NEW HAVEN — Two weeks ago, with the democracy protests in Hong Kong in full swing, China’s official People’s Daily newspaper labeled them “illegal” and called for protecting “the rule of law” in Hong Kong. Such statements left observers with little doubt about a central meaning “the rule of law” has in the People’s Republic: the Communist Party’s use of law to control and regulate society.

Yet there’s plenty of evidence that China sees the rule of law in far more nuanced and complex ways. Today the Communist Party’s 18th Central Committee starts its Fourth Plenum, and the main topic will be the rule of law in China — the first time in party history that a meeting with the authority of a plenary session will focus on the rule of law. And there are reasons for a measure of optimism that the plenum will demonstrate more complex views about the roles law can play and also take meaningful steps to advance new legal reforms.

Of course, legal reform has major limits in China’s one-party authoritarian system. There won’t be true judicial independence. All bets are off whenever the party sees a threat to its continued power; steps toward the rule of law don’t mean steps toward multiparty political democracy, which China’s current leaders totally resist. When the plenum issues its report, it will surely underscore that one central role of law is to maintain social order.

But, contrary to what pessimistic observers have predicted, the plenum is not likely to treat law as merely a tool for the party to control Chinese society, a throwback to the “Legalist School” of philosophy from 2,200 years ago which President Xi Jinping seems fond of quoting. Chinese society and its legal system have already changed too fundamentally for that, and the current regime led by Mr. Xi has already signed onto many reforms and even adjustments in ideology that represent positive steps toward a modern system of rule of law. These changes aren’t just window-dressing; they reflect the leadership’s recognition that it needs to improve governance, address widespread public grievances, and respond to public opinion.