The Supreme Court’s ruling in the name of liberty was therefore also, to a considerable extent, anti-discriminatory. A judgment apparently allied with capital actually protected Chinese workers’ right to choose overtime and compete fairly.

Right and wrong are not so easy to separate. In each era and concrete setting, law reflects the contest among different interest groups.

Law is not a natural and immutable set of rules or a final answer bestowed from heaven. It is a human choice. It frequently embodies society’s judgments, measurements, and comparisons among values, and many of its most important collective decisions.

Consider another old case. The United States is an immigrant society. Early settlers crossed the ocean on ships such as the Mayflower, drawn not only by religious conflict but by America’s vast, seemingly unoccupied land. The earliest American judicial system was therefore built around property: how private ownership should be protected. Contract and criminal law later developed on that foundation.

Property remains a compulsory first-year law-school course. Yet in today’s complex commercial society, I was astonished that our first property lesson concerned an extremely simple dispute over a fox.

The case was older than the Bakeshop Act, dating to 1805.

The facts were simple. In an age of hunting, a man and his hound found a fox’s trail and began a long pursuit. Through dense woods the fox kept escaping, and the hunter never quite caught it.

After chasing it for half a day, the hunter finally saw the fox—just as someone else intercepted it. A stranger appeared midway and seized the exhausted, dying animal. The two men carried their dispute over the fox into court.

This too was a New York case, and it remains foundational in property law today. Why?

The apparent quarrel over a fox contains deeper questions: how society understands property, how it chooses to allocate it, and how it decides who should own what.

Intuition and sympathy may favor the pursuer, who invested enormous effort, whereas the second man seems a classic free rider.

Awarding the fox to the pursuer would affirm the value of labor. Should a thing belong to the person who expended the greatest effort on it?

That result seems closer to justice.

Yet the court awarded the fox to the latecomer who captured it. The reason was that certainty mattered most in determining ownership.

As we said, one important social value of law is certainty.

Who worked hardest to chase this fox is quite uncertain. It may look clear here, but what about the next fox, pursued by three, five, or a dozen people? How can society decide who labored most or who fired the fatal shot? It is difficult.

Who seized and physically possessed the fox, however, is certain. Property law chose that certainty. Between the judge’s intuitive justice and the social interest to be achieved, the latter prevailed. Thus law is a human choice.

Both examples come from the United States. Some may ask whether American law will be our principal example. Yes—but not merely because it is the system I seriously studied, qualified in, and feel equipped to explain.

Nor because the American legal system is perfect or should be copied.

The United States is nevertheless a distinctive nation that claims—and in some respects has—to have been founded through law, and it presents itself as a society grounded in the spirit of law.

America belongs to the common-law tradition, in which precedent is the principal basis of adjudication, unlike China’s civil-law tradition centered on written statutes. Much of the time, what earlier judges decided is law, and their interpretations become part of law.

Law students read casebooks. The ordinary English word for a teaching book is textbook; only law students carry thick casebooks—volumes made from many cases rather than a text that states the doctrine. Students must discover the reasoning and legal spirit within the decisions themselves.

Understanding litigation in a case-law system is therefore a journey of argument and analogical analysis, searching for similarities and distinctions. For favorable cases, find parallels in background, principle, purpose, emotion, and every possible dimension. For unfavorable cases, distinguish them.

A statute-based system says to follow the code, but no statute can encompass everything in the world. Courts increasingly seek practical experience and methods in earlier decisions. I practise in Japan, also a civil-law country, and every analysis for a client cites precedents as well as statutes, because those cases powerfully show how Japanese judges interpret and apply the law in reality.

China combines statute and custom. We do not formally have precedent, yet the Supreme People’s Court increasingly issues Guiding Cases. Lower and intermediate people’s courts are not theoretically bound by earlier Supreme Court decisions, but usually consult them—if only because reversal by a higher court affects a judge’s performance evaluation.

Common law can be more certain because today’s judge must follow yesterday’s. It can also be less certain because circumstances change, every person’s story differs, and many questions have never been answered by an earlier judge.

Perhaps because law cannot always give an indisputable answer, we must continually argue rather than merely recite a book. We must repeatedly answer questions about law’s nature, function, and meaning, and return to abstractions such as justice. When may expediency override a rule, and which principles must never change?

Case law originated in England and remains prevalent in Commonwealth countries and former British colonies. Though American history is short, its courts may still consult English precedents from the seventeenth and eighteenth centuries. Americans readily use law to settle matters large and small, producing vast archives of cases. Their stories reveal useful logic and principles, much experience worth borrowing, and many questions worth reconsidering.

Before studying law, I had never imagined such complexity. My understanding was simple.

Applicants to American law schools write a personal statement explaining why they want to study law. After long thought, I chose a theme that felt conventional and naive: justice.

My interest in law began with Sidney Sheldon’s novel The Rage of Angels. Jennifer, a lawyer of ordinary origins, struggles through life, falls, and becomes entangled in vengeance, organized crime, and politics before returning to ordinary legal practice.

At the end, she walks onward, continuing to seek an invisible and intangible justice.

Law then seemed romantic to me, and being a lawyer looked exciting and cool.

Harvard is a strongly liberal place filled with idealists. Talking with my American classmates, I discovered that nearly all of us had written about justice in our personal statements.

Law school quickly demolished our idealism. We saw that law was not simple and did not invariably realize justice. It was a complex set of rules, constantly rewritten, interpreted, and even exploited.

