Sources of law: legislation, precedent and custom

1. What “source” means

Salmond distinguishes formal sources, from which a rule gets its force and validity (the will of the State expressed through legislation or the courts), from material sources, from which it gets its content. Material sources are either legal (legislation, precedent, custom, agreement) or historical (writings of jurists, foreign law, religious texts, reports of commissions) which influence the law but do not bind a court by themselves.

In modern India the order of authority is: the Constitution, then legislation (Acts of Parliament and State Legislatures, and delegated legislation made under them), then precedent (binding decisions of the Supreme Court and the High Courts), then custom (where law allows it), and then persuasive sources such as equity, justice and good conscience.

2. Legislation

Legislation is law made deliberately by a body with authority to make it. Salmond calls it “that source of law which consists in the declaration of legal rules by a competent authority.”

• Supreme legislation comes from the sovereign legislature and cannot be repealed or controlled by any other legislative authority. In India Parliament and State Legislatures are supreme within their fields, subject to the Constitution and judicial review.
• Subordinate legislation comes from an authority other than the sovereign legislature, under power delegated by it: rules, regulations, by-laws, notifications. It is valid only within the limits of the parent Act.
• Merits. It can abrogate as well as create; it is made in advance, so people know the rule before they act; it is stated in a fixed form; it can be general and systematic (the Bharatiya Nyaya Sanhita, 2023 replacing the Indian Penal Code from 1 July 2024 is an example).
• Demerits. Fixed words cannot foresee every case, which is why courts must interpret them (Unit IV).

3. Precedent

A precedent is a judicial decision containing a principle that later courts follow. The binding part is the ratio decidendi, the principle necessary for the decision; the rest is obiter dicta, which may persuade but does not bind.

• Article 141 of the Constitution: the law declared by the Supreme Court is binding on all courts within the territory of India.
• The hierarchy of courts: a High Court’s decisions bind the courts subordinate to it, which work under its superintendence (Article 227).
• The Supreme Court is not bound by its own earlier decisions and may depart from them: Bengal Immunity Co. Ltd. v. State of Bihar, 1955 INSC 36, AIR 1955 SC 661. But a smaller bench is bound by a larger bench: Central Board of Dawoodi Bohra Community v. State of Maharashtra, 2004 INSC 720, (2005) 2 SCC 673.
• Judges as law-makers. Where there is a gap, the Supreme Court has laid down rules that operate as law until the legislature acts. In Vishaka v. State of Rajasthan, 1997 INSC 604, (1997) 6 SCC 241, it framed guidelines against sexual harassment at the workplace, which governed until the Sexual Harassment of Women at Workplace Act, 2013.

4. Legislation and precedent compared

The two work together. Statutes leave gaps and ambiguities; precedent fills and settles them; when precedent goes wrong, the legislature corrects it. That cycle is the normal way Indian law develops.

5. Custom

A custom is a rule of conduct followed so long and so uniformly in a place, community or family that it has acquired the force of law. Section 3(a) of the Hindu Marriage Act, 1955 defines “custom” as a rule which, having been continuously and uniformly observed for a long time, has obtained the force of law among Hindus in any local area, tribe, community, group or family.

Essentials of a valid custom (the January 2026 short note):

1. Antiquity. It must be ancient. English law fixed 1189 (the start of Richard I’s reign) as the limit of legal memory; Indian courts require long usage without a fixed date.
2. Continuity. It must have been followed without interruption.
3. Peaceable enjoyment. It must have been followed without dispute or force.
4. Certainty. Its content must be clear and definite.
5. Reasonableness. It must not be unreasonable or contrary to justice.
6. Obligatory force. People must follow it because they believe they are bound (opinio necessitatis), not by mere convenience.
7. Conformity with statute and public policy. A custom cannot override an Act, and must not be immoral or opposed to public policy.
8. Consistency with the Constitution. Customs and usages are “law” under Article 13(3)(a) and are void if they violate fundamental rights.

6. How custom is transformed into law

Two theories answer the June 2025 and January 2026 question.

• Historical school (Savigny, Puchta). Custom is law in itself because it expresses the common consciousness of the people. No act of the State is needed.
• Analytical school (Austin). Custom is only a source of law, a “positive morality”, until the sovereign or its courts adopt it. A custom becomes law when a court recognises and enforces it, or the legislature enacts it.

Indian practice follows the analytical line. A custom becomes law by one of three routes:

1. Judicial recognition. A party who sets up a custom must plead and prove it; once a court finds it proved and valid, the decision becomes evidence of the custom for later cases.
2. Legislative adoption. Statutes preserve customs expressly: the Hindu Marriage Act, 1955 lets custom permit marriage within prohibited degrees (section 5(iv)) and customary forms of divorce (section 29(2)).
3. Codification and replacement. The legislature may write a custom into a code, or abolish it, as the Child Marriage Restraint Act, 1929 and later the Prohibition of Child Marriage Act, 2006 did for child marriage.

Custom can also lose its legal force. In Shayara Bano v. Union of India, 2017 INSC 785, (2017) 9 SCC 1, the Supreme Court set aside the practice of instantaneous triple talaq. Parliament then made it a punishable offence in 2019.

7. Other sources

• Equity, justice and good conscience — applied by Indian courts where no rule exists.
• Juristic writings — persuasive (Salmond, Mulla, Seervai).
• Conventions — constitutional practices, not enforced by courts.
• Agreement — contracts and treaties create rules for the parties.

How this is examined

For “sources of law”, give the formal and material classification, then each source with an Indian illustration and a closing comparison. For “legislation and precedent”, use the table in section 4. The custom notes need the eight essentials, or the two theories and three Indian routes, with section 3(a) of the Hindu Marriage Act as the definition.