internal aids to interpretation

Internal aids are found within the four corners of the Act. They include the long title, the preamble, headings of chapters and sections, marginal notes, definition clauses, provisos, explanations, illustrations, schedules and, to a limited extent, punctuation. Each has a different weight: illustrations are part of the Act and help explain the section, though they cannot cut down its clear words; a proviso normally carves out an exception from the main provision; a preamble and headings help resolve ambiguity but cannot control plain language.

They contrast with external aids, which come from outside the statute, such as parliamentary debates, committee reports, statements of objects and reasons, dictionaries and earlier statutes in pari materia. Students should remember the order: first the text and its internal aids, and external aids only where ambiguity remains.

Example

Relying on the illustrations to s.116 BNS as internal aids to interpretation, the court read the “fifteen days” clause as requiring actual severe pain for that period.

See also

external aids to interpretation · preamble · proviso · harmonious construction

Read more in the study notes

• Constitutional interpretation (Constitutional Law II)
• Meaning of statute and purpose of interpretation (Interpretation of Statutes and Principles of Legislation)
• Internal aids: title, preamble, headings, marginal notes, definitions and punctuation (Interpretation of Statutes and Principles of Legislation)
• Provisos, exceptions, explanations, illustrations, saving and non-obstante clauses, schedules (Interpretation of Statutes and Principles of Legislation)
• Interpretation of statutes: an introduction to the rules, context and fringe meaning (Legal Methods)