The Causation Canon

It is rare to witness the birth of a canon of statutory interpretation. In the past decade, the Supreme Court created a new canon—the causation canon. When a statute uses any causal language, the Court will assume that Congress meant to require the plaintiff to establish “but for” cause. This Article is the first to name, recognize and discuss this new canon. The Article traces the birth of the canon, showing that the canon did not exist until 2013 and was not certain until 2020. Demonstrating how the Court constructed this new canon yields several new insights about statutory interpretation.The Supreme Court claimed the new causation canon represents “ancient” and “long-held” principles of common law. The Supreme Court’s claims about the causation canon are easily disprovable with only a cursory re-view of Supreme Court cases from the past 40 years. This is not a case of a contested or difficult historic record.With the causation canon the Court did not simply apply the common law to statutes. Instead, it created its own new federal causation standard that is not consistent with any state’s common law or even the Restatement of Torts. The Court significantly changed the common law and then magnified the significance of the change by imposing it as a default statutory interpretation canon that will apply across both federal civil and criminal statutes. This new canon represents a significant change in the way the Supreme Court has used the common law, and it does not fit comfortably within claims made about textualism generally or substantive canons specifically. Creating a new federal common law of factual cause and imposing that newly created law as a default standard significantly raises the profile of this area of statutory interpretation and demands greater scholarly inquiry