There's an old, and all too accurate, way to categorize a particular variety of inexcusable ignorance: If one speaks three languages, one is trilingual; if one speaks two languages, one is bilingual; and if one speaks only one language, one is an American. And so, for today, we'll turn to another website for our actual text:
Principles are not instantiations of a universal moral law, but the product of local political, cultural, and historical circumstances. Without a deep study of foreign legal, political, and social systems--a study that few Americans have made or are capable of making--it is impossible to determine whether a foreign-language statement is the product of a reasoning process, values, ideology, or other circumstances that are the same or similar in the United States.
Oops. I seem to have edited for a nefarious purpose there. What Judge Posner actually said was:
Second, legal principles are not instantiations of a universal moral law, but the product of local political, cultural, and historical circumstances. Without a deep study of foreign legal, political, and social systems--a study that few U.S. judges or justices, or for that matter academics, have made or are capable of making--it is impossible to determine whether a foreign decision on gay marriage, abortion, hate speech, capital punishment, religious establishments, etc. is the product of a reasoning process, values, ideology, or other circumstances that are the same or similar in the United States. Gay marriage is the most obvious current example. The opposition to it in the United States is largely though not entirely religious in origin, and so in countries that are much less religious than the U.S. opposition is muted; but this says nothing about whether the U.S. position is "wrong" because out of step with these other countries.
"Citing Foreign Courts," Leiter Reports (28 Dec 04) (guest blawgger).
I think Judge Posner's objection has some validity, but is stated far too broadly (go read the whole entry). I think he misses the point of legal citation—or, rather, the intellectually honest point. Judge Posner's third objection—that many citations to foreign sources in US judicial opinions are nothing more than "figleafing" for the judge's judge's wet-behind-the-ears clerk's emperor's nakedness, has far more force to it than one might otherwise expect. Unfortunately, it is not limited to US law by any means; too many judicial opinions (and briefs, and everything else) contain string-cites of dubious applicability to prove that a thought has value precisely because it is unoriginal; that somebody else has said something similar enough before in some other (not necessarily congruent) context that the writer can put the burden on that predecessor; in short, that logic and pragmatism have little or nothing to do with the resolution of disputes short of bloodshed. So, in that sense, Judge Posner's third objection is if anything understated when considering citations as precedent, proof of precedent, or whatever. His objections, however, are greatly overstated in the opposite sense: Citations to authority provide a helpful context to the reader to understand not the force, but the source, of the reasoning.
As I understand Judge Posner's blawg entry—and great thanks to both his participation and Professor Leiter's offer of a forum—his objection is to use of foreign decisions as "precedent." That, however, begs an entirely different question: Is every citation in a legal opinion to precedent, whatever the hell that means? In an intellectually honest universe, this cannot be correct. There is no content without context; some of those citations necessarily establish context, not content (in a logical sense, are more akin to first cause than to proximate cause); most importantly—and particularly in opinions from a court from which there is no further possible appeal—citations to foreign law avoid legal Balkanization by at least recognizing the possibility of alternative viewpoints. Consider the Erie problem, which is equally an issue of "foreign law," and I think you'll see exactly why Judge Posner's position on foreign legal citations needs some revision. Or, better yet, look at any contract law casebook or hornbook, or look at the Restatement (2d) of Contracts § 178(2)(c) (comm. e, ill. 18, 19). Most states' "common law" of contracts adopts a considerable portion of the substantive contract law of New York; comparative negligence theory was adopted largely in by reliance on the California Supreme Court's development of that doctrine; and so on. As Judge Posner should well know, being based in Chicago, there's no guarantee that the political machine in State A produces law that is "the product of a reasoning process, values, ideology, or other circumstances that are the same or similar in" State B. And, if you need any further examples, just compare Louisiana's Napoleonic code to the English common-law foundation in the rest of the country; or the community-property states of the West to the rest of the country; or…
My point is this: That Judge Posner has, I think, figleafed his own argument behind the emotionally loaded term "precedent." The assumption that every citation in a judicial opinion, or indeed in any work, is to "precedent" or some other authority that somehow compels a particular conclusion (even a tiny conclusion that is part of a much larger argument) is, or at least should be, an improper one. Although Judge Posner specifically mentions gay marriage, I think the current controversy has actually been driven by the Supreme Court's recent jurisprudence on the death penalty, much of which cited foreign treaties and judicial decisions for assistance in defining terms in our own Constitution—terms purposefully left vague. If it is indeed a Constitution that we are expounding, this is inevitable; in fact, it would be a dereliction of duty for judicial officers (both judges and their clerks) to reject out of hand any large class of sources that might improve the accuracy of the interpretive process. One must keep in mind, too, that judicial opinions—and most particularly those from the highest courts—cannot be written solely for lawyers to use as foundations for future litigation. Instead, they must be written to enable ordinary citizens to conform their conduct to the law's requirements. (That alone should be the death of the string cite; but it's not going to be. Unfortunately. Swift was far too prescient.)