Substantive vs Adjective Law: Law of Evidence Explained

Substantive Law and Adjective Law: The Place of the Law of Evidence

The Foundational Distinction

Every developed legal system rests on two great pillars. The first creates rights and duties — it tells us what the law is. The second provides the machinery for enforcing those rights — it tells us how the law operates in a court of justice. These two pillars are what jurists call Substantive Law and Adjective Law (also known as procedural or adjectival law).

Substantive law defines the substantive rights and liabilities of parties. The Transfer of Property Act, the Indian Penal Code, the Hindu Succession Act — all of these belong to this category. They lay down the rule that if certain conditions are satisfied, one person has a right and another bears a corresponding liability. The advocate who advises a client begins precisely here: she looks up the substantive rule, checks whether the conditions for its application are met, and then advises accordingly.

Adjective law, by contrast, governs the process by which those substantive rights are vindicated before a court. It covers the mode of pleading, the procedure of trial, and — crucially — the rules of evidence. It does not create any independent right of its own; it is, in the words of a great jurist, the handmaid of substantive law, providing the instruments by which truth is established in judicial proceedings.

To illustrate with a simple example: the Indian Contract Act (substantive) tells us that a valid contract creates an enforceable obligation. But when A sues B for breach of contract, the rules that determine what A must prove, what documents he may produce, what questions he may ask B in cross-examination — all of that belongs to adjective law. The substantive rule gives the right; the adjective rule gives the remedy its wings.

The Law of Evidence as Adjective Law

The law of evidence is adjective law — and this classification is not merely academic. It has a profound bearing on how the courts understand its purpose. Evidence law does not declare who has a right or who bears a liability; it instead determines how facts are to be proved before a court so that the substantive rights declared by the law can be judicially enforced.

The Indian Evidence Act, 1872 — and its successor, the Bharatiya Sakshya Adhiniyam, 2023 (BSA) — both serve this adjective function. Section 5 of the Evidence Act (corresponding to Section 4 of the BSA) expressly confines the court's attention to evidence of facts in issue or relevant facts, thereby channelling the entire fact-finding process towards the adjudication of substantive rights. The Act does not tell A whether he owns the property; it tells the court what evidence may be received to determine whether he does.

The classification of evidence law as adjective law also explains one of its most important characteristics — it applies generally to civil and criminal proceedings alike, regardless of the substantive domain of the case. Whether the dispute concerns a breach of contract or a murder charge, the same statute — the Evidence Act — governs the rules of proof. The substantive law changes; the adjective framework remains constant.

The General Principle: Evidence Rules Apply Equally in Civil and Criminal Proceedings

Section 1 of the Indian Evidence Act, 1872 makes clear that the Act applies "to all judicial proceedings in or before any court." The general principle, long accepted in jurisprudence, is that the rules of evidence are the same whether the proceeding is civil or criminal. The rules of relevancy under Sections 6 to 55, the provisions governing admissions, documentary evidence, examination of witnesses, and the burden of proof are all common to both kinds of proceedings.

That said, the legislature has carved out important exceptions to this general principle, responsive to the distinct needs of civil and criminal justice.

Three Important Exceptions

First Exception: Confession to a Police Officer (Section 25 / Section 22 BSA)

In civil proceedings, an admission made by a party is freely receivable in evidence against that party. But in criminal proceedings, no confession made to a police officer shall be proved as against a person accused of any offence — this is the categorical mandate of Section 25 of the Evidence Act (Section 22 of BSA). This provision has no counterpart in civil law. Its purpose is protective: the historical reality of police coercion and the third-degree methods employed to extract confessions compelled the legislature to create an absolute bar. As the Allahabad High Court observed in Queen-Empress v. Balmukund (1885 ILR 7 All 509), the legislature was acutely aware of the malpractices of police officers in extorting confessions from accused persons, and the rule was designed to take away from the police the advantage of proving such extorted confessions at trial. This rule operates solely in the criminal domain; in a civil suit, no such bar exists against proving admissions made to any person, including a police officer.

Second Exception: Burden of Proof and Standard of Proof

In civil proceedings, the general rule is that the burden of proof lies on the person who asserts the affirmative of an issue, and the standard is proof on a preponderance of probabilities. In criminal proceedings, the prosecution must prove the guilt of the accused beyond reasonable doubt — a significantly higher standard. The accused, by contrast, need only raise a reasonable doubt in the mind of the court. Section 101 of the Evidence Act (Section 97 of BSA) lays down the general principle; but in criminal cases, Sections 101 to 105 (Sections 97 to 101 of BSA) operate in a fundamentally different manner, reflecting the constitutional imperative of the presumption of innocence. The Supreme Court articulated this distinction with characteristic clarity in Woolmington v. Director of Public Prosecutions (1935 AC 462, followed consistently in India) — the golden thread running through English criminal law, fully absorbed into Indian jurisprudence, is that it is for the prosecution to prove the prisoner's guilt.

