Application is the life of a rule.

Explanation

A rule that is never applied is dead letter — rules exist to govern actual cases, and their meaning is known only through their application to real facts.

Where this applies

• A legal rule has never been applied to an actual case.
• Someone argues that a rule should be tested in practice before being relied on.

See also

• 1.5.14 The law does not arise from the rule, but the rule from the law.
• 1.5.18 It is better to seek the source than to follow the streamlets.