During Elena Kagan’s June confirmation hearings, the newly confirmed associate justice of the U.S. Supreme Court twice addressed questions relating to her Jewishness. Sen. Lindsey Graham asked Kagan, in relation to a question about the Christmas Day Bomber, “Where were you on Christmas day?” Responded Kagan, to a deserved round of applause: “You know, like all Jews, I was probably at a Chinese restaurant.” In case there was someone out there who didn’t get the joke, Sen. Charles E. Schumer jumped in to explain: “No other restaurants are open.”The other instance related to her effusive 2006 introduction of Aharon Barak, the president of the Israeli Supreme Court from 1995 to 2006, who visited Harvard University’s School of Law when Kagan was dean, and who conservative critics said represents “judicial activism.” “I don’t think it’s a secret I am Jewish,” Kagan said. “The state of Israel has meant a lot to me and my family.” She went on to say, “I admire Justice Barak for what he’s done for the state of Israel and ensuring an independent judiciary.”“[Barak] was central,” Kagan continued, “in creating an independent judiciary for Israel and in ensuring that Israel—a young nation, a nation threatened from its very beginning in existential ways and a nation without a written constitution—he was central in ensuring that Israel, with all those kinds of liabilities, would become a very strong rule of law nation.”In her hearings before the Senate Judiciary Committee, Kagan stressed that she would not look to Barak’s judicial method as a model, saying the admiration she expressed in 2006 didn’t stem from his judicial philosophy or specific decisions.But a third issue was raised at the hearings, and no one spoke of its Jewish antecedents. The elephant in the room was stare decisis (“let the decision stand” in legal Latin). It means refraining from overturning settled matters, regarding them as binding precedent. As we shall see, the controversy over stare decisis has a long history and dates back to the development of Jewish Law, known in Hebrew as halakhah. Interestingly, the Justice’s position in this regard accords with halakhah, even if eating in unsupervised Chinese restaurants does not.Let’s look at American jurisprudence first.As Jessica Gresko of the Associated Press noted, “At Sotomayor’s hearings, the phrase [stare decisis] was used about as often as the phrase ‘wise Latina,’ two words Sotomayor took a beating over. For senators, both Democrat and Republican, stare decisis is a big deal. They want to know that as a justice Kagan will be committed to past court decisions and want assurances she won’t overturn them.”Stare decisis is not mentioned in the U. S. Constitution or in any specific law. In writing for the majority in Citizens United v. Federal Elections Commission, Chief Justice John Roberts wrote, citing precedent, that “stare decisis is neither an ‘inexorable command,’ nor ‘a mechanical formula of adherence to the latest decision.’” In this, Chief Justice Roberts (probably unbeknown to him, as a Catholic) reflected a basic tension in Jewish law.As a nominee, Kagan termed recent Supreme Court rulings upholding gun rights (McDonald et. al. v. City of Chicago and D.C. v. Heller) “binding precedent.” In response to a question from Sen. Chuck Grassley, who asked her if she’ll follow stare decisis “to uphold Heller and McDonald,” Kagan said she will, as she will for “any case,” leaving herself, as we shall see, some wiggle room.She also testified that the court’s rulings mandate that in any law regulating abortion “the woman’s life and the woman’s health have to be protected,” a reference toRoe v. Wade (which incidentally is also what Jewish law holds, according to a number of significant Jewish scholars).Kagan also acknowledged that the case known as Citizens United is “settled law.” In that controversial 5-to-4 decision, the Supreme Court, overturning two precedents, struck down portions of the McCain-Feingold Act and held that corporate funding of independent political broadcasts in candidate elections cannot be limited under the First Amendment, potentially opening the floodgates for corporate campaign-finance expenditures. The Citizens United decision has been much vilified and, to a lesser extent, praised.After demonstrating obedience to stare decisis, however, Kagan also testified, at a different time during the hearings, that the court should properly consider whether a “decision has proved unworkable over time, whether the decision’s doctrinal foundations have eroded, or whether the factual circumstances that were critical to the original decision have changed.” She thus apparently does not favor a doctrinaire application of stare decisis, but views it essentially as a rebuttable presumption; this is the “wiggle room” I referred to earlier and, as we shall see, accords well with the majority approach to halakhah.There is ongoing tension between binding precedent and “advisory precedent” in U.S., British (common), and Israeli law, among other legal systems. This tension between precedent and innovation is not new; in fact, it has been going on for thousands of years.It may be