The Supreme Court and Foreign Sources of Law: Two Hundred Years of Practice and the Juvenile Death Penalty Decision

171 Pages Posted: 11 Apr 2005

Date Written: April 2005


The legitimacy of citation to foreign sources of law generated comment in all three of the Supreme Court opinions written in Simmons v. Roper, the landmark case that recently struck down the juvenile death penalty. Justice Kennedy's majority opinion and Justice O'Connor's dissent in Simmons, both argued that foreign sources of law can in fact be relevant to issues before the Court, even though they ultimately reached different conclusions as to the constitutionality of the juvenile death penalty. In addition, Justice Scalia's dissent, joined by Chief Justice Rehnquist and Justice Thomas, forcefully declared, as Justice Scalia has repeatedly done in previous Eighth Amendment cases, that international law and opinion is not relevant to the Court's constitutional adjudications, even when it is used simply to provide evidence of the validity of the Court's opinion.

Justice Kennedy's majority opinion in Lawrence v. Texas, which declared unconstitutional state laws prohibiting homosexual sodomy, in part, by considering decisions of the European Court of Human Rights, brought the issue of the Supreme Court's consideration to center stage. But, Justice Kennedy's opinion in Simmons stands to move the debate to an even higher level of attention and importance. By citing foreign sources of law as further support for the Court's own views of what punishments violate the Eighth Amendment, the Simmons Court showed what may be at stake in the outcome of this debate between the six liberal justices and the three conservatives led by Justice Scalia. The depth of the support for citing foreign sources of law suggests that the movement to do this is just beginning and will only gather force over time. In the wake of Simmons, the debate on the Court is no longer over whether to cite foreign sources of law but over when and how to cite them. This portends a sea change in the Court's doctrine.

Two months prior to the Court's decision in Simmons, Justices Antonin Scalia and Stephen Breyer met at American University to debate The Relevance of Foreign Law for American Constitutional Adjudication, thus showing again how important this issue is to the nine sitting Supreme Court justices. In addition to Justice Breyer's public support for citing foreign sources of law in U.S. Supreme Court decisions and Justice Scalia's deep-seated opposition to the practice, other Justices have also made public statements about the legitimacy of citation to such sources. In a 2004 speech at Georgetown Law School, Justice Sandra Day O'Connor went out of her way to voice approval of citation to foreign sources of law in U.S. courts, noting that it can be a help in our search for a more peaceful world, and stating that international law is no longer a specialty ... it is vital if judges are to faithfully discharge their duties. Justice O'Connor also said that while ultimately we must bear responsibility for interpreting our own laws, there is much to learn from other distinguished jurists who have given thought to the same difficult issues that we face here. At a recent national convention of the American Constitution Society, Justice Ruth Bader Ginsburg stated that the Justices are becoming more open to comparative and international law perspectives, and she told the group of judges, lawyers, and students, that we are the losers if we do not both share our experiences with, and learn from others. Justice Ginsburg's support for looking to foreign sources of law was also apparent in her concurring opinion in Grutter v. Bollinger, where she noted that the Court's observation that race-conscious programs must have a logical end point accords with the international understanding of the office of affirmative action and where she cited the International Convention on the Elimination of All Forms of Racial Discrimination, a convention the United States ratified in 1994.

The use of foreign sources of law is often thought to be an issue that creates a clear division between conservative and liberal justices on the Supreme Court. This is due, in part, to the strong opposition to the use of foreign sources of law in constitutional adjudication of two conservative Supreme Court Justices, Justices Scalia and Thomas, and the loud resistance of many conservative commentators and politicians. However, this is not an issue that necessarily divides quite so neatly along political lines. Chief Justice Rehnquist, though he did join Justice Scalia's dissents in Lawrence v. Texas and Simmons v. Roper, once stated that now that constitutional law is solidly grounded in so many countries, it is time that the United States courts begin looking to the decisions of other constitutional courts to aid in their own deliberative process. Moreover, as we discuss below, Chief Justice Rehnquist is the author of a major opinion in the assisted suicide case, Washington v. Glucksberg, which cites and discuss how the practice of assisted suicide has led to abuses in the Netherlands. Justices Scalia and Thomas joined Glucksberg without commenting on its citation to foreign legal practices on assisted suicide.

