Precedent

Stand by decisions and do not disturb settled matters.

Stare decisis et non quieta movere.

Source: Johnson v. Western Union Tele. Co. (N.C.) 57 S.E. 122, 124; Co. Litt.; Broom, Max.

Stability in the law is essential to liberty — when courts reverse settled principles on every new occasion, no man can know his rights and no contract is secure.

We are to judge by laws, not by examples.

Non exemplis sed legibus judicandum est.

Source: 4 Co. 33b; 4 Bl. Comm. 405

Precedent is a guide, not a master — when a prior decision conflicts with the law itself, the law prevails and the precedent must yield.

Things introduced contrary to the reason of the law ought not to be drawn into precedent.

Quae contra rationem juris introducta sunt, non debent trahi in consequentiam.

Source: 12 Co. 75; Dig. 1, 3, 14; Dig. 50, 17; Weisman, 88e

An aberrant decision — one that contradicts established legal principles — should be confined to its facts and never extended to new cases.

One absurdity being established, an infinity follows.

Uno absurdo dato, infinita sequuntur.

Source: 1 Co. 102; Weisman, 88i

A single bad precedent opens the door to endless subsequent errors — the first departure from sound principle must be corrected before it spawns a chain of injustice.

The old way is the safe way.

Via antiqua via est tuta.

Source: Ex parte Crane, 5 Pet. (30 U.S.) 223; 10 Co. 142; Weisman, 88j

Established practice, tested by time and experience, is more trustworthy than novel theory — innovation in the law should be approached with caution.

Antiquity did nothing without a good reason.

Antiquitas nihil fecit sine ratione bona.

Source: Co. Litt. 65; Weisman, 88l

Before discarding a longstanding legal principle, one should first understand why it was adopted — the presumption is that our predecessors acted wisely.