptional law acquires a systematic form and obligation. Another class of cases is where a positive law is productive of some individual hardship not contemplated in the enacting of the law.

Relief may then be afforded by the intervention of an equitable power, whose office is not to abrogate or interfere with the operation of the law according to its real intent, but to afford exemption in cases which were probably not foreseen, and therefore could not have been intended. Again, there may be an omission in a law, whether it be statutory or derived from custom, to provide for cases of non-compliance by reason of casualty or some cause not involving serious fault. Thus where forfeitures or penalties are consequent upon the failure of strict performance of an agreement, there is an obvious distinction between intentional neglect and accidental failure, especially if in the latter case it was by inevitable misfortune. There is here room for equitable relief in the one case without impairing the operation of the law in the other, to which alone it justly applies. It is indeed difficult to distinguish with exact precision the line that divides culpable negligence from excusable omission, or to determine how far actual disability should be a ground of relief from legal obligation. Where no fraud is involved, the obligation of contracts cannot as a general rule be abrogated by a court of equity.

Hardship will sometimes occur, and there is a natural impulse to give relief in the individual case; but such leniency often repeated is found to be productive of counterbalancing consequences not at first anticipated, and the necessity of a general rule becomes apparent. The discretionary power of the Roman praetor was at first unrestricted, but ft was early brought under certain rules from which he was not allowed to depart. It is true that annually when each praetor went into office he made a formal publication of the rules by which he would be governed in his administration of the laws during his term of office, which might allow the inference that he had an arbitrary liberty to disregard former precedents; but practically it was but the adoption of the edict of his predecessors, with occasional modifications suggested by enlarging experience. - The English equity system was early dissevered from the ordinary administration of law, and has ever since remained separate. Yet the equitable principles maintained in the court of chancery could have been applied by the common-law courts, and to some extent the latter have been compelled to admit modifications into their practice by analogy to equitable proceedings.

Thus the penalty of a bond was formerly held to be the debt, and to be recoverable; yet after the court of chancery gave relief upon the payment of the real debt, which was usually specified in the condition of the bond, the common-law courts gave the same relief at any time before judgment; though if payment of the amount really due was not prior to that time tendered, judgment could be entered for the penalty and enforced by execution for the whole amount. A similar change has also taken place with regard to mortgages. (See Mortgage.) Again, the conveyance of lands to uses became a peculiar subject of equity jurisdiction; the use not being recognized at law, but being enforced in chancery. The statute of uses (27 Henry VIII.) was intended to make the use cognizable as the real title in courts of common law, but this effect was defeated by the over-nice scruple of the judges, whereby a limitation of a second use (as when a conveyance was made to A for the use of B, in trust for C) was held not to be within the statute; and the court of chancery again intervened to enforce such second use under the name of a trust, and has ever since retained exclusive jurisdiction of that class of cases in England. Another peculiarity of the English equity system was formerly the right of calling upon the defendant in the action to testify, first by a sworn answer to the complaint, and then by examination upon accounting, and in various other cases, at the election of the complainant.

But this distinction has been superseded by the recent statutory provisions in England and most of the United States, by which parties are made competent witnesses in all the courts. (See Evidence, and also Chancery.)