External aid of interpretation (Historical Background, Legislative History, Administrative Conveyancing, and Commercial Practice)5 min read


External aids of interpretation

While interpreting provisions of a statute, judicial institutions may use internal and/or external aids. Some of the external aids, those which assist the construction or interpretation from outside the statute are discussed below:

  • Historical background

The historical setting of a statute is of much significance to construe its comprehensive meaning. The historical facts and circumstances at the time of enactment of the statute assist in understanding the subject matter as well as the scope of the statute. It may include history in general or some contemporary writings of that time, and basically every historical fact that is helpful to arrive at the legislation’s intent and elucidate its object.

Case laws

The rule of admissibility of this external aid is especially when the mischief rule is being applied. The rule that was laid down in Heydon’s Case. In the Indian scenario, the apex court validated the aid of historical background to interpret statutes in D.K. Trivedi And Sons vs State of Gujarat(1986) “To take into account legislative history and practice when considering the validity of a statutory provision or while interpreting a legislative entry is a well-established principle of construction of statutes.”

Though in CIT vs Shodra Devi (1957)it was made clear that the historical background must give way to clear language to the statute and should be used when the language of the statute is ambiguous.

  • Legislative or Parliamentary history

This encompasses all the documents relating to the events that occurred during the conception, preparation, and passage of the said enactment. Parliamentary history may include, according to Peter Hogg, report of a royal commission or law reform commission or parliamentary committee, government policy paper (whether called a white paper, green paper, budget paper), earlier versions of the statute, either before or after its introduction into Parliament or the Legislature, speeches in the Parliament or Legislature when the bill is being debated. However, the speeches in Parliament on a statute made subsequent to its enactment — such as parliamentary statements during the debate on an unsuccessful amendment to the statute are generally not considered a part of its legislative history as such speeches did not occur during the enactment.

Parliament history is different from a historical background as the former relates to the specific details related to the legislation which may include opinions as well while the latter is mostly about facts and the social understanding of the time.

 In Harsharan Verma v. Tribhuvan Narain Singh, the appointment of Tribhuvan Narayan Singh as the then chief minister of Uttar Pradesh was challenged because, at the time of his appointment, he was neither a member of the Legislative council nor a member of the state Legislative Assembly. While interpreting Article 164(4) of the Constitution, the Supreme Court held that it did not require that a Minister should be an MLA (Member of the Legislature) at the time of his being chosen as such, the Supreme Court referred to an amendment which was rejected by the Constituent Assembly requiring that a Minister at the time of his being chosen should be a member of the Legislature.

In Mohan Lal Tripathi vs District Magistrate, Raebareli (1992), it was held that pertaining to Maxwell’s interpretations, the historical development of legislation could be used efficiently as an external aid of interpretation although a clear and unambiguous proviso cannot be interpreted by taking an analogy from earlier provision as it stood in the past and has been since amended. In Indira Sawhney v. Union of India, a landmark case remembered for interpreting Article 16(4) of the Constitution the Supreme Court referred to Dr. Ambedkar’s speech in the Constituent Assembly as the expression backward class of citizens has not been defined in the statute. The court held that reference to Parliamentary debate is permissible to an extent to ascertain the context, background, and main objective of the legislatures but at the same time such references could not be taken as conclusive or having authoritarian binding on the courts.

  • Administrative conveyancing

The uniform opinion and practice of eminent conveyancers have always had great regard paid to it by all courts of justice. The practice of conveyancers and of the legal profession was treated as having full testamentary disposition but administration conveyancers have not had always the same validation as other external aids of statute interpretation. The Court of Appeal in, London County Council v Central Land Board1 criticized the previous judgment for allowing counsel to read practice notes provided by the respondent for the guidance of its staff in the administration of the Town and Country Planning Act 1947. Official statements by the government department administering an Act, or by any other official authority concerned with the Act, may be taken into account as persuasive authority on the meaning of its provisions.

  • Commercial practice

Commercial usage has been allowed as an external aid to construction though mostly in cases related to taxations. The commercial practice also includes the social, technological, and customs that guide trade and commerce. R Lord Denning in United Dominions Trust, Ltd. v Kirkwood said “In such a matter as this, when Parliament has given no guidance, we cannot do better than look at the reputation of the concern amongst men of commerce”.


The language of law mostly gives expression to its source or origin. More often than not, the language may have a puzzling effect for example when it is found that the language of a statute is not clear. In such cases, it might not be possible to assign the dictionary meaning to certain words used in legislation. So long as the expansion of meaning takes place uniformly, the law will develop in a steady and robust manner. But if one judge takes a narrow view and the other a broader view, the law will mean different things for different persons, diluting its authority, and soon there will be confusion. To avert any such conundrum there are various aids to the rule of interpretation and in case the ambiguity is not removed even after applying the internal aids, then the external aids come in handy. They provide various methods with the help of which a statute can be interpreted and used by the judiciary in deciding cases which further help in constructing the intent of the legislation.

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