China’s ruling Communist Party will likely never open all the files on its recent painful past, including the Cultural Revolution and Great Leap Forward, and sees no need to reassess those periods, a senior party historian said Monday.

The 1958-1961 Great Leap Forward, when millions starved to death in Mao Zedong’s botched industrialization campaign, and the 1966-1976 Cultural Revolution are two of modern China’s most sensitive historical events.

During the Cultural Revolution, children turned on parents and students on teachers after Mao declared class war, convulsing the country in chaos and violence.

While recent years have seen increased public discussion of both events, certain topics remain almost completely off-limits, including the death of Lin Biao, once handpicked to succeed Mao but killed in a mysterious plane crash in 1971 while fleeing China having been accused of plotting a coup.

Xie Chuntao, director of the Party History Teaching and Research Department of the Party School, which trains rising officials, said the party has reflected deeply on its mistakes.

But former paramount leader Deng Xiaoping’s conclusion that Mao made mistakes remains the correct way to broadly view the period, Xie told a news conference.

“I believe this summation is still, to this day, authoritative and has withstood the test of time,” he said, in rare public comments by a party official on the country’s fractious communist past.

The mistakes of the party’s past are still being learned today by its members, and he himself teaches his students about the Great Leap Forward, Xie said.

“Everyone has reached a consensus that the mistakes of the past will certainly not be repeated today or in the future.” Only a “small number” of the party’s historical files were still sealed, he said.

“Some involve the state’s core interests, and some are not convenient to be released,” Xie said. “From a historical research it is to be hoped that it would be best if they are all opened. But I fear this cannot happen, and may never happen.”