Rise of the Samurai Lawyers

In the early 13th century, the warrior aristocracy of Christian Europe bound its ruling monarchs to a structured legal system—first with the Magna Carta in England in 1215, and then with a succession of other treaties across Europe. Slightly later, a complex code of moral norms and rules of conduct arose, aiming to restrain professional warriors. Force and power were now subjected to legal rules, and the path to constitutional government was underway.

That story is well-known to Americans and Europeans. But it is not the only such case. Something very similar happened simultaneously in East Asia. That change is the subject of an important new paper forthcoming from Peter Leeson, an economist at George Mason University. With "Anākī: The Law and Economics of Samurai Organization," Leeson examines the birth of the Kamakura Bakufu (literally "tent government") in medieval Japan.

The samurai were a class of skilled professional warriors, experts in deadly force. They were similar to European knights in many ways, but there was one major difference: They depended on others for any rights they had to land or its product. Specifically, they depended on the court aristocrats—the kuge.

These nobles had no real military power of their own and were not able to enforce order effectively in much of Japan. So they hired samurai, sometimes to provide military force but also as stewards and managers of lands: collecting dues from tenants, running estates, and sending income to the proprietor in the capital, Kyoto. The power between these two classes was asymmetric: In disputes between a proprietor and a samurai, judicial authority lay with the proprietor, making him a judge in his own case. In addition, the shiki—the warriors' bundle of rights attached to the land—were held on an almost at-will basis; a proprietor could easily terminate them. This led to exploitation and abuse, to the increasing fury of the samurai.

The kuge were able to get away with this for a while, because the samurai faced a collective action problem: The only way to use their military power against the court would be for a sufficiently large portion of their class to cooperate. Eventually this happened, in the Genpei War of 1180 to 1185. After his victory in that conflict, the samurai leader Minamoto Yoritomo created the Bakufu and based it in the city of Kamakura. After his sudden death, the Hōjō clan consolidated the institution.

The Bakufu was not a government that ruled all of Japan. It was a corporate body of samurai that provided governance services to its members, who were no longer under the jurisdiction of the court. The kuge government still existed and continued to exercise powers, but not over the members of the Bakufu. And the Bakufu did not include all samurai. So while the Bakufu had many attributes of a sovereign, it did not exercise that sovereignty over nonmembers. As Leeson puts it: "Kamakura-era Japan was a dual polity….'Warrior rule' belongs to later eras in Japanese history." An analogy in European history would be if a military order such as the Templars or Hospitallers had become a sovereign jurisdiction, but with even more members. In some ways, the Bakufu's position resembled that of the Roman Catholic Church in contemporaneous Europe.

Samurai who were members of the Bakufu were called gokenin, or honorable housemen. Only they could bring suit in Bakufu courts, so only they enjoyed its full protection and benefits. In return, they had to do military service for the organization and perform periodic guard duty at its headquarters in Kamakura. Membership was voluntary and largely hereditary. The Bakufu did not seek to expand its membership, partly because to do so would overburden its judicial system and dilute its quality, but also because it was sufficiently powerful that it did not need to. (Indeed, when it finally did expand substantially, in response to the threat of a Mongol invasion, that helped lead to the breakdown of the system in 1333.)

Gokenin could be appointed to two kinds of positions. The jitō shiki had shiki rights granted by the Bakufu rather than by a proprietor, but with the same responsibility to the proprietor. (This offered far greater security.) The other option was the shugo. That position entailed being a constable with various administrative powers, including enforcing some laws and prosecuting crimes.

Two important aspects to the Bakufu's structure ensured that it worked as a neutral arbiter, both between its members and between members and others. The first was that the Bakufu itself was not a major landlord or involved in running more than a very small number of estates. That meant it had no material interest in the outcomes of its cases. Its only real interest as an organization was that it be both effective and honest and be seen as such.

This stemmed from the second feature: the voluntary nature of its membership. If the Bakufu was not impartial, proprietors could organize resistance to it or break the agreement under which it operated. If it disappointed its members, they would defect and weaken its position militarily. So it had powerful incentives to be genuinely neutral and objective. In one important early decision, for example, Minamoto Yoritomo returned land conquered in the Genpei War to the court and the kuge.

