What, then, is the true nature of the distinction? The law of procedure may be defined as that branch of the law which governs the process of litigation. It is the law of actions—jus quod ad actiones pertinet—using the term action in a wide sense to include all legal proceedings, civil or criminal. All the residue is substantive law, and relates not to the process of litigation, but to its purposes and subject-matter. Substantive law is concerned with the ends which the administration of justice seeks; procedural law deals with the means and instruments by which those ends are to be attained. The latter regulates the conduct and relations of courts and litigants in respect of the litigation itself; the former determines their conduct and relations in respect of the matters litigated. Procedural law is concerned with affairs inside the courts of justice; substantive law deals with matters in the world outside.
A glance at the actual contents of the law of procedure will enable us to judge of the accuracy of this explanation. Whether I have a right to recover certain property is a question of substantive law, for the determination and the protection of such rights are among the ends of the administration of justice; but in what courts and within what time I must institute proceedings are questions of procedural law, for they relate merely to the modes in which the courts fulfil their functions. What facts constitute a wrong is determined by the substantive law; what facts constitute proof of a wrong is a question of procedure. For the first relates to the subject-matter of litigation, the second to the process merely. Whether an offence is punishable by fine or by imprisonment is a question of substantive law, for the existence and measure of criminal liability are matters pertaining to the end and purpose of the administration of justice. But whether an offence is punishable summarily or only on indictment is a question of procedure. Finally it may be observed that, whereas the abolition of capital punishment would be an alteration of the substantive law, the abolition of imprisonment for debt was merely an alteration in the law of procedure. For punishment is one of the ends of the administration of justice, while imprisonment for debt was merely an instrument for enforcing payment.
So far as the administration of justice is concerned with the application of remedies to violated rights, we may say that the substantive law defines the remedy and the right, while the law of procedure defines the modes and conditions of the application of the one to the other.
Although the distinction between substantive law and procedure is sharply drawn in theory, there are many rules of procedure which in their practical operation are wholly or substantially equivalent to rules of substantive law. In such cases the difference between these two branches of the law is one of form rather than of substance. A rule belonging to one department may by a change of form pass over into the other without materially affecting the practical issue. In legal history such transitions are frequent, and in legal theory they are not without interest and importance.
Of these equivalent procedural and substantive principles there are at least three classes sufficiently important to call for notice here.
1. An exclusive evidential fact is practically equivalent to a constituent element in the title of the right to be proved. The rule of evidence that a contract can be proved only by a writing corresponds to a rule of substantive law that a contract is void unless reduced to writing. In the former case the writing is the exclusive evidence of title; in the latter case it is part of the title itself. In the former case the right exists but is imperfect, failing in its remedy through defect of proof. In the latter case it fails to come into existence at all. But for most purposes this distinction is one of form rather than of substance.
2. A conclusive evidential fact is equivalent to, and tends to take the place of, the fact proved by it. All conclusive presumptions pertain in form to procedure, but in effect to the substantive law. That a child under the age of seven years is incapable of criminal intention is a rule of evidence, but differs only in form from the substantive rule that no child under that age is punishable for a crime. That the acts of a servant done about his master’s business are done with his master’s authority is a conclusive presumption of law, and pertains to procedure; but it is the forerunner and equivalent of our modern substantive law of employer’s liability. A bond (that is to say, an admission of indebtedness under seal) was originally operative as being conclusive proof of the existence of the debt so acknowledged; but it is now itself creative of a debt; for it has passed from the domain of procedure into that of substantive law.
3. The limitation of actions is the procedural equivalent of the prescription of rights. The former is the operation of time in severing the bond between right and remedy; the latter is the operation of time in destroying the right. The former leaves an imperfect right subsisting; the latter leaves no right at all. But save in this respect their practical effect is the same, although their form is different.
The normal elements of judicial procedure are five in number, namely Summons, Pleading, Proof, Judgment, and Execution. The object of the first is to secure for all parties interested an opportunity of presenting themselves before the court and making their case heard. Pleading formulates for the use of the court and of the parties those questions of fact or law which are in issue. Proof is the process by which the parties supply the court with the data necessary for the decision of those questions. Judgment is this decision itself, while execution, the last step in the proceeding, is the use of physical force in the maintenance of the judgment, when voluntary submission is withheld. Of these five elements of judicial procedure one only, namely proof, is of sufficient theoretical interest to repay such abstract consideration as is here in place. The residue of this chapter, therefore, will be devoted to an analysis of the essential nature of the law of evidence.