Third Exception: Competency and Compellability of the Accused

In civil proceedings, under Section 120 of the Evidence Act (Section 115 of BSA), parties to the suit — including the plaintiff and defendant — are competent witnesses and may be called to testify. There is no general privilege against self-incrimination that prevents a civil defendant from being examined. But in criminal proceedings, the accused occupies a dramatically different position. By virtue of Article 20(3) of the Constitution — which provides that no person accused of any offence shall be compelled to be a witness against himself — and Section 315 of the Code of Criminal Procedure, 1973 (Section 351 of BNSS, 2023), the accused cannot be summoned as a prosecution witness. He may appear as a defence witness only on his own written request. Even when he does so, he cannot be compelled during cross-examination to answer questions that tend to criminate him. This privilege against testimonial compulsion exists only in the criminal sphere; in civil proceedings, the opposing party may compel the other side to appear and answer.

The Legislative Policy Behind Sections 123 and 162 of the Indian Evidence Act

Section 123 — Evidence as to Affairs of State

Section 123 provides that no one shall be permitted to give any evidence derived from unpublished official records relating to any affairs of State, except with the permission of the officer at the head of the department concerned, who shall give or withhold such permission as he thinks fit. The corresponding provision in the Bharatiya Sakshya Adhiniyam, 2023 is Section 129 of BSA, which substantially re-enacts this rule.

The legislative policy behind this provision rests on a fundamental tension between two compelling public interests. The first is the principle of transparency — that in a democratic polity, public affairs ought to be known to the people who are governed by them. The second is the imperative of national security and public interest — that certain categories of sensitive state information, if disclosed in open court, could cause grave harm to the governance of the nation. The traditional maxim is salus populi suprema lex — the good of the people is the highest law. The section is thus grounded not in executive convenience, but in the protection of genuine public interest.

The section deploys several important ingredients. The words "no one shall be permitted" indicate that the bar operates against everybody — not merely those in official custody of the document, but any person who might have come to possess the information. The privilege therefore attaches to the information itself, not to any particular official. The word "unpublished" does not merely mean physically not printed; it connotes a deliberate state intention to keep the records away from public knowledge because they relate to the affairs of State — in other words, unpublicised. The phrase "affairs of State" has been interpreted to mean State secrets, State papers, and communications between the Government and its officials with regard to matters whose disclosure would be prejudicial to public interest — such as national defence, sensitive diplomatic relations, or matters of intelligence.

The section also requires the permission of "the officer at the head of the department concerned," who has discretion to grant or withhold that permission. The phrase "as he thinks fit" initially gave rise to the question whether the executive certificate was conclusive and immune from judicial scrutiny. In State of Punjab v. Sodhi Sukhdev Singh (AIR 1961 SC 493), the Supreme Court took the position that the executive certificate was binding on the court, and that the Court should not inspect the document. However, the law underwent a decisive transformation in S.P. Gupta v. President of India (AIR 1982 SC 149), where a Constitution Bench of the Supreme Court, speaking through P.N. Bhagwati, J., held that the courts retain the residual power to balance the injury to the State or public interest against the risk of injustice, and that the Court may inspect the document if it is in doubt — though this power must be exercised sparingly.

Section 162 — Procedure for Production of Documents

Section 162 of the Evidence Act (Section 168 of BSA) is the procedural counterpart to Section 123. It lays down that a witness summoned to produce a document shall, notwithstanding any objection to its production or admissibility, bring it to court. The section then vests in the court the power to inspect the document — unless it refers to matters of State — or to take other evidence to determine its admissibility. The court may also, if necessary, direct the translator to keep the contents secret.

The legislative policy behind Section 162 is to ensure that documents do not silently disappear from judicial proceedings simply because an official objects to their production. The production of the document before the court and its admission as evidence are two distinct steps. The official must bring the document; the court decides whether it goes on record. If the document refers to matters of State, the court may not inspect it but may receive other evidence to decide the question of admissibility. This is the safeguard against judicial overreach in sensitive executive matters.

The interplay between the two sections was clearly articulated in Ramanna v. State of Andhra Pradesh (AIR 1968 SC 196), where the Supreme Court held that there is an absolute prohibition on the court's inspection of a document that pertains to matters of State. The court may, however, examine other evidence — typically an affidavit from the minister or head of department — to determine whether the claim of privilege is genuine.

In S.P. Gupta (supra), Bhagwati, J., carved out a further nuance: if there is any doubt whether the document truly relates to affairs of State, the court may, in an appropriate case, inspect it to satisfy itself whether disclosure would be injurious to public interest. This power, he cautioned, must be exercised sparingly and only when the court has genuine reason to doubt the claim. The Law Commission of India, in its 185th Report, endorsed this balanced approach, acknowledging that to leave the determination of injury to public interest entirely to the discretion of a public servant is unsatisfactory, and that the final say must rest with the courts.

The distinction between Sections 123 and 162 is thus architecturally clear: Section 123 defines the substantive privilege, while Section 162 prescribes the procedural mechanism for testing and enforcing it. Together, they reflect the legislature's attempt to reconcile the competing imperatives of executive confidentiality and judicial accountability — an enduring tension that the courts have navigated with increasing sophistication in a constitutional democracy committed to the rule of law.