Case law techniques: reading a judgment, ratio decidendi and obiter dicta

1. Reading a judgment

A reported judgment has a predictable shape. Learning to find each part quickly is the first case-law skill.

1. Title and citation — parties, court, date, neutral citation and report citation.
2. Bench — the judges, and their number (a Constitution Bench has five or more).
3. Headnote — the reporter’s summary. Useful for finding cases, but it is not part of the judgment and may be wrong.
4. Facts — what happened and how the case came to this court.
5. Issues — the questions of law and fact the court must answer.
6. Arguments — of each side, with the authorities cited.
7. Reasoning — the court’s analysis of the law and its application to the facts. The ratio is found here.
8. Decision (order) — appeal allowed or dismissed, relief granted.
9. Separate opinions — concurring or dissenting judgments. The ratio is that of the majority.

Briefing a case. Students should reduce every important case to a half-page brief under the heads: citation, facts, issue, held, reasoning (ratio), obiter, comment. This is also the right form for a short note on a case in the examination.

2. Ratio decidendi

The ratio decidendi (“reason for deciding”) is the principle of law on which the decision is based, read with the material facts. Salmond calls it the authoritative element of a precedent. It is binding on lower courts; it is what Article 141 means by “law declared”.

The judge does not label the ratio. It must be extracted by the later reader. Hence the June 2025 and February 2025 questions on methods of extraction.

3. Methods of extracting the ratio

• Wambaugh’s reversal test. Frame the proposition you think is the ratio, then insert its opposite. If, with the opposite proposition, the court would have reached a different decision, the proposition is the ratio; if the decision would have been the same, it is not. Weakness: it fails where the court gives two independent reasons, each sufficient.
• Goodhart’s material facts test. Identify the facts the judge treated as material, and the decision on them. The ratio is the decision as based on those material facts. A later case with the same material facts must reach the same result unless there is an additional material fact. Facts of person, time, place, kind and amount are usually not material unless the judge says they are.
• The court’s own statement. Indian courts often state the principle in terms (“we hold that ...”). This is strong evidence of the ratio but must still be read with the facts.
• Reading later cases. The ratio of a case is often fixed by how later courts treat it: they may confine it narrowly to its facts or state it broadly.
• Multiple judgments. Where judges agree on the result for different reasons, the ratio is the reasoning common to the majority; if there is none, the case binds only on the same facts.

4. Worked example: Donoghue v. Stevenson [1932] AC 562

Facts. A friend bought Mrs. Donoghue a bottle of ginger beer in a café in Paisley, Scotland. The bottle was opaque. After drinking some she poured the rest and, she alleged, found the decomposed remains of a snail. She suffered shock and gastro-enteritis. She had no contract with the manufacturer, Stevenson. The House of Lords held, by three to two, that she had a cause of action in negligence.

The ratio at different levels of generality. The case is the standard illustration of how a ratio may be stated narrowly or widely:

1. Narrowest: a manufacturer of ginger beer in opaque bottles owes a duty to the consumer.
2. Middle (the accepted ratio): a manufacturer of products sold in a form which shows that he intends them to reach the ultimate consumer without reasonable possibility of intermediate examination owes that consumer a duty to take reasonable care.
3. Widest: Lord Atkin’s “neighbour principle” — you must take reasonable care to avoid acts or omissions which you can reasonably foresee would be likely to injure your neighbour, meaning persons so closely and directly affected that you ought to have them in contemplation.

The neighbour principle was at first treated as wider than necessary for the decision, close to obiter. Later courts adopted it as the general basis of the duty of care. This shows how the ratio is fixed by later use.

5. Obiter dicta

An obiter dictum (“a thing said by the way”) is a statement of law not necessary for the decision: a hypothetical, a view on a point not argued, or a wider proposition than the facts require. It does not bind, but it may be highly persuasive depending on the court and the care with which it was said. Obiter of the Supreme Court is treated with great respect by High Courts and is ordinarily followed. A dissenting judgment is also persuasive only.

6. Inductive and deductive reasoning

• Inductive reasoning moves from particular decisions to a general principle. The common law grows this way: from several cases on manufacturers, a court induces the general duty of care. Extracting a ratio from a line of cases is inductive.
• Deductive reasoning moves from a general rule to a particular case, in the form of a syllogism: the rule (major premise), the facts (minor premise), the conclusion. Applying a statute is mainly deductive.
• Reasoning by analogy combines them: is the new case like the precedent in its material facts? If yes, follow it; if a material fact differs, distinguish it.

7. Circumstances affecting the binding force of a precedent

1. Overruling by a higher court or a larger bench of the same court.
2. Reversal of the very decision on appeal.
3. Statutory abrogation — the legislature changes the law on which the case rests.
4. Per incuriam — a decision given in ignorance of a statute or a binding precedent.
5. Sub silentio — a point that was not argued or considered.
6. Inconsistency between decisions of co-equal benches; the larger bench prevails, as held in Central Board of Dawoodi Bohra Community v. State of Maharashtra, 2004 INSC 720, (2005) 2 SCC 673.
7. Bench strength — a decision of a larger bench binds a smaller one: Union of India v. Raghubir Singh, 1989 INSC 192, (1989) 2 SCC 754.
8. The Supreme Court and its own decisions — it may depart from them: Bengal Immunity Co. Ltd. v. State of Bihar, 1955 INSC 36.
9. Prospective overruling — in I.C. Golak Nath v. State of Punjab, 1967 INSC 45, AIR 1967 SC 1643, the Court declared that its ruling would operate only for the future, leaving past amendments valid.
10. Factors adding weight — unanimity, the eminence of the judges, age and approval in later cases; factors reducing weight — a strong dissent, a divided court, or obvious error.

How this is examined

The ratio question is the commonest Unit IV essay: define it, explain why it must be extracted, give Wambaugh and Goodhart, and illustrate with Donoghue. “Obiter dictum” is a 6-mark note: definition, kinds, persuasive value, Supreme Court obiter. The binding-force question needs the numbered list with the four Indian cases.