Mr. Jiang occupied an increasingly rare space in China, finding ways to question authorities over crackdowns on dissent and limits on free expression while maintaining a prominent position in a country where opposition voices are often silenced.

“More and more people are genuinely interested in the fate of China’s rule of law,” Mr. Jiang said. He also conceded that the Chinese state has often moved in the opposite direction, including the tightening grip on power by President Xi Jinping.

There was a personal stake for Mr. Jiang. In the 1980s, as China began to move past the purges and persecution of Mao Zedong’s Cultural Revolution, Mr. Jiang was among four legal scholars who helped draft China’s first modern civil rights codes, which set basic legal principles such as due process in the legal system. But there were clear boundaries. Citizens, for example, still could not sue the Communist Party.

Mr. Jiang also had a hand in helping set the foundations for China’s future economic surge, crafting the framework for laws covering property rights, contracts and corporate rules. The work established Mr. Jiang’s reputation as one of China’s leading legal experts and a mentor for generations of rights activists and reformers. “Bow only to the truth,” was among his oft-quoted axioms.

Mr. Jiang decried censorship and indirectly chided Chinese leaders by asserting that the country’s economic modernization could not come at the expense of human rights and judicial accountability. Yet he did not cast himself as an impatient rebel. He believed that younger Chinese and future generations would eventually push leaders to accept more democracy and strengthen the rule of law.

“We should have a spirit of tolerance, which is to say: To what extent can we compromise with reality?” Mr. Jiang said. “Don’t feel bad about compromising. Time will slowly change everything.”

His ability to scold the system without incurring its full wrath added to his mystique in the eyes of his supporters. During the Tiananmen Square protests, Mr. Jiang was one of 10 university presidents who signed an open letter urging authorities to show restraint and open a dialogue with student demonstrators.

He staged a personal sit-in at the gates to his campus in solidarity with Tiananmen crowds. In an oral memoir made public in 2010, Mr. Jiang described two attributes that he believed were essential for intellectuals in China. “One is an independent spirit that does not succumb to any political pressure and dares to think independently,” he said. “The other is a critical spirit.”

Chinese authorities sent tanks and troops into Tiananmen Square in early June 1989 to crush the pro-democracy movement. The following February, Mr. Jiang was ousted as president of the China University of Political Science and Law, one of the centers of student organizing for the protests. Other university leaders seen as sympathetic to the Tiananmen crowds also were forced out.

Mr. Jiang was careful not to make public comments after being pushed out as president and was allowed to remain as a law professor. A friend, however, described to The Washington Post comments by Mr. Jiang at the time: “I’m maintaining my views,” Mr. Jiang was quoted by the friend as saying. “China must move toward democracy and the rule of law. … It has to come.”

Jiang Weilian was born on Dec. 28, 1930, in Dalian in northeastern China. His father was a bank employee; his mother was a homemaker.

He changed his name to Jiang Ping to protect his family from possible retribution during China’s civil war, which pitted Mao’s Communist forces against the rival Kuomintang, which was ruling China. Mr. Jiang left his university studies to join the Communist side in the war’s final years in the late 1940s.

After the Communist Party gained control in 1949, Mr. Jiang and other students were sent to the Soviet Union to continue studies. Mr. Jiang was dispatched to Moscow in 1951 to study law. He recounted a pivotal moment in shaping his political outlook: hearing news of a secret speech by Soviet leader Nikita Khrushchev denouncing the earlier purges and mass persecution by Joseph Stalin. For Mr. Jiang, the shifting views on Stalin were evidence that power could be challenged and reevaluated. (In 1981, Chinese leaders denounced some of Mao’s brutality but declared that his “contributions to the Chinese revolution far outweigh his mistakes.”)

Mr. Jiang returned to China in 1956 to take a teaching position at the Beijing College of Political Science and Law (now China University of Political Science and Law). Soon, however, he was caught up in Mao’s sweeping enforcement of strict Communist orthodoxy. Mr. Jiang — like many professors, writers and others — was assigned to labor crews for political “reeducation.” His wife, a classmate he met in Moscow, divorced him under political pressure.

While walking across a rail line with a load of steel pipes, he was struck by a train and one of his legs was mangled. He was fitted with a prosthetic leg that he wore the rest of his life.

In the late 1970s, as China began its outreach to the West, Mr. Jiang returned to his teaching position at the university and later was selected to help create the civil codes and other legal statutes aimed at supporting China’s new market-driven visions.

He grew increasingly critical of the overshadowing of the rule of law by what he called “rule by law,” the political leadership using the courts as a lever of power.

“Because the judicial system is tied to the political system, if there is no real political reform, the reforms to the judicial system cannot be fully realized,” Mr. Jiang told Reuters in 2014.

Mr. Jiang’s second wife, Cui Qi, died in July. Survivors include a son; a daughter; a sister, and two grandchildren.

Even as China grew to be a global economic power, Mr. Jiang described the leadership as deeply insecure — relying on force rather than dialogue when confronted with demands for greater freedoms during Tiananmen and the uprisings in Hong Kong.

“Democracy is best in supervision,” he told an interviewer. “We are always talking about improving the supervision mechanism. The best supervision mechanism is press freedom. … You can say whatever you have to say, and the leaders cannot suppress it. Free speech is the fundamental issue.”