Our civil-procedure professor, William Rubenstein, one of America’s leading scholars in the field, compared legal practice to poker. Litigation, he said, gives every lawyer a hand containing many possible combinations.

That hand contains more than justice and facts. It includes intricate procedure and doctrine, a judge’s preferences, and public opinion at the time.

It includes the composition of the jury—their gender, race, religion, and mood—and superficial matters: does a witness look honest and reliable? Does a client appear sympathetic? All are cards a lawyer must learn to play.

Legal dramas accustom us to brilliant courtroom speeches, where a heroic lawyer decides life and death with an impassioned closing argument. Reality rarely works that way. More than ninety percent of cases never reach trial. Months or years of struggle pass between filing and resolution; by closing argument, few surprises remain.

Outcomes are often determined not by obvious right and wrong, guilt or innocence, but by minor details. Courtroom argument is less spectacular than it looks. Rather than forever debating justice and fairness, lawyers often dispute the definition of one word or the legality of a small procedural step. It is painstaking work.

Law resembles debate: a competition in argument whose result is not as clear, certain, or standard as it appears.

The United States is a common-law country, using cases as legal authority. China and most European countries are civil-law jurisdictions with written codes.

The traditions have different judges. A common-law judge works in an adversarial system as a relatively passive arbiter, not personally gathering evidence or investigating the merits. The parties present the evidence, and the judge decides.

A civil-law judge is inquisitorial, closer to the Chinese image of an upright magistrate who actively investigates a case. The broad trend, however, is toward more adversarial proceedings.

Some may doubt that such a form can deliver justice. Its premise is that everyone receives a full opportunity to speak, after which an entirely independent third party determines responsibility.

We may discuss and question both the principle and its practical feasibility, but we cannot deny the reality of our age. We no longer live in an era of the perfectly upright magistrate; we cannot wait for one just decision-maker to distinguish every right and wrong and vindicate us.

In reality we constantly face problems and rules. We must use the different cards in our hands to pursue our interests. Such struggle and thought do not belong only to the courtroom, though courts are full of both; they are part of life.

A lawyer’s way of thinking means considering how to play every card when advancing a client’s interests and handling a case—testing every possible route to obtain every possible advantage.

Where should I sue? Do local relationships, ideology, racial composition, and economic conditions favor me? Do people there support Trump or Obama, and will they sympathize with my client?

When should I sue? How should a judge’s style alter my strategy? These apparently minor choices ultimately determine success or failure, and each constrains and affects the others.

A lawyer first thinks pragmatically. Before constructing a grand argument, look for a low-cost procedural shortcut. Before proving your case, find a missing link in the opponent’s logic to attack.

It also requires creativity, especially in case-law jurisdictions. Novel situations arise, earlier judges have never decided comparable facts, and sometimes you must change the law to secure your interest.

During America’s path toward recognizing same-sex marriage, a baker refused to make a wedding cake for a same-sex couple. On its face this looked like a sales contract, a matter of contract law. One defense argument reframed it as the baker’s right to freedom of speech.

Likewise, US affirmative-action policies give Black and other minority students certain preferences, prompting claims of reverse discrimination. Lawyers and judges defending them ask us to change perspective: rather than compare treatment of Black and white students individually, view the whole; then the policy is not unequal treatment but diversity.

There are many such stories. Law is a set of rules and a contest of arguments under those rules. Its standard of justice is inherently indistinct, changes with the age, and is interpreted and applied differently across settings.

I do not know whether this shakes your confidence in law, as mine was shaken when the mountain ceased to look like a mountain early in my studies.

Professor Rubenstein once told our final class why he studied law. As a child, his parents tried to motivate him, as many parents do, by taking him to the heavy-industrial city of Pittsburgh. They showed him laborers working painfully hard and warned that if he did not study, he too would have to sell his physical labor.

He entered Harvard and became a highly successful lawyer, only to find no real difference: instead of selling physical labor to capital, he sold mental labor. That felt even more frightening, he said, like laying one’s brain on the table for the highest bidder to use.

That resembles the critical public view of lawyers and, to some extent, the profession’s practical ethic. Yet he asked us always to remember what we wrote in our law-school statements: never forget why you chose law, and remember that some things can never be sold.

Thinking like a lawyer is unavoidably realistic. Judges are not infallible magistrates but human beings. Lawyers are not always gentlemen; sometimes they must choose ruthlessly creative means. Yet these habits of thought may still offer insight into analyzing and solving real problems.

Our point of entry is therefore the lawyer’s actual reasoning in a difficult case: confronting the full litigation process, fighting at every step, choosing when and where to sue, collecting and preserving evidence, using complicated procedure both for shortcuts and for strategic delay, selecting witnesses and jurors, defending a position with seemingly unrelated precedents, and extracting principles from a vast archive of contradictory decisions.

We will introduce landmark cases that changed history, not simply to relive the past but to examine the brilliant performances, imagination, and reasoning of lawyers and judges—along with their gossip, human prejudices, and foresight.

Law and precedent are not omnipotent. Society keeps changing; many cases become obsolete, and many questions have never been answered. What should we choose then?

We must return to grand concepts such as fairness and justice and to law’s purposes. Contract law should let people cooperate with confidence; property law should let them earn with confidence; criminal law should leave vengeance behind for punishment and prevention. Constitutional questions ask what kind of society we want to inhabit. Let us explore them together.