The end of the Supreme Court's term usually brings divided decisions. But in Southwest Airlines Co. v. Saxon, the whole Court agreed on both the result and the reasoning in a trim 11 pages.

Why the unanimity? Southwest Airlines required the Court to interpret the Federal Arbitration Act, and it used an interpretive framework that has broader value for other statutory problems.

The Federal Arbitration Act does not apply to "contracts of employment of seamen, railroad employees, or any other class of workers engaged in foreign or interstate commerce." 9 U.S.C. § 1. The respondent in Southwest Airlines, Latrice Saxon, worked at an airport as a Ramp Supervisor. Although Saxon was a supervisor, she alleged that her job involved loading and unloading cargo that moved in interstate commerce. Saxon herself stayed in one place.

To decide whether the Act exempted workers like Saxon, the Court started—"as always"—with the statute's text. Looking for the "ordinary, contemporary, common meaning" of that text, the Court opened several 100-year-old dictionaries. Each suggested that people who load and unload cargo are "part of the interstate transportation of goods."

When the Supreme Court says "always" start with the text, it means it. Dictionaries (written when the statute was passed, if possible) should be the first resort. Grammar, usage rules, and even punctuation also matter. The Court is asking what the words of the statute say.

But ordinary meaning does not stop with dictionaries or grammar rules. Instead, the Court explained, "words must be read and interpreted in their context, not in isolation." In Southwest Airlines, that meant using two contextual canons of interpretation.

First, the meaningful-variation canon told the Court that the narrow phrase "engaged in commerce" should be read differently from broader phrases like "affecting" or "involving" commerce. Second, the ejusdem generis canon told the Court to read the catch-all category of other "workers" as sharing "common attributes" with the more specific words "seamen" and "railroad workers" in the same list. The Court found that cargo loaders, seamen, and railroad workers all play a direct role in moving commerce across borders.

Contextual canons like these are often just codified common sense. They lend authority to arguments about how to take meaning from context, and able advocates know how to use them. But other context can matter too. Different parts of the statute, for example, can help explain the overall statutory scheme. So can legislative history. A lawyer facing a statutory interpretation problem should consider every angle.

In Southwest Airlines, the text and context of the Federal Arbitration Act pointed the same way. The Court unanimously held that workers who load and unload cargo are "engaged in foreign or interstate commerce." As a result, the airline could not force Saxon to arbitrate under the FAA. (Still pending before the district court is a motion to compel arbitration under state law.)

Statutory problems aren't always so easily solved. Sometimes text is less clear and context less helpful. But the interpretive framework that the Court uses in Southwest Airlines is still a good place to start.