In addition, although the Court has most recently cited foreign sources of law in support of the liberal outcomes of banning the execution of juveniles and promoting gay rights, citation of foreign sources of law in other areas could lead to many outcomes conservative would favor. For example, on the key hot-button issue of abortion, foreign nations have policies that are much more restrictive overall of abortion rights than does the United States. Although, most European nations have legalized abortion, most restrict its availability to approximately the first twelve weeks of gestation, rather than allowing abortion on demand until viability as is the practice in the United States. In fact, the United States is one of only six countries worldwide that allows abortion on demand until the point of viability.

Legal scholars have played a big role in this fight by urging the Supreme Court to pay more attention to foreign and international sources of law in its decision-making, with academics such as Professor Harold Koh at the vanguard of the movement to encourage U.S. courts to pay more attention to international trends. Others have argued strongly against the practice, including Roger P. Alford, who criticizes the Court's reliance on foreign sources of law in cases of constitutional interpretation as being illegitimate. The debate over the Supreme Court's use of foreign sources of law has not, however, been relegated solely to the justices and to legal academics. The debate has grown into an issue that leads to both fear and applause in the general public at large, and it has created quite a stir in the news media and political arenas, including a heated, ongoing conversation about the issue on some interactive websites. Those who steadfastly oppose citation to foreign sources of law have succeeded in focusing attention on the issue, and two Congressmen recently introduced a resolution on the subject in the House of Representatives. Their resolution, entitled the Reaffirmation of American Independence Resolution, would specifically provide that judicial determinations regarding the meaning of the laws of the United States should not be based on judgments, laws, or pronouncements of foreign institutions unless such foreign judgments, laws, or pronouncements inform an understanding of the original meaning of the laws of the United States.

There has been a lot of debate over the last several years regarding the propriety of the Supreme Court's citation of foreign sources of law, and a recurring argument that has been made is that the current Court's present practice of citing such law is unprecedented. Strikingly, however, none of the participants in this debate has yet stopped to closely examine just what exactly the practice of the Supreme Court has actually been over the past two hundred-plus years of its history in regards to citing foreign sources of law. This Article tries to fill that gap by describing what the Supreme Court's practice has actually been from 1789 to 2005 with respect to citing foreign sources of law. We will show that the Court's citation of foreign sources of law in recent years is not unprecedented as Justice Scalia implies, but that citation to foreign sources of law is increasing in the modern era in ways that may be very problematic. We show that there have been some dramatic, if not notorious, instances of the Court citing foreign sources of law historically, as happened for example in the Dred Scott case and in the anti-polygamy case, Reynolds v. United States. Moreover, we will show that the debate over citing foreign sources of law in American judicial decisions is not a new one at all. Indeed, the practice was debated as early as 1820 when Justice Livingston, in a sentiment echoed many years later by Justice Scalia, responded to Justice Joseph Story's citation of foreign sources of law in a Supreme Court case to provide a definition for the crime of piracy, by stating that it it is not perceived why a reference to the laws of China, or to any other foreign code, would not have answered the purpose quite as well as the one which has been resorted to. Thus, Scalia's modern lament finds an echo as long ago as 1820 in the U.S. reports.

This Article does not seek to answer the question of whether the Supreme Court should cite foreign law sources, a question Professor Calabresi has already addressed in another context. Rather, we seek here to address the issue at a much more fundamental and basic level, which is, what has the Supreme Court's actual historical practice been from 1789 to 2005 in citing foreign sources of law? This article thus examines the many instances between 1789 and 2005 in which the Court has cited foreign sources of law and points out that several themes become apparent. First, on some occasions, the Court cites such sources as evidence of the reasonableness of its decisions: foreign practice is reviewed as to whether an American practice is reasonable or unusual. Second, we think it is striking that the three Justices who have historically been most likely to cite foreign sources of law in their opinions, Justices Joseph Story, Felix Frankfurter, and Stephen Breyer, were all, at some point in their careers, professors at Harvard Law School. This suggests a Harvard nexus to the debate over citation of foreign sources of law, which has gone previously unobserved.