useful to consider the Talmud’s position.Talmudic study has always been about competing in a marketplace of ideas and making sometimes hairsplitting distinctions, all in the name of finding truth. Not only is the Talmud itself replete with controversy, but in the standard editions of the Talmud, of course, the text is surrounded by commentaries and supercommentaries, and thousands more glosses have been written over the generations, many in flat contradiction to previous annotations.What emerges out of all this seeming chaos is like the results of a spectroscopic analysis, with bands of different colors whose width represents the degree of consensus. On some issues, there is a wide band of a single color signifying broad agreement, while on others there is a colorful rainbow of narrow bands reflecting an enduring lack of consensus. Of course, the range of opinion is ultimately constrained by the Torah, which establishes immutable boundaries. The U.S. Constitution—even if, unlike the Torah, it is amended on rare occasions—functions somewhat similarly.Over the years, in a lengthy and evolutionary process, Jewish law, which was oral and made by rabbis, based on and limited by Torah mandates, ultimately became codified. Given the Talmud’s preference for inclusion and respect for multiple opinions, such codification was, to say the least, not without criticism and was approached cautiously.In fact, just the act of writing down rulings, or halakhot, was controversial. Writing the law down was opposed by the rabbis for more than a thousand years because written rulings are inherently less flexible. For this reason, other than the written Torah, known as Torah shebichtav, Jewish law was maintained as solely oral instruction, or Torah she-b’al pe, until political instability prompted Rabbi Judah Ha-Nasi and his rabbinic colleagues to redact the Mishnah, the older portion of the “oral law” in the late second century CE.Of course, judges and litigants alike all crave certainty, which well-written codes provide.The tension between binding precedent and advisory precedent continued for a long time, as did the evolution of Jewish codes.In the middle of the 11th century, Isaac b. Jacob ha-Kohen Alfasi, known as the Rif, compiled the Sefer ha-Halakhot, or Book of Laws, one of the earliest codes. It is arranged in the order of the Talmudic tractates, and embraces only the laws in practice at the time. Where earlier and later authorities disagree, Alfasi decided in favor of the latter, following the rule known as hilkheta ke-vatra’ei.Maimonides’ 12th century Mishneh Torah created a new literary form for the Codes, that of a book of “pesakim,” or book of statutes without reference to the Talmud or other sources. Maimonides made the shocking but unequivocal statement that anyone who referred to the Written Law and to his own book would know each and every detail of halakhah and have no need for any other book.This, exactly, was what Maimonides’ detractors objected to. Some, like Rabbi Yonah of Gerona even publicly burned copies of the Mishneh Torah (an action he later regretted). Codifications set the law in stone, and inherently violate the ancient precept that halakhah must be decided according to the later sages.The principle of hilkheta ke-vatra’ei essentially stands in opposition to the idea of codification that stare decisis represents. Maimonides’ embrace of stare decisis (at least from his day forth) engendered much controversy, with Rav Abraham b. David of Posquières, known as the Rabad, leading the opposition.Rabbi Menachem Elon, a professor who served as a justice on the Israeli Supreme Court from 1977 to 1993, and who was its deputy president from 1988 to 1993, commented on hilkheta ke-vatra’ei in his major work, Jewish Law: History, Sources, Principles. Elon notes that the rule that halakhah follows the later decisors dates from the Geonic period, from 589 to 1038. It laid down that until the time of Rabbis Abbaye and Rava, in the fourth century CE, halakhah was to be decided according to the views of the earlier scholars, but from that time onward, the halakhic opinions of post-Talmudic scholars would prevail over the contrary opinions of a previous generation.Rabbi Asher ben Yechiel, who lived from 1259 to 1327 and was known as the Asheri or Rabbenu Asher, or “our teacher, Rabbi Asher,” and is known to Yeshiva students simply as the Rosh, was a codifier. Despite this, he criticized Maimonides’ basic notion concerning the place of a “book of pesakim,” or codes, in Jewish law. He remarkably wrote, “If one does not find their [earlier] statements correct and sustains his own views with evidence that is acceptable to his contemporaries, he may contradict the earlier statements, since all matters that are not clarified in the Babylonian Talmud may be questioned and restated by any person, and even the statements of the Geonim may differ from his, just as the statements of the Amoraim [rabbis living from 200 to 500 CE] differed from the earlier ones.”