It is best not to unsettle things which are originally established.

Explanation

(English-origin maxim.) Established legal principles should not be lightly disturbed — stability in the law is a value in itself, and settled rules should be overturned only for compelling reasons.

Where this applies

• A court refuses to overturn a century-old property-rights doctrine just because a new legal theory has become fashionable.
• A legislature considers repealing a long-standing consumer-protection law but decides against it because stability in the law is valuable and the law has worked well.
• A bar association opposes frequent changes to the rules of professional conduct, arguing that settled rules should not be disturbed without strong justification.