What is introduced of necessity is never introduced except when necessary.

Explanation

The exception of necessity is self-limiting; it arises only when the necessity is present and ceases the moment it is no longer required.

Where this applies

• The emergency exception only applies when the emergency actually exists.
• What is introduced by necessity ceases the moment it's no longer needed.
• Emergency measures are self-limiting — they expire with the emergency.

See also

• 12.6.1 Necessity has no law.
• 12.6.2 A good thing required by necessity is not good beyond the limits of the necessity.