Stare Decisis Definition:

A basic principle of the law whereby once a decision (a precedent) on a certain set of facts has been made, another Court of the same rank or lower, must apply that decision in cases presenting the same set of facts.

The precedent becomes binding and must be followed by courts of like rank.

Extracted from Stuart v Bank of Montreal (1916):

"To say that the decisions are wrong in point of principle, if that principle was clearly laid down, does not relieve us from the obligation of following the principle of the decision, because the whole theory of our system is that the decision of a superior court is binding on an inferior court and on a court of co-ordinate jurisdiction so far as it is a statement of the law which the court is bound to accept....

"Little respect will be paid to our judgments if we overthrow that one day which we have resolved the day before."

The adherence to stare decisis is not absolute, as these two USA cases, in chronological order, demonstrate:

1.  Vasquez v Hillery (1986):

“Today's decision is supported, though not compelled, by the important doctrine of stare decisis, the means by which we ensure that the law will not merely change erratically, but will develop in a principled and intelligible fashion. That doctrine permits society to presume that bedrock principles are founded in the law rather than in the proclivities of individuals, and thereby contributes to the integrity of our constitutional system of government, both in appearance and in fact. While stare decisis is not an inexorable command, the careful observer will discern that any detours from the straight path of stare decisis in our past have occurred for articulable reasons, and only when the Court has felt obliged to bring its opinions into agreement with experience and with facts newly ascertained."

2.   Lawrence v Texas (2003)

“Today's approach to stare decisis invites us to overrule an erroneously decided precedent (including an intensely divisive decision) if its foundations have been eroded by subsequent decisions; it has been subject to substantial and continuing criticism; and it has not induced individual or societal reliance that counsels against overturning."

For a compelling critique of stare decisis in poetry form, see The Stare Decisis Calf Path.

References:

• Duhaime, Lloyd, Poetic Justice: Law Poems, The Stare Decisis Calf Path
• Lawrence v Texas 539 US 558 (2003)
• Stuart v Bank of Montreal 41 SCR 516 (Canada, 1909)
• Van Kleeck v Ramer 156 P. 1108 (1916)
• Vasquez v Hillery 474 US 254 (1986)