Legal Definitions - extra commercium

Extra commercium is a Latin phrase meaning "outside commerce." It refers to things that, by their nature or legal designation, cannot be privately owned, bought, or sold. These are typically items or resources considered essential for public use or benefit, or those that are inherently part of the public domain and therefore belong to everyone collectively, rather than to any individual or private entity.

Here are some examples to illustrate this concept:

• A Public Highway: Imagine a major interstate highway that crosses several states. While vehicles use it daily and businesses operate along its routes, no individual or private company can purchase a segment of the highway itself to charge private tolls or restrict access. The highway is built and maintained by the government for the public good, making it extra commercium because it is not subject to private ownership or commercial transaction.

• The Air We Breathe: Consider the atmosphere above a city. Despite its vital importance for all living beings, no one can claim private ownership of the air itself. While regulations exist for air quality or emissions, the fundamental resource of breathable air is considered a common good, not a commodity to be bought and sold by private parties. It exists extra commercium, beyond the realm of private property and commercial exchange.

• A National Monument or Historic Site: Think of a famous national monument, such as the Statue of Liberty or a protected historical battlefield. These sites are preserved and maintained by the government for the benefit and enjoyment of all citizens, representing shared cultural heritage. They cannot be purchased by a private collector or corporation, nor can their ownership be transferred. Their status as public heritage places them extra commercium, outside the market for private property.