The standard of review analysis for judicial review of administrative action developed over the course of four decades by the Supreme Court of Canada had two important features. First, it provided something of a bulwark against interventionist judges, thereby protecting the autonomy of administrative decision-makers and promoting deference. Secondly, it was unrelentingly substantive, rather than formal, and moved the focus of judicial review away from abstract concepts and towards the eccentricities of statutory schemes. However, in its more recent forays into the general principles of judicial review, the Court has threatened to reverse its deferential and substantive course by following a formalistic, categorical approach rather than the standard of review analysis. In this article I will describe the Court’s efforts to reshape the law of judicial review of administrative action in two important recent cases, I will critique these efforts as favouring a formalistic approach to judicial review, and I will suggest that in its haste to simplify the law of judicial review, the Court has jeopardized the according of due deference to administrative decision-makers and erroneously favoured form over substance.