The fact that the Chinese Communist Party (CPC) has become more objective in describing its past is a sign of maturity for the 90-year-old party, according to historians.

"No exaggeration of glory and no denial of failure. That's the attitude that should be adopted by a mature political party," says Yan Shuhan, a professor from the elite Central Party School of the CPC.

Yan is referring to the second volume of "History of the Chinese Communist Party" (1949-1978), which was published this year after 16 years of painstaking editing.

Editing the volume was difficult because of its coverage of controversial periods, including the Great Leap Forward of 1958 and the turbulent Cultural Revolution (1966-1976), experts say.

Yan said the way the CPC writes its history shows that a political party can only learn from experience by faithfully recording its past.

The publication not only acknowledges the Party's positive contributions, but also analyzes the causes of policy failures and the misjudgment of Party leaders, says Li Zhongjie, deputy director of the Party History Research Center of the CPC Central Committee.

Experts say that objectivity, a founding principle of the CPC, was virtually banished during the late 1950s and 1960s, when "extreme leftist" thought dominated the governing ideology of the Party.

Disgraced former senior Party officials such as Chen Duxiu, Wang Ming, Zhang Guotao and Lin Biao are generally treated fairly in the "History of the Chinese Communist Party," historians say.

The failure of Chen Duxiu, a key founding member of the CPC, to negotiate constructive cooperation between the CPC and the then-ruling Nationalist Party of China is no longer described as "a show of capitulation."

Instead, the failure is now blamed on collective "rightist" thought among CPC members led by Chen.

"People who made significant contributions to the Party's growth are fairly acknowledged in the book. A political party that takes the nation's prosperity and the people's happiness as its main responsibility can look back on its past in an objective manner," says Dai Yanjun, deputy head of the Party-building section of the Central Party School of the CPC.

Like Chen Duxiu, Lin Biao, who allegedly plotted to seize power from Chairman Mao Zedong in the early 1970s, was acknowledged in the book for his contributions in helping the Communists defeat the ruling Nationalist Party during China's civil war.

An entire chapter is devoted to the Cultural Revolution, a time during which many Chinese suffered because of poorly thought-out government policies.

"As long as we learn from the grave lessons of the Cultural Revolution, this book can help create a valuable spiritual legacy," the book reads.

"The new book faithfully depicts the Party's mistakes and their aftermath with no exaggeration or evasion," says Feng Xianzhi, the former director of the Party Literature Research Center of the CPC Central Committee.

"For all the mistakes the Party made in the past, the book gives an analysis instead of oversimplified criticisms," Feng says.

In February, two national conferences on the study of Party history were held in Beijing.

The country's historical research institutions and personnel were called on to improve their work to guide Party members in understanding the Party's history.

Chinese Vice President Xi Jinping said during the conferences that improving members' knowledge of Party history was of utmost importance to both the Party and the state itself.

About 1 million copies of the second volume of the "History of the Chinese Communist Party" have been sold as of mid-May, just four months since the book was published, the Party History Research Center of the CPC Central Committee said in a recent statement. The book has dominated sales rankings in major bookstores in Beijing for weeks.