“On the contrary,” Rosh writes, “we regard the statements of later scholars to be more authoritative because they knew the reasoning of the earlier scholars as well as their own, and took it into consideration in making their decisions.” He also warns that “all teachers err if they instruct from the statements of Maimonides without being sufficiently familiar with the Gemara (later part of the Talmud) so as to know where they were taken from … therefore no person should be relied upon to judge and instruct on the strength of his book without finding supporting evidence in the Gemara.”But historical events made the ongoing lack of a code untenable. The late 15th century saw the mass migration of Jewish communities, the expulsion of Jews from Spain, and the establishment of new centers of Jewish learning. Just as instability prompted Rabbi Judah to redact the Mishnah, so too, Rabbi Joseph Karo (1488-1575), himself a transplant to Safed, in the North of Israel (from his native Toledo, Spain, via Portugal, Bulgaria, Egypt, Salonica, and Constantinople), saw the urgent need for a comprehensive code. He called his work the Shulchan Aruch, or “the set table,” and compiled it from 1555 to 1558. It was first printed in Venice in 1565. The work was soon adapted to the customs of Ashkenazi Jewry with glosses written by Rabbi Moshe Isserles, who lived from 1520 to 1572 and was known as the Maimonides of Polish Jewry and later called the Rema. His work is referred to as haMappah, or “the tablecloth,” and was first published together with the Shulchan Aruch in 1569, during the lifetime of Rabbi Karo.Mindful of the criticisms leveled against Maimonides by the Rosh, Rabad, and others, the Rema cautioned against overreliance by judges on the Shulchan Aruch and on his own glosses, saying, “in any case, a judge must be guided only by what his own eyes can see,” sage advice that has all too often been forgotten. In any event, within a short time, the Shulchan Aruch together with HaMappah became the established starting point for deciding all questions of Jewish law in all Jewish communities worldwide, although Sephardic communities don’t always accept the opinions of Rabbi Isserles as binding.Common law, also known as case law, evolved similarly and tends to follow the rule of hilkheta ke-vatra’ei. As Rabbi Michael J. Broyde, a professor of Law at Emory University, points out, common law is definitely influenced by Jewish law. He wrote, “The great early writers of the common law had Maimonides’ code of Jewish law in front of them in Latin translation.”The British legal system has employed common law since the middle ages. It is also widely used in nations that trace their legal heritage to England as former colonies of the British Empire. These include the United States, to some extent, Malaysia, Singapore, Pakistan, Sri Lanka, India, Ghana, Cameroon, Canada, Ireland, New Zealand, South Africa, Hong Kong, and Australia.Common law is distinguished from statutory law in that decisions are based on previously decided cases, but prior cases need not be decisive. They are granted more or less weight in the deliberations of a court according to a number of factors:• Is the precedent “on point”? That is, does it deal with a circumstance identical or very similar to the circumstance in the instant case?• When and where was the precedent decided? A recent decision in the same jurisdiction as the instant case will be given great weight. Next in descending order would be recent precedent in jurisdictions whose law is the same as local law.• Does the precedent stem from dissimilar circumstances, older cases that have since been contradicted, or cases in jurisdictions that have dissimilar law? (These would be given least weight.)An example of the application of common law in a United States court is in the famous case of MacPherson v. Buick Motor Co., where then New York Court of Appeals Judge Benjamin Cardozo, who would later become the second Jewish justice on the Supreme Court, established a broad principle of liability for foreseeable danger that was nowhere codified; he based his decision on the judicial trend of predecessor cases over the years that progressively increased the standard for liability, granting more weight to recent decisions. It serves as a good example of the application of hilkheta ke-vatra’ei. And once again, Justice Cardozo’s decision pretty much follows halakhah as it relates to tort liability, or nezikin.At her confirmation hearing, Kagan was asked repeatedly whether her expressions of opinion in memos written when she was clerking for Justice Thurgood Marshall reflected a proclivity for overturning precedent or viewing cases through a policy-minded prism. She answered cautiously, saying that in her opinion, mere disagreement is not enough to warrant overturning a precedent. This cautious posture is entirely accordant to Jewish law.Perhaps it is Jewish law’s inherent elasticity and flexibility—bounded by the Torah but expressed in the freewheeling chaos of ongoing study—that has enabled Jewish law to renew itself and remain relevant after thousands of years. This might work in American law, as well.David E. Y. Sarna, a writer, investor, and technologist, is the author of History of Greed: Financial Fraud From Tulip Mania to Bernie Madoff.