Ordinary Language Philosophy in Supreme Court Gun Case (updated)

What is a weapon? That question was the focus of a recent US Supreme Court decision, Bondi v. Vanderstock. 

At issue was whether the Gun Control Act of 1968 (GCA) applies to kits comprised of parts designed for individuals to assemble into functional firearms themselves.

The GCA “requires those engaged in importing, manufacturing, or dealing in firearms to obtain federal licenses, keep sales records, conduct background checks, and mark their products with serial numbers.”

The background to the case is as follows. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) decided in 2022 that GCA did cover build-a-gun kits, a decision that was challenged in court by gun manufacturers and others. The lower and appellate courts agreed with the gun manufacturers that the ATF’s decision was “facially inconsistent” with the GCA.

The Supreme Court disagreed, holding that there is nothing inconsistent with the GCA applying to the weapons kits. (The ruling is just on that narrow question; not on the legality of the substantive applications of the GCA to the kits.)

In laying out its reasoning, the court appealed to the way we ordinarily use words, and cited an essay, “Law” by philosophers Jules Coleman (Constructor University) and Ori Simchen (University of British Columbia), that appeared in Legal Theory in 2003, and “The Progressive in English” by Terence Parsons (1923-2022) in Linguistics and Philosophy, among other works.

Here’s the Court:

Take a weapon parts kit featured prominently in the record before us: Polymer80’s “Buy Build Shoot” kit. It comes with “all of the necessary components to build” a Glock-variant semiautomatic pistol. App. to Pet. for Cert. 219a. And it is so easy to assemble that, in an ATF test, an individual who had never before encountered the kit was able to produce a gun from it in 21 minutes using only “common” tools and instructions found in publicly available YouTube videos. Id., at 220a. The first picture below shows the kit; the second depicts the gun the kit yields.

Now, assess whether the “Buy Build Shoot” kit meets subsection (A)’s two tests, and start with the question whether Polymer80’s offering qualifies as a “weapon.” When Congress adopted the GCA in 1968, that term meant what it means today: “an instrument of offensive or defensive combat . . . [such] as a club, sword, gun, or grenade.” Webster’s Third New International Dictionary 2589 (def. 1) (1966); accord, 1 Concise Oxford English Dictionary 1476 (def. 1) (5th ed. 1964). As a result, ATF’s authority under subsection (A) extends only to instruments of combat, not to other things like industrial tools or toy guns that may “expel a projectile by the action of an explosive.” It is a feature of the statute the agency itself has long acknowledged. See 87 Fed. Reg. 24684.

Plainly, the finished “Buy Build Shoot” kit is an instrument of combat. No one would confuse the semiautomatic pistol pictured above with a tool or a toy. Of course, as sold, the kit requires some assembly. But a number of considerations persuade us that, even as sold, the “Buy Build Shoot” kit qualifies as a “weapon.”

Consider, first, a feature of ordinary language. The term “weapon” is an artifact noun—a word for a thing created by humans. Artifact nouns are typically “characterized by an intended function,” rather than by “some ineffable ‘natural essence.’ ” S. Grimm & B. Levin, Artifact Nouns: Reference and Countability, in 2 Proceedings of the 47th Annual Meeting of the North East Linguistic Society (NELS 47) 55 (2017).[fn3] Reflecting as much, everyday speakers sometimes use artifact nouns to refer to unfinished objects—at least when their intended function is clear. An author might invite your opinion on her latest novel, even if she sends you an unfinished manuscript. A friend might speak of the table he just bought at IKEA, even though hours of assembly remain ahead of him. In both cases, the artifact noun fits because the intended function of the unfinished object is obvious to speaker and listener alike.

The term weapon can work this way, too. Imagine a rifle disassembled for storage, transport, or cleaning. It may take time to render the rifle useful for combat, but its intended function is clear. And, as a matter of every day speech, that rifle is a weapon, whether disassembled or combat ready. In the same way and for the same reason, an ordinary speaker might well describe the “Buy Build Shoot” kit as a “weapon.” Yes, perhaps a half hour of work is required before anyone can fire a shot. But even as sold, the kit comes with all necessary components, and its intended function as instrument of combat is obvious. Really, the kit’s name says it all: “Buy Build Shoot.” 

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[fn3] Accord, Brief for Professors and Scholars of Linguistics and Law as Amici Curiae 6–9; J. Pustejovsky, The Generative Lexicon 97 (1995); J. Coleman & O. Simchen, “Law,” 9 Legal Theory 1, 20 (2003); T. Parsons, The Progressive in English, 12 Linguistics in Philosophy 213, 225226 (1989). 

Justices Roberts, Sotomayor, Kagan, Gorsuch, Barrett, and Jackson signed onto the majority opinion; Kavanaugh concurred; Thomas and Alito dissented.

You can read the whole decision here.

(via Christopher Stephens)

UPDATE (4/10/25): Philosophers were also involved in this case via an amici brief and article. The brief, on the linguistics of artifact nous, was written by a group of scholars led by Brandon Waldon (currently at Georgetown, but soon to be at the South Carolina in philosophy and linguistics). The article, “Reading Law with Linguistics: The Statutory Interpretation of Artifact Nouns” is by Waldon, Cleo Condoravdi (Linguistics, Stanford), James Pustejovsky (Linguistics & Computer Science, Brandeis), Nathan Schneider (Linguistics & Computer Science, Georgetown), and Kevin Tobia (Law & Philosophy, Georgetown). Professor Tobia alerted me to this, and pointed out that it’s unusual for amicus briefs to be cited in decisions, and it is very unusual for an opinion to “draw[] heavily from an amicus brief,” as Justice Thomas’s dissent in the case alleges.