Say the ratio out loud before you open Reasoning — recalling it unprompted is exactly what the exam pays for.
Why it matters
Section 91 is the best-evidence rule in its documentary form: where the terms of a contract, grant or other disposition of property, or any matter required by law to be reduced to the form of a document, have been reduced to writing, the contents of that writing must be proved by the writing itself. It forbids proof of the contents of a writing otherwise than by the writing. It binds even a stranger to the document: a third party seeking to prove a written contract can prove it only by producing the writing.
The rule is therefore powerful, and students over-apply it — treating every written instrument as the exclusive proof of the transaction it records. Taburi Sahai fixes the boundary.
Facts
The dispute concerned the adoption of a child, which had been recorded in a deed of adoption. The question was whether the fact of adoption could be proved only by producing that deed, or whether it could be established by other evidence.
Held
The Supreme Court held that a deed of the adoption of a child is not a contract within the meaning of s. 91, and therefore the fact of adoption can be proved by any evidence apart from the deed. The same is true of a will.
Reasoning
Step one — s. 91 bites on categories, not on documents. The section applies to the terms of a contract, grant or other disposition of property, and to any matter required by law to be reduced to the form of a document. A writing that records an event which falls in none of those categories is simply a piece of documentary evidence, not the exclusive repository of the transaction.
Step two — adoption is such an event. Adoption is a status created by act of the parties; the deed evidences it. Since no law required the adoption to be reduced to writing, and the deed is not a contract, the fact may be proved by any admissible evidence.
Step three — the principle of exclusion is confined to terms. Where a matter merely happens to be mentioned in a contract but is not one of its terms, that matter can be proved by evidence other than the document.
Step four — where both kinds of evidence are admissible, neither automatically wins. Where oral as well as documentary evidence are admissible on their own merits and have both been admitted, the court may go by whichever seems the more reliable. There is nothing in the statute requiring documentary evidence to prevail over oral evidence.
Exam use
Taburi Sahai is the case to cite whenever a problem turns on whether a written instrument shuts out other proof. Ask three questions in order: is the writing a contract, grant or disposition of property; if not, is this a matter which some law required to be in writing; and if neither, is the fact sought to be proved a term of the document at all? A negative at any stage takes the case outside s. 94 (IEA s. 91).
Distinguish two neighbouring rules that examiners like to fold into the same question. First, BSA s. 95 (IEA s. 92) excludes oral evidence to contradict, vary, add to or subtract from the terms of a document once those terms have been proved under the preceding section — it operates only between the parties and their representatives in interest, and only after s. 94 has been satisfied. Second, where a document is inadmissible for want of registration or insufficiency of stamp, secondary evidence of its contents — an oral account or a photocopy — is not allowed in either, and a witness may not be confronted with such a copy.
It does not decide anything about the weight of the adoption evidence, and it does not relax the rule for documents that genuinely record contracts or dispositions.