The judicial services the Bakufu provided to its members were organized in a two-tier court system. The first was the Board of Coadjudicators (hikitsuke), made up of three to six chambers (usually five). Each chamber had a chairman and three to four senior judges as well as a number of court clerks. Above them was the Board of Councillors (hyōjōshū), which was a supreme court rendering final judgment but also was a deliberative body. It consisted of the chairmen of the chambers of the Board of Coadjudicators and the senior officers of the Bakufu—around two dozen people in all. The structure was thus straightforward and simple.

So was the procedure. Leeson sets this out in detail, drawing on the Sata Mirensho, a handbook drawn up in the latter part of the Bakufu's existence. The key fact here was that the Bakufu was a purely adjudicative body. It did not prosecute anyone itself; it merely provided a means for the parties in dispute to argue their case and have a decision reached and enforced. The court relied on both oral testimony and documents, but the latter was given greater weight; the process was transparent, with all parties having full knowledge of the other side's evidence and arguments. The final verdict contained a detailed exposition of the basis for the ruling and the reasoning employed to reach it. In short, there was due process.

The body of law that the court applied is laid out in the Goseibai Shikimoku, a compilation of norms and precedents drawn up in 1232. This text reveals a common law growing organically out of resolved cases. Those cases both generated and qualified precedents, which were then generalized to create a comprehensive and flexible law; the law so generated was qualified in turn by the principle of dōri—the samurai community's sense of natural justice. The law's main concerns were to restrain and regulate the authority of the Bakufu and its agents, to limit samurai violence, to ensure orderly inheritance and property transfer, and to prevent litigant abuse by affirming procedure.

Leeson argues that the system was effective, impartial, and predictable. Its effectiveness is revealed by the fact that it passed a market test: It did not lose clients or cases to other systems. Its impartiality can be seen in the surviving evidence of how cases were handled. And its predictability is demonstrated by the increasing frequency of out-of-court settlements—a phenomenon that emerged not because of vexatious costs but because outcomes were often predictable from precedent, making it sensible to arrive at a settlement with no further action. (Such private agreements still had to be ratified by the court to be enforceable.)

All this was a remarkable achievement. The samurai, after all, were trained killers. The temptation to exploit that and be predatory must have been considerable, and it doesn't take many defectors for a system to unravel. And yet the Kamakura Bakufu lasted 148 years.

This is a recurring challenge in human affairs, and not just in Japan and Europe. Protection against predation and enforcing individual rights requires the use of force; it cannot always be done through consensus, norms, or nonviolent sanctions. If that coercion is to be deployed in a way that enhances rather than undermines social stability, the people who deploy it—often some sort of warrior class—must protect themselves against other warriors while limiting their own power over the rest of society. If you limit internal conflict within the warrior group, you risk the possibility that the group as a whole will prey on everyone else; if you don't limit that conflict, you risk civil war or similar sorts of chaos. In both Japan and Europe, those challenges were handled with some success. But the route was different.

In 12th century England, for example, the reign of Stephen saw the second problem, with unrestrained conflict within the warrior class over property and inheritance rights. In response, Henry II enacted legal reforms. But then the monarch and his servants were able to use those legal processes to abuse the rest of the warrior class, not to mention everyone else. So the barons collectively rebelled and forced the king to agree to be bound by the system as well as running it. The agreement that established this was, of course, the Magna Carta.

Why did this process happen at opposite ends of Eurasia at roughly the same time? It might simply be a coincidence, but it might derive from common technological and military developments—notably, the reduced costs of certain kinds of weaponry, and an economic surplus that allowed a significant number of people to devote themselves full time to developing martial skills. Another parallel was the development of a code of conduct that, to some degree at least, restrained warriors' behavior. (This also happened in the Islamic world and in China.)

Whatever produced the process, it wasn't inevitable. The rule of law is not a natural or universal feature of human society; oppressive and arbitrary rule has been common throughout history. But sometimes, despite all the obstacles, a stable and relatively just legal order can arise.