We are to adhere to precedents, and not to unsettled things which are not established.

Explanation

(English-origin maxim.) Courts should follow established precedents and avoid reliance on unsettled or novel propositions — stability and predictability in the law are essential to liberty.

Where this applies

• A judge follows a well-established line of Supreme Court cases rather than adopting a novel interpretation proposed by a law professor's article.
• An appellate court declines to adopt an untested legal theory and instead applies the settled precedent that has guided lower courts for decades.
• A trial judge applies longstanding case law on contract interpretation rather than relying on a new and unproven approach suggested by one of the parties.