July 07, 2007

The Supreme Court Fails Semantics

One of the skills expected of judges is the ability to understand specialized legal language; this they are trained to do in law school. It also falls to judges to interpret ordinary language. In this they receive no special training, and, from time to time, fail. The recent US Supreme Court decision in Morse v. Frederick is a case in point.

The case concerns an incident that occurred when students at a high school in Alaska were let out of school to observe the Olympic Torch Relay. A group of students, among them Joseph Frederick, held up a banner with the words "BONG HiTS 4 JESUS". When the principal, Deborah Morse, demanded that they take it down, Frederick refused. As a result he was suspended.

The case raises a number of issues about the free speech rights of high school students that have been the subject of extensive commentary and debate elsewhere. An issue that has not been adequately addressed is what Frederick said that justified punishment. The Supreme Court majority is of the view that the school had the right to punish Frederick for the slogan because it encourages the use of drugs, which it is the policy of the school to discourage. Here is Chief Justice Roberts' majority opinion, in which he was joined by Associate Justices Alito, Kennedy, Scalia, and Thomas, on this point:

The Court agrees with Morse that those who viewed the banner would interpret it as advocating or promoting illegal drug use, in violation of school policy. At least two interpretations of the banner's words - that they constitute an imperative encouraging viewers to smoke marijuana or, alternatively, that they celebrate drug use - demonstrate that the sign promoted such use. This pro-drug interpretation gains further plausibility from the paucity of alternative meanings the banner might bear.

Associate Justice Thomas does not address this issue in his concurring opinion, which is devoted primarily to his view that high school students have no free speech rights and that Tinker should be overturned. Associate Justice Alito in his concurring opinion explicitly limits the school's power to forbidding advocacy of illegal drug use, stating that advocacy of the legalization of the use of marijuana, for example, would fall within the student's First Amendment rights.

Thus, a critical element of the Court's decision is the claim that "BONG HiTS 4 JESUS" is properly interpreted as advocating the illegal use of marijuana. Frederick, on the other hand, asserts "that the words were just nonsense meant to attract television cameras". His explanation is supported by the playful, irregular capitalization of "HiTS" and the use of "4" in lieu of "for", as well as by the inclusion of the PP "for Jesus", which makes no sense here but is a common component of the slogans of the religious right and so is incongruous in combination with "bong hits".

If an utterance is well-formed we arguably don't need to engage in any kind of linguistic analysis to find out what it means: any fluent speaker of the language will know. I say arguably, because even fluent speakers may not realize without thinking about it or unless someone else points it out, that more than one interpretation is possible. Not only may they miss structural ambiguities, they may not know some possible meanings of some words, or these meanings may not be salient for them.

In this case, however, we have a legal controversy, between fluent native speakers, as to the meaning of the utterance. Even those who purport to know that it encourages illegal drug use tacitly admit that it does not wear this meaning on its face. The utterance is peculiar and requires a process of inference to interpret. In such a case, we can't simply rely on the claims of fluent speakers but must carry out an analysis of the utterance to determine its possible meanings.

I submit that there are two serious errors in the Court's analysis. The first is that it is unwilling to accept the possibility that the utterance is meaningless. Justice Roberts writes:

The dissent mentions Frederick's "credible and uncontradicted explanation for the message - he just wanted to get on television"... But that is a description of Frederick's motive for displaying the banner; it is not an interpretation of what the banner says.

This begs the point. No "interpretation of what the banner says" could be offered by Frederick insofar as it has no meaning. By dismissing any explanation for what was written on the banner that does not provide an interpretation, the Court assumes that it must mean something. Nowhere in the opinion is any justification offered for this assumption.

That it is perfectly possible for a well-formed utterance to have no semantic interpretation is well known to linguists. The classic example is the sentence:

Colorless green ideas sleep furiously.

put forward by Noam Chomsky in Syntactic Structures. In An Inquiry into Meaning and Truth (1940, Ch. XII) Bertrand Russell used the example:

Quadruplicity drinks procrastination.

That an ill-formed or incomplete utterance might have no semantic interpretation is of course completely uncontroversial.

Thus, from a linguistic point of view, it is perfectly possible that the words on the banner might have meant nothing at all. Frederick's explanation of his motivation for displaying the banner provides a plausible account of his use of words that did not mean anything.

The other error in the Court's analysis is in mistaking one kind of meaning for another. The modern study of meaning is based on the assumption that the meaning of a complex expression can, in general, be computed from the meanings of its components. To make an exhaustive analysis of the possible meanings of "BONG HiTS 4 JESUS", we would determine the possible meanings of each of the individual words, what the possible syntactic structures are, and what overall meanings can be computed from the meanings of the words when inserted into the possible syntactic structures. Doing this would be quite tedious, and very few combinations are at all plausible, so I'll assume that "BONG HiTS" is a compound noun referring to inhalations of marijuana and that "4 JESUS" is a prepositional phrase meaning "for the benefit of a person named Jesus", most likely the famous one, but conceivably someone else. If the slogan is a single syntactic constituent, it must be a Noun Phrase in which "for Jesus" modifies "bong hits".

There are a number of types of meaning. When we talk about the meaning of a noun, we are normally concerned with its denotation, that is, with the set of things to which it refers. The word dog, for example, denotes the set of dogs. Sentences, on the other hand, typically express propositions, such as "Roses are red." and "Beavers build dams.".

The kind of meaning that the Court purports to find is propositional. It claims, in effect, that the interpretation of the banner is something like "It is good to smoke marijuana even though it is illegal." or "Go ahead and smoke marijuana.". However, the banner does not, on any plausible analysis, contain the kind of syntactic structure that serves to express propositions, namely a sentence, not even a sentence part of which is not overt. Nor is this an example of a construction with an implicit verb, such as "Freedom for Tibet", which means something like "Freedom for Tibet would be good" or "We support freedom for Tibet". (The Court does not argue that the banner means "It would be good for Jesus to smoke marijuana.")

All that the Court actually argues is that "BONG HiTS 4 JESUS" contains a reference to drug use.

Gibberish is surely a possible interpretation of the words on the banner, but it is not the only one, and dismissing the banner as meaningless ignores its undeniable reference to illegal drugs. [emphasis mine]

That is probably true, but a reference is not a proposition and does not support any inference as to the speaker's attitude toward smoking marijuana. Even if the banner said "smoking marijuana" we could not say whether it meant "Smoking marijuana is hazardous." or "Smoking marijuana is delightful." or something else.

In sum, from the observation that the banner contains a reference to smoking marijuana, and the false assumption that the banner must express a proposition, the Court has invalidly inferred a particular proposition. The slogan is in fact meaningless in the sense that it expresses no proposition, and Frederick gave a perfectly plausible explanation for the use of a meaningless slogan. The Court was therefore wrong in finding that the banner advocates the use of marijuana.

Posted by Bill Poser at July 7, 2007 05:09 AM