Legal Definitions - lex posterior derogat priori

Lex posterior derogat priori is a legal principle meaning that a later law prevails over an earlier one. This principle applies when a newer statute or regulation either explicitly cancels an older one or is so clearly inconsistent with it that both cannot be enforced simultaneously. In such cases, the more recent law is considered the current and binding rule.

Here are some examples to illustrate this principle:

• Environmental Regulations: Imagine a state passed a law in 1995 that allowed factories to discharge a certain level of a specific pollutant into local rivers. In 2020, the state legislature passes a new, comprehensive environmental protection act. This new act significantly lowers the permissible levels of that same pollutant and includes a clause stating that all prior conflicting environmental regulations are expressly superseded.

  How it illustrates the term: The 2020 act, being the later law, directly overrides and replaces the less stringent 1995 law regarding pollutant discharge. The explicit repeal clause in the newer law ensures that the stricter standards now apply, demonstrating lex posterior derogat priori.

• Taxation Laws: Consider a city ordinance from 2008 that established a flat 1% sales tax on all retail goods sold within its jurisdiction. In 2023, the city council passes a new ordinance that raises the sales tax to 2.5% and, for the first time, exempts certain essential food items from this tax. While the 2023 ordinance doesn't explicitly state, "the 2008 ordinance is repealed," its provisions clearly set a new, different sales tax rate and scope.

  How it illustrates the term: The 2023 ordinance, as the later law, establishes a new sales tax structure that is obviously repugnant to (inconsistent with) the 2008 ordinance's provisions. Because both cannot simultaneously apply, the newer law prevails, setting the current sales tax rules for the city.

• Consumer Protection: Suppose a federal regulation from 1990 required manufacturers to provide a minimum 60-day warranty for all new household appliances. Years later, in 2018, Congress passes a new federal consumer protection act that mandates a minimum 120-day warranty for the same types of appliances and adds new requirements for product safety disclosures. The 2018 act includes a general clause stating that any previous regulations offering less consumer protection are superseded.

  How it illustrates the term: The 2018 act, as the later and more protective law, directly supersedes the 1990 regulation. Consumers are now entitled to the longer 120-day warranty because the newer law, by offering enhanced protection, overrides the older, less stringent requirement.