The doctrine of stare decisis is the guardian of the development of stable general principles of law. The phrase “stare decisis” is the abbreviation of a longer Latin phrase which means “to stand by decisions and not to disturb settled matters.” The doctrine is a cornerstone of the Canadian hierarchical system of justice which comprises (1) the Supreme Court of Canada, (2) each provincial appeal court, and (3) each provincial trial court.
The decisions of each court in the hierarchy are binding on each court below it and must be followed. The Supreme Court of Canada has exclusive appellate civil and criminal jurisdiction across Canada and its decisions must be followed by all provincial appeal and trial courts. Even comments in a decision by the Supreme Court which are not fundamental to its decision have a binding force on all lower courts. The decisions of each provincial appeal court are also binding on all courts below it in the province. However, they are not binding in other provinces although they are often given the same respect. It has been stated that there can be no stare decisis between judges of the same court and that they follow the judgments of others in the same court as a question of judicial collegiality where the facts are identical or similar. Nevertheless, they cannot ignore applicable decisions and, if they refuse to follow them, they must provide strong reasons for declining.
The basic principle of the doctrine is that judges sit in court, not with the right to give judgment according to what their individual opinion is as to what the law ought to be, but to give judgment according to what they find stated by authorities whose opinions are binding upon them. Without the uniform and consistent adherence to these authorities, the administration of justice would become disordered, the law uncertain, and the confidence of the public in it undermined.
Notwithstanding this noble sentiment, it is now commonly accepted that the Supreme Court of Canada and provincial appeal courts may overturn their previous decisions where there are compelling reasons for doing so and they have exercised their discretion on a number of occasions.