This Article proceeds with its rather ambitious goal of summarizing the Supreme Court's actual practice with respect to citing foreign sources of law in the following manner. Parts II through V compile and examine some of the most striking and significant cases in which the Supreme Court has made reference to foreign sources of law throughout its history. Each Part covers a time frame of approximately fifty years, starting with first half century under the Constitution and ending with the modern period. These four fifty year Parts are then further subdivided according to the types of cases that cite foreign sources of law in each historical period. Thus, Part II discusses several important cases in which the pre-1840 Supreme Court cited foreign sources of law and includes a discussion of two important influences on the Court during that time: the law of nations and the civil law, particularly Roman law. Part III compiles and discusses many noteworthy cases decided during the years between 1840 and 1890, including both the infamous Dred Scott case and the well-known anti-polygamy case, Reynolds v. United States, which both strikingly made reference to foreign sources of law. Part IV discusses Supreme Court opinions citing foreign sources of law decided between 1890 and 1940, including The Paquete Habana, where the Court famously stated that international law is part of our law. Part V then concludes by discussing many of the opinions of the Court from 1940 to the present which cite foreign sources of law. In general, we believe our survey of the Court's practice shows a steady escalation in the citation to foreign sources of law with the modern references to foreign sources of law being definitely among the most striking. Part VI of this Article then concludes by analyzing all of the cases discussed in Parts II through V, addressing some of the unifying themes that appear in the Court's citation to foreign sources of law throughout its history. These themes include citing foreign law as a guide to determining reasonableness or the meaning of the open-ended ban on cruel and unusual punishment under the Eighth Amendment.

Our analysis of the Court's practice leads us to several conclusions. First, we believe those who say the Court has never before cited or relied upon foreign sources of law are clearly and demonstrably wrong. In fact, the Court has relied on such sources to some extent throughout its history. Second, the Court has, however, cited foreign sources of law with much more frequency in far more important constitutional cases in recent years, as Justice Scalia has suggested, and in addition the Court has tended to cite foreign sources of law in some of its most problematic opinions such as Dred Scott, Reynolds, and Roe v. Wade. This suggests Scalia is right to be wary of the Court's new trend in this direction. Third, as Professor Calabresi has argued elsewhere, citation to foreign law is most justifiable when the U.S. Constitution asks the justices to weigh whether a certain practice is reasonable, as it does in the Fourth Amendment, or whether it is unusual, as it does in the Eighth Amendment. In contrast, citation to foreign law is least justifiable when the Court is asked to determine whether an unenumerated right is deeply rooted in American history and tradition, as was the case in Lawrence, or whether a federal statute violates American federalism rules, as it was asked to do in Printz v. United States. In these cases, we agree with Justice Scalia that the Court's task is to interpret the original meaning of our Constitution and not to determine the current day reasonableness or unusualness of a legislative practice. We thus think, with Justice Scalia, that in the over-whelming majority of non-Fourth and Eighth Amendment, it will not be appropriate for the Supreme Court to cite foreign sources of law. Citation of such law is, in fact, a sign that the Court is falling into policy-making, as it did in Dred Scott, Reynolds, and Roe v. Wade, and this in turn suggests the justices are behaving illegitimately. We thus substantially agree with the spirit if not all of the substance of Justice Scalia's warning against citing foreign sources of law in U.S. constitutional cases.

Suggested Citation

Calabresi, Steven G. and Dotson Zimdahl, Stephanie, The Supreme Court and Foreign Sources of Law: Two Hundred Years of Practice and the Juvenile Death Penalty Decision (April 2005). Available at SSRN: or

Steven G. Calabresi (Contact Author)

Northwestern University - Pritzker School of Law ( email )

375 E. Chicago Ave
Chicago, IL 60611
United States

Stephanie Dotson Zimdahl

Northwestern University, School of Law, Students

Evanston, IL 60208
United States

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