This phrase is used to signify that the laws of different countries (or other jurisdictions), on the subject-matter to be decided, are in opposition to each other; or that certain laws of the same country are contradictory.

When this happens to be the case, it becomes necessary to decide which law is to be obeyed. This subject has occupied the attention and talents of some of the most learned jurists, and their labors are comprised in many volumes. A few general rules have been adopted on this subject, including:

National Sovereignty

Every nation possesses an exclusive sovereignty and jurisdiction within its own territory. The laws of every state, therefore, affect and bind directly:

  • All property, whether real or personal, within its territory.
  • All persons who are resident within it, whether citizens or aliens, natives or foreigners
  • All contracts made and acts done within it.

Entities Not Bound by the Local Jurisdiction

It is proper, however, to observe, that ambassadors and other public ministers, while in the territory of the state to which they are delegates, are exempt from the local jurisdiction. And the persons composing a foreign army, or fleet, marching through, or stationed in the territory of another state, with whom the foreign nation is in amity, are also exempt from the civil and criminal jurisdiction of the place.

What States Can Regulate

Possessing exclusive authority, with the above qualification, a state may regulate:

  • The manner and circumstances under which property, whether real or personal, in possession or in action, within it shall be held, transmitted or transferred by sale, barter or bequest, or recovered or enforced.
  • The condition, capacity, and state of all persons within it to the validity of contracts and other acts done there.
  • The resulting rights and duties growing out of these contracts and acts.
  • The remedies and modes of administering justice in all cases.

Perfect Independence

A state or nation cannot by its laws, directly affect or bind property out of its own territory, or persons not resident therein, whether they are natural born or naturalized citizens or subjects, or others. This result flows from the principle that each sovereignty is perfectly independent. To this general rule there appears the exception that a nation has a right to bind its own citizens or subjects by its own laws in every place; but this exception is not to be adopted without some qualification.

Whatever force and obligation the laws of one country have in another depends upon the laws and municipal regulations of the latter; that is to say, upon its own proper jurisprudence and polity and its own express or tacit consent. When a statute or common law of the country forbids the recognition of the foreign law, the latter is of no force whatever. When both are silent, the question arises as to which of the conflicting laws is to have effect. Whether one or the other shall be the rule of decision must necessarily depend on a variety of circumstances which cannot be reduced to any certain rule. No nation will suffer the laws of another to interfere with her own to the injury of her own citizens; and whether they do or not depends on the condition of the country in which the law is sought to be enforced, the particular state of her legislation, her policy and the character of her institutions. In the conflict of laws, it must often be a matter of doubt which should prevail; and, whenever a doubt does exist, the court which decides will prefer the law of its own country to that of the stranger.