Does “Not An” Mean “Not Any” or “Not That Particular One”?

Justice Kagan’s opinion this morning in Caraco v. Novo Nordisk has an interesting passage about how context changes meaning. The relevant statute says that a party can bring a counterclaim if “the patent does not claim . . . an approved method of using the drug.” The question before the Court was whether that means that the counterclaim can be brought only if the patent claims no method of using the drug, or only if in doesn’t claim that particular method of using the drug. Justice Kagan writes:

Truth be told, the answer to the general question “What does ‘not an’ mean?” is “It depends”: The meaning of the phrase turns on its context. See Johnson v. United States, 559 U. S. ___, ___ (2010) (slip op., at 5) (“Ultimately, context determines meaning”). “Not an” sometimes means “not any,” in the way Novo claims. If your spouse tells you he is late because he “did not take a cab,” you will infer that he took no cab at all (but took the bus instead). If your child admits that she “did not read a book all summer,” you will surmise that she did not read any book (but went to the movies a lot). And if a sports-fan friend bemoans that “the New York Mets do not have a chance of winning the World Series,” you will gather that the team has no chance whatsoever (because they have no hitting). But now stop a moment. Suppose your spouse tells you that he got lost because he “did not make a turn.” You would understand that he failed to make a particular turn, not that he drove from the outset in a straight line. Suppose your child explains her mediocre grade on a college exam by saying that she “did not read an assigned text.” You would infer that she failed to read a specific book, not that she read nothing at all on the syllabus. And suppose a lawyer friend laments that in her last trial, she “did not prove an element of the offense.” You would grasp that she is speaking not of all the elements, but of a particular one. The examples could go on and on, but the point is simple enough: When it comes to the meaning of “not an,” context matters.

An interesting passage for its professorial style, use of gendered pronouns, and dicta on the Mets. Oh, and for what it’s worth, Justice Kagan reportedly is a Mets fan.