Legal Definitions - in pari materia

In pari materia is a Latin legal term meaning "on the same subject" or "relating to the same matter." It refers to a principle of legal interpretation where different laws, statutes, or legal provisions that deal with the same topic or subject should be read and understood together. Courts often apply this principle to gain a complete understanding of the lawmakers' intent, to resolve any ambiguities, or to ensure consistency across related legal texts.

Here are some examples illustrating this concept:

• Example 1: State Environmental Laws

  Imagine a state has two separate laws: the "State Clean Water Act" and the "State Hazardous Waste Disposal Act." Both laws aim to protect the environment from pollution. If a court needs to interpret a vague term like "toxic substance" within the Clean Water Act, and that act's definition is not entirely clear, the court might look to the Hazardous Waste Disposal Act. Since both laws address environmental protection and the handling of harmful materials, they are considered in pari materia. The more detailed definition of "toxic substance" found in the Hazardous Waste Disposal Act could then be used to clarify the meaning in the Clean Water Act, ensuring a consistent and comprehensive approach to environmental regulation across the state.

• Example 2: City Ordinances for Public Safety

  Consider a city that has a "Public Nuisance Ordinance" prohibiting activities that disturb the peace, and a separate "Noise Control Ordinance" that sets specific decibel limits for various times of day. If a resident complains about loud music from a neighbor, and the Public Nuisance Ordinance broadly refers to "unreasonable disturbances," a judge might consult the Noise Control Ordinance. Since both ordinances address public disturbances and noise, they would be read in pari materia. The specific decibel limits and time restrictions in the Noise Control Ordinance would help the judge determine what constitutes an "unreasonable disturbance" under the Public Nuisance Ordinance, providing clear standards for public safety.

• Example 3: Federal Tax Codes

  The federal tax system is vast, with many different sections and acts. Suppose there's a provision in the "Internal Revenue Code" that offers a tax credit for "energy-efficient home improvements," and a separate, more recent "Energy Policy Act" defines specific types of materials and installations that qualify as "energy-efficient" for other federal programs. When a taxpayer claims the credit under the Internal Revenue Code, and there's ambiguity about what qualifies, the tax court might interpret the Internal Revenue Code provision in pari materia with the Energy Policy Act. By considering both laws, which deal with promoting energy efficiency, the court can arrive at a consistent understanding of what improvements are eligible for the tax credit, reflecting a broader governmental policy.