Legalviews Personal

In 2022, the Supreme Court of Canada’s Sullivan decision (2022 SCC 19) stated that a judge should ordinarily follow the ratio decidendi of a precedent from the same court, even if the present judge thinks it mistaken. That is called horizontal stare decisis. It applies even to constitutional questions and unconstitutionality of statutes (¶ʼs 44, 48, 53, 58-59, 68, 79.) But it is limited to courts and judges in the same province (¶ʼs 56, 65, 66, 68). There is little point to discussing whether or not that is a wise principle. But knowing what it does and does not mean, is very important. A recent King’s Bench decision gives such useful advice.

This 2026 King’s Bench decision by one Justice was not a first decision. It was an appeal from a decision by an Applications Judge. The justice said that that made a difference. The appeal exists to correct errors by the Applications Judge. Not merely to ask whether the Applications Judge had been required by precedent to adopt those errors (¶ʼs 34-49 of the 2026 decision). The appeal from the Applications Judge is not a second first-instance decision. Given how appeal courts work, that is plainly correct. And a precedent from a lower level of court or judge does not bind a justice of a higher court (¶ʼs 40 ff.)

This 2026 decision also discusses the force and limits of horizontal precedents. Consistency of law and its good effects mean that same-level precedents should get some weight, and that the issue is not whether this judge likes a previous legal decision by another judge of the same court (¶ 32). The 2012 Supreme Court of Canada decision in Sullivan (in its ¶ʼs 74-78) names three exceptions to horizontal stare decisis: later overruling by a higher court, the earlier precedent being “per incuriam”, and the earlier precedent not being fully considered (2026 decision, ¶ 60). Per incuriam (carelessness or inadvertence) includes not following a still earlier higher-level precedent (¶ 62). And it includes not seeing whether one same-level precedent had been confirmed on appeal (¶ 72). (Probably it would also include overlooking relevant legislation.) I think that per incuriam is not that rare. Some counsel cite incomplete or erroneous authorities. Some counsel do not really know how or where to research the law. Use of Artificial Intelligence will not improve that situation. A justice must handle oft-arising issues in morning chambers by rules of thumb. But those are sometimes not completely accurate, or have exceptions.

The exception for “not fully considered” is not discussed in this recent decision. But where a sole horizontal precedent was given orally on the spot without reserving decision, especially in chambers, not after a trial, this exception is important. And doubly important on a procedural application without written briefs. Alberta’s King’s Bench produces a lot of careful reserved decisions where some time has been taken and counsel have looked up the law and thought about it. But chambers lists are often very crowded, and it is impossible to reserve decision on the great majority of such applications. Sometimes counsel argue only one or two issues, and let other necessary reasoning steps or issues go by assumption or silence.

The recent decision is Babcock v. Thuro 2026 ABKB 615 (Sep 3).

– Hon. J.E. Côté

WHEN DOES ONE JUDGE IMPOSE BINDING LAW ON ALL